Book HB 38-1

R Rosa-Rodríguez et al. closed hydroponic system and 46.03 frequency) to satisfy the water demand, system (Table 1). The nutrient quantities g L-1 in the open system. The closed but without excessive drainage (El- applied per kg of fruit were 16.09 and system produced 26.9% more fruit per Mageed & Semida, 2015). 20.81 g for the closed and open systems, liter of water than the open system. respectively. These quantities were In hydroponic culture systems with At the end of the crop cycle in the obtained considering N, P, K, Ca and recirculation of NS under automatized open system, 78,500 L of water were lost Mg. Higher quantities of fertilizers were greenhouse conditions, it is possible to as the solution discarded in drainage, reported by Ojodeagua et al. (2008), obtain up to 67 kg fruit per cubic meter which represents 98.8% more than the who found 27.8 g nutrients (consider N, of water, and up to 45 kg in a system closed system that lost only 900 L as P2O5, K2O, Ca, and Mg) per kilogram of with non-recirculating nutrient solution discarded solution in drainage during fruit produced. (Stanghellini et al., 2003). the entire crop cycle (Table 1). The quantities of nutrients (in grams) Drained percentage Nutrient and fertilizers quantities per cubic meter of NS in both systems and use efficiency were: N= 175.9, P= 54.8, K= 267.1, Ca= The percentage of drained NS 171.0, Mg= 82.1 and S= 207.3. Thus, (%D) varied from 25 to 34% in both The total average quantity of they represented approximately 45.8% systems (Table 2). This quantity of NS fertilizers per month applied during the of the applied fertilizers. Nutrient uptake was reused in the closed system and crop cycle (April-November) varied by the plants is affected by several eliminated only three times:1) during from 11.04 kg to 105.1 kg, in the months factors, such as ionic concentration the initial stage of fruit formation; 2) of lowest and highest application, in the NS, the selectivity of the roots, in full production stage; and 3) at the respectively. In the open system, we climate and plant development stage end of the crop cycle. Together, this applied 164.22 kg of fertilizers more (López et al., 2011). The uptake of accounted for only 0.31% of the applied than in the closed system. In addition, nutrients is affected by the balance NS. In contrast, in the open system, all in the closed system the amount of existing among them, which in closed the drained solution was lost. When fertilizers decreased in 27.14% during systems is the main factor to maintain the plants had higher requirements of tomato crop cycle, in comparison to an optimal plant nutrition (Kempen et water, the drained quantity decreased the open system (Table 1). This was al., 2016). in the first months of the crop (Table because of the recirculation of the NS. 2). Therefore, it is necessary to modify The use efficiency of the fertilizers was For each kg of fertilizers, 28.45 kg the irrigation schedule (mainly time and higher in the closed system, with 22.6% of fruits were produced in the closed more efficiency as compared to the open system, while in the open system, production was 22.00 kilogram of Table 2. Nutrient solution applied, drained and percentage drained on a typical day of each fruits per kilogram of fertilizers. In month of the tomato crop cycle grown in two hydroponic systems: open and closed. Mexico, the closed system, 6.45 kg more fruits Academic Unit of Agronomy, Autonomous University of Zacatecas, 2017. were produced as compared to the open system. These results are due to Month of the Volume applied Volume collected Percentage the recirculation of the NS since this crop cycle allows reducing the water and fertilizers per plant (mL) per row (L) drained (%) used (Pardossi et al., 2011, Sánchez-Del Castillo et al., 2014, Moreno-Pérez et April 432.84 9.28 32 al., 2015, Kempen et al., 2016). May 873.16 18.13 31 Yield June 2460.32 41.21 25 The mean fruit yield was 20.2 kg m-2. There were no differences by effect of July 2970.08 51.73 26 the evaluated treatments (Table 3), nor there was a difference in the categories August 3147.86 56.94 27 measured in the weight of the harvested fruits. Nevertheless, the yield was September 3050.12 59.26 29 achieved with greater productivity in the use of water and nutrients with October 2587.23 53.73 31 recirculation of NS in the closed system. With this practice, we can reduce water November 2390.75 54.46 34 consumption up to 33%, N use in 59%, P applications in 25%, and K use in 55% Table 3. Percentage of tomato fruits sorted into four weight grades and fruit yield by effect as compared to the open system, with of two hydroponic systems, closed and open, in a crop cycle from March to November (n= the possibility of obtaining higher yield 8). Mexico, Academic Unit of Agronomy, Autonomous University of Zacatecas, 2017. with lower production costs and less pollution (Grewal et al., 2011). Treatment Fruits in four quality grades (%) Yield (kg m-2) Importantly, our results were 29% 1† 2 34 Closed system 38 a‡ 47 a 10 a 4 a 19.6 a Open system 40 a 46 a 11 a 4 a 20.8 a †1st grade (>130 g per fruit); 2nd grade (100-130 g per fruit); 3th grade (60-99.99 g per fruit); 4th grade (<60 g per fruit). ‡Values in a column followed by the same letter are statistically equal (Tukey, p≤ 0.05). 50 Horticultura Brasileira 38 (1) January - March, 2020

Water and fertilizers use efficiency in two hydroponic systems for tomato production Figure 1. Open and closed hydroponic systems. Mexico, Academic Unit of Agronomy, cerrado. Interciencia 42: 236-341. Autonomous University of Zacatecas, 2017. DE WRACHIEN, D; GOLI, MB. 2015. Global higher than those reported in commercial concentration of solutes (nutrients) than warming effects on irrigation development greenhouses with grafted tomato plants the water (solvent), thus increasing EC and crop production: A world-wide view. (Pardossi et al., 2011). Coincidently, (Dorai et al., 2001). Agricultural Sciences 6: 734-747. they found no differences in yield between a closed and an open system. In conclusion, we did not find DORAI, M; PAPADOPOULOS, A; GOSSELIN, differences in yield between the closed A. 2001. Influence of electric conductivity Throughout the tomato harvest, the and open systems tested. Nonetheless, management on greenhouse tomato yield and treatments had no effect on fruit size. fertilizers and water use efficiency fruit quality. Agronomie 21: 367-383. The first and second quality grades were higher in the closed system, (>130 g and 100-130 g, respectively) with concomitant economic and EL-MAGEED, TAA; SEMIDA, WM. 2015. Effect were predominant in both treatments environmental benefits. Since the closed of deficit irrigation and growing seasons on with no significant differences (Table 3). system was more efficient regarding plant water status, fruit yield and water use the open system, this makes the former efficiency of squash under saline soil. Scientia Electric conductivity and pH of system a good alternative to produce Horticulturae 186: 89-100. nutrient solution tomato and to preserve the resources involved in the process (like water and FLORES, J; OJEDA-BUSTAMANTE, W; The pH value of NS was maintained fertilizers) and in the environment by LÓPEZ, I; ROJANO, A; SALAZAR, I. reducing pollution. 2007. Requerimientos de riego para tomate between 5.5 and 6.0 and EC between de invernadero. Terra Latinoamericana 25: REFERENCES 127-134. 1.8 and 2.3 dS m-1, depending on the CASIERRA-POSADA, F; AGUILAR- GREWAL, HS; MAHESHWARI, B; PARKS, crop stage as recommended by Putra & AVENDAÑO, ÓE. 2008. Calidad en frutos de SE. 2011. Water and nutrient use efficiency tomate (Solanum lycopersicum L.) cosechados of a low-cost hydroponic greenhouse for a Yuliando (2015). The changes in these en diferentes estados de madurez. Agronomía cucumber crop: An Australian case study. Colombiana 26: 300-307. Agricultural Water Management 5: 841-846. variables were gradual to attenuate the COSTA, E; ESPÍRITO SANTO, TL; BATISTA, HERRERO, B; BLÁZQUEZ, ME; CRISTÓBAL, impact in yield of crop. TB; CARVALHO, TMR. 2018. Diferentes MD. 2014. Agronomic parameters assessment tipos de ambiente protegido e substratos in hydroponic tomato crop. Horticulura In drained NS, pH oscillated between na produção de pimenteiras. Horticultura Brasileira 32: 385-390. Brasileira 35: 458-466. 6.3 and 7.2, which depended on the KEMPEN, E; AGENBAG, A; DECKERS, S. DE LA ROSA-RODRÍGUEZ, R; AVELAR- 2016. Variations in water and macronutrient ammonium/nitrate ratio. In NS that MEJÍA, JJ; LARA-HERRERA, A; LOZANO- uptake of soilless tomato as affected by the GUTIÉRREZ, J; ESTRADA-CASILLAS, J; nutrient solution composition. South African supply N-NH4+, pH tends to descend, CASTAÑEDA-MIRANDA, R. 2017. Agentes Journal of Plant & Soil 1: 1-10. while in those that supply N-NO3-, pH fitopatógenos en la solución nutritiva para el cultivo de jitomate en un sistema hidropónico KOMOSA, A; PIROG, ZJW; MARKIEWICZ, rises (Savvas et al., 2006). The EC of B. 2011. Comparison of yield, nutrient solution changes and nutritional status of the drained NS increased to values from greenhouse tomato grown in recirculating and non-recirculating nutrient solution systems. 3.1 to 5.5 dS m-1, with a mean of 4.49 Journal Plant Nutrition 34: 1473-1488. dS m-1 during the crop cycle. This is KRAUSE, M; MONACO, P; HADDADE, I; MENEGHELLI, L; SOUZA, T. 2017. because the plant uptakes proportionally Aproveitamento de resíduos agrícolas na composição de substratos para produção de more water than nutrients. If we also mudas de tomateiro. Horticultura Brasileira 35: 293-298. take into consideration the amount of KUŞÇU, H; TURHAN, A; DEMIR, AO. 2014. water lost through evaporation, the The response of processing tomato to deficit irrigation at various phenological stages in a drained solution would have a higher sub-humid environment. Agricultural Water Management 133: 92-103. Horticultura Brasileira 38 (1) January - March, 2020 LEWIS, AH; MARMORY, FB. 1940. Nutrient uptake by the tomato plant. Journal of Pomology and Horticultural Science 17: 275-283. LÓPEZ, PP; CANO, MA; RODRÍGUEZ, RG. 2011. Efecto de diferentes concentraciones de potasio y nitrógeno en la productividad de tomate en cultivo hidropónico. Tecnociencia Chihuahua 5: 98-104. MAGAÑA-LIRA, N; PEÑA-LOMELÍ, A; SÁNCHEZ-DEL CASTILLO, F; RODRÍGUEZ-PÉREZ, JE; MORENO- PÉREZ, EDC. 2013. Comportamiento productivo de híbridos F1 de tomate y sus poblaciones F2. Revista Fitotecnia Mexicana 36: 371-379. MORENO-PÉREZ, EDC; SÁNCHEZ-DEL CASTILLO, F; GUTIÉRREZ-TLAQUE, J; GONZÁLEZ-MOLINA, L; PINEDA- PINEDA, J. 2015. Greenhouse lettuce 51

R Rosa-Rodríguez et al. production with and without nutrient solution di biologia delle painte Agrarie, University of STANGHELLINI, CK; EMPKES, FLK; KNIES, recycling. Revista Chapingo Serie Horticultura Pisa, (Chapters 1 and 4). 21: 43-55. P. 2003. Enhancing environmental quality in PUTRA, PA; YULIANDO, H. 2015. Soilless OJODEAGUA, JL; CASTELLANOS, JZ; culture system to support water use efficiency agricultural systems. Acta Horticulturae 609: MUÑOZ, JJ; ALCANTAR, G; TIJERINA, L; and product quality: A review. Agriculture and VARGAS, P; ENRÍQUEZ, S. 2008. Eficiencia Agricultural Science Procedia 3: 283-288. 277-283. de suelo y tezontle en sistemas de producción STEINER, AA. 1984. The universal nutrient de tomate en invernadero. Revista Fitotecnia SÁNCHEZ-DEL CASTILLO, F; GONZÁLEZ- Mexicana 31: 367-374. MOLINA, L; MORENO-PÉREZ, EDC; solution. pp. 633-650. In: Proceedings 6th PINEDA-PINEDA, J; REYES-GONZALES, International Congress on Soilless Culture. PARDOSSI, A; CARMASSI, G; DIARA, C; CE. 2014. Dinámica nutrimental y rendimiento Wageningen, The Netherlands. INCROCCI, L; MAGGINI, R; MASSA, D. de pepino cultivado en hidroponía con y sin SAVVAS, D; PASSAM, HC; OLYMPIOS, C; 2011. Fertigation and substrate management recirculación de la solución nutritiva. Revista NASI, E; MOUSTAKA, E; MANTZOS, N; in closed soilless culture. Pisa: Departmento Fitotecnia Mexicana 37: 261-269. BAROUCHAS, P. 2006. Effects of ammonium nitrogen on lettuce grown on pumice in a closed hydroponic system. Horticultural Science 41: 1667-1673. 52 Horticultura Brasileira 38 (1) January - March, 2020

Research RAGASSI, CF; CARVALHO, ADF; SILVA, GO; PEREIRA, GE; PEREIRA, AS. 2020. Performance of advanced potato genotypes in organic and conventional production systems. Horticultura Brasileira 38: 53-57. DOI - http://dx.doi.org/10.1590/S0102-053620200108 Performance of advanced potato genotypes in organic and conventional production systems Carlos Francisco Ragassi 1ID; Agnaldo DF de Carvalho 1ID; Giovani Olegário da Silva 1ID; Gabriel Emiliano Pereira ;1,2ID Arione da S Pereira 3ID 1Embrapa Hortaliças, Brasília-DF, Brasil; [email protected]; [email protected]; [email protected]; 2Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília (UnB), Brasília-DF, Brasil; [email protected]; 3Embrapa Clima Temperado, Pelotas-RS, Brasil; [email protected] ABSTRACT RESUMO Potato is responsive to intensive agricultural input use; however, Desempenho de genótipos de batata em sistema orgânico e it can be produced in less intensive production systems (such as the convencional de produção organic system) by using appropriate production techniques and genotypes adapted to this system. This study aimed to evaluate the Embora seja responsiva ao uso intensivo de insumos agrícolas, a performance of advanced potato genotypes for tuber yield under batata pode ser produzida em sistemas de produção menos intensivos, conventional and organic production systems, in order to select como o sistema orgânico, por meio do uso de técnicas de produção potential genotypes to become new cultivars adapted to these systems. adequadas e genótipos adaptados. Nesse contexto, objetivou-se Fifteen advanced potato clones and two controls were evaluated under avaliar o desempenho de clones avançados de batata para caracteres organic and conventional production systems, in 2016 and 2017, in componentes do rendimento de tubérculos em sistemas orgânico e Brasília-DF, Brazil. The experimental design was randomized blocks convencional de produção, para a definição dos clones com maior with three replicates and plots composed of two rows with 10 plants potencial para se tornarem novas cultivares, adaptadas a esses each, spaced 0.35 m between plants and 0.80 m between rows. Total sistemas. Foram avaliados 15 clones avançados de batata e duas (mass) and marketable (mass and number of tubers) productivities cultivares testemunhas em sistemas orgânico e convencional de were evaluated. Variance analysis showed significant differences cultivo, nos anos 2016 e 2017 em Brasília-DF. O delineamento among genotypes for all traits. Despite the lower average tuber experimental foi blocos ao acaso com três repetições e parcelas yield in the organic system, selecting genotypes with high potential compostas por duas linhas com 10 plantas cada, espaçadas 0,35 m productivity was possible in this system, such as F158-08-01 and entre plantas e 0,80 m entre linhas. Foram avaliadas a produtividade F158-08-02, showing high marketable tuber yield, with values total (massa) e comercial (massa e número de tubérculos). A análise equivalent to the conventional system. Clones F102-08-04, F13-09- de variância mostrou diferenças significativas entre os genótipos 07, F-18-09-03, F-183-08-01, F-21-09-07, F31-08-05, F63-10-07 and para todos os caracteres. Apesar do menor rendimento médio de F97-07-03 also outperformed the control cultivars in organic system. tubérculos em sistema orgânico, foi possível selecionar clones com For conventional system, F158-08-01, F158-08-02 and F183-08-01 elevado potencial produtivo neste sistema, principalmente os clones were superior, and F18-09-03, F21-09-07, F63-10-07, F97-07-03, F158-08-01 e F158-08-02, com elevado rendimento de tubérculos PCDINV10 and PCDSE090 showed performance similar or superior comerciais, equivalentes ao do sistema convencional. Além destes, to the most productive control (cultivar Asterix). Genotypes F158-08- os clones F102-08-04, F13-09-07, F-18-09-03, F-183-08-01, F-21- 01 and F158-08-02 were superior in both conventional and organic 09-07, F31-08-05, F63-10-07 e F97-07-03 também superaram systems, with potential to become new cultivars recommended for as cultivares testemunhas no sistema orgânico. Para o sistema both production systems. convencional, os clones F158-08-01, F158-08-02 e F183-08-01 foram superiores e os clones F18-09-03, F21-09-07, F63-10-07, F97-07-03, PCDINV10 e PCDSE090 apresentaram desempenho semelhante ou superior à testemunha mais produtiva (cultivar Asterix). Os clones F158-08-01 e F158-08-02, portanto, foram superiores em ambos os sistemas e possuem potencial para se tornarem novas cultivares com recomendação para esses dois sistemas de produção. Keywords: Solanum tuberosum, agronomic evaluation, production Palavras-chave: Solanum tuberosum, avaliação agronômica, systems. sistemas de produção. Received on March 8, 2019; accepted on January 7, 2020 Potato is the third most important 2015). Brazil produces about 3,854,054 t ha-1 (IBGE, 2019). The process of human food source, being only t of potato yearly, in an area of 125,548 adoption of modern cultivation technique surpassed by rice and wheat (FAOSTAT, hectares, with an average yield of 31.78 with investment in mechanization, Horticultura Brasileira 38 (1) January - March, 2020 53

CF Ragassi et al. irrigation, fertilization, quality of potato This study aimed to evaluate (40 to 50 mm diameter) tubers harvested seeds and more effective control of pests agronomic performance of advanced from a conventional production field and diseases results in the increasing potato genotypes, using tuber yield in planted with basic class tubers. The productivity levels registered during the organic and conventional production potato seeds were stored in a cold last decades. The productivity increase systems for selecting those which show chamber at 4°C for 5 months before is possible because potato crop shows higher potential to become new cultivars implanting the experiments. For 2017 a very remarkable response to the adapted to both production systems. cultivation, we used seed tubers of crop management techniques, such as, the same size class, obtained from the the application of large quantities of MATERIAL AND METHODS previous harvest in each system and fertilizers (Silva et al., 2018a), or an stored in a cold chamber following efficient chemical control of pests and The experiments were installed in harvest, at the same temperature, for diseases. the experimental fields of Embrapa 8 months. Hortaliças in Brasília-DF (15º55’44”S, Potato crop can respond very well to 48º08’29”W, 999 m altitude and Soil chemical characteristics at 0-20 improved management factors, it is also 15º56’30”S, 48º08’22”W, 999 m cm depth according to the analyses possible to grow potato in less intensive altitude), one experiment being carried carried out in the first year of the production systems, though, such out under conventional system and experiment (implementation of the as the organic cultivation. However, the other under organic system during experiments) in organic system were: nutrients are less concentrated in an the dry winter harvest (from May organic matter = 26.3 g dm-³; pH (H2O) organic system when compared with to September), 2016 and 2017. We = 5.9; P (Mehlich) = 6.9 mg dm-3; K = a conventional production system, evaluated advanced potato genotypes 313 mg dm-3; Ca = 1.9 cmolc dm-3; Mg = this latter one relying on high doses F-102-08-04, F-117-08-06, F-13-09-03, 0.9 cmolc dm-3; H+Al = 3.7 cmolc dm-3; of chemical fertilizers applied to the F-158-08-01, F-158-08-02, F-18-09-03, CTC = 7.3 cmolc dm-3 and V = 49.3%. planting line. Thus, cultivars which F-183-08-01, F-21-09-07, F-22-08-01, For the conventional system: organic are more rustic and efficient in nutrient F-31-08-05, F-37-08-01, F-63-10-07, matter = 33.7 g dm-3; pH (H2O) = 5.2; uptake, or which are more tolerant to F-97-07-03, PCDINV10, PCDSE090 P (Mehlich) = 1.0 mg dm-3; K = 462.0 diseases, are recommended for the and control Agata (the most planted mg dm-3; Ca = 4.6 cmolc dm-3; Mg = organic system. cultivar in Brazil for fresh market) and 0.7 cmolc dm-3; H+Al = 6.2 cmolc dm-3; Asterix (the most planted in Brazil for CTC = 12.7 cmolc dm-3 and V = 51.0%. Potato productivity in organic system industrial purposes). Cultivation periods is generally lower than in conventional (from planting to harvest) were from The fertilizations in organic system system. Nevertheless, the higher value June 3, 2016 to October 7, 2016 and were done in planting furrows containing paid for organic tubers, coupled with a May 29, 2017 to October 2, 2017 for 28,750 kg ha-1 organic compost, milder requirement of the market for the organic cultivation and from May 18, according to the recommendation of good appearance and size of tubers, can 2016 to September 15, 2016 and May Couto et al. (2008) and 1,250 kg ha-1 maintain the profitability of the system. 15, 2017 to September 14, 2017 for of magnesian thermophosphate (2.0% Besides, using appropriate management conventional cultivation. The difference N, 10.0% P2O5, 7.0% K2O, 8.0% Ca technique, such as, application of between planting times and harvest and 1.0% Mg). For the conventional fertilizers and products which are considering conventional and organic system, fertilization was done using a allowed in organic system, provides a systems (about 15 days) was due to mixture of urea, superphosphate and satisfactory productivity, and also an operational need for scaling up the use potassium chloride, at doses of 190 kg acceptable product quality (Nazareno, of labor and machinery. ha-1 N, 420 kg ha-1 P2O5 and 210 kg ha-1 2009). K2O. Hilling up in both experiments was Plantings were carried out in the carried out about 40 days after planting. The most used potato cultivars in same areas, in each system, but in Weeds, pests and diseases control was Brazil are from Europe and they stand different plots in each year. Organic performed through manual weeding for out for its good tuber appearance (fresh cultivation area is isolated from the organic system and using metribuzin market) or suitability for processing, conventional one, by trees and shrubs herbicide at a dose of 480 g of active in the case of cultivars for industrial used as windbreaks. This area has been ingredient/ha applied 6 days after purposes. These cultivars were selected managed in the organic system for over planting in the conventional system. under weather and soil conditions, such 15 years. Before experiment installation, as photoperiod, soil acidity, temperature the area used in each year underwent The experiments were carried out and disease pressure highly contrastive fallow with spontaneous vegetation in a randomized blocks experimental to the conditions found in the potato composed, predominantly, of grasses design, with three replicates. Useful cultivating areas in Brazil. These for, at least, 10 years. area of the plot consisted of a row with differences make European cultivars 10 plants, spaced 0.80 m between lines less adapted to cultivation in Brasil, The potato seed of the first cycle of and 0.35 m between plants. requiring higher quantity of inputs in experiments (2016) consisted of type II order to achieve higher productivity After harvests, the following yield (Silva et al., 2014). traits were evaluated: total tuber mass, in kg (TTM), marketable tuber mass, in kg 54 Horticultura Brasileira 38 (1) January - March, 2020

Performance of advanced potato genotypes in organic and conventional production systems (MTM) and number of marketable tubers fast sprouting and showed marketable production system. For the conventional (NMT), considering as marketable, the tuber productivity about 50% lower in system, genotypes F158-08-01, F158- tubers showing a transverse diameter the second harvest. 08-02 and F183-08-01 were superior. above 45 mm. Genotypes F18-09-03, F21-09-07, In 2016 harvest, genotypes with F63-10-07, F97-07-03, PCDINV10 Data were standardized to production higher MTM were F158-08-01, F158- and PCDSE090 showed performance per hectare based on plant population 08-02 and F183-08-01. Also, genotypes similar to the most productive control quantified 50 to 60 days after planting F102-08-04, F18-09-03, F21-09-07, (Asterix). Comparing organic and in plots individually. Individual and F63-10-07, F97-07-03, PCDINV10 and conventional systems, most genotypes joint variance analyses were performed. PCDSE090 showed to be superior to showed better yields under conventional Then, analyses of variance and Scott- controls (Table 1). system, on average, about 75% more Knott average clustering (p≤0.05) using (Table 2); however, the most productive statistical software Genes (Cruz, 2013) In 2017 harvest, genotypes F158- genotypes, F158-08-01 and F158-08-02, were carried out. 08-01 and F158-08-02 were the most showed similar performance under the productive. These two genotypes two systems (Table 1). RESULTS AND DISCUSSION also maintained similar yield in both evaluated harvests and production Considering the number of Significant difference among systems. Genotypes F183-08-01, F31- marketable tubers, most genotypes, genotypes for all evaluated traits was 08-05, F63-10-07 and F97-07-03 also especially the most productive ones, had observed. We also verified significant presented results superior to controls fewer marketable-sized tubers in 2017, interaction between genotypes, years (Table 1). when seeds were kept for a longer time and production systems for all traits that in a cold chamber. Genotypes F158-08- measure marketable tuber productivity, Genotypes F158-08-01 and F158- 02 and F21-09-07 produced a greater i.e. marketable tuber mass (MTM) and 08-02 were superior to the others under quantity of marketable tubers in 2016, number of marketable tubers (NMT) organic system, considering marketable considering that genotype F158-08-02 (data not shown). For total tuber mass tuber mass. Genotypes F13-09-03, F-18- also showed greater quantity in 2017, (TTM), although a significant effect of 09-03, F-183-08-01, F-21-09-07, F31- not differing statistically from genotype the factor systems (data not shown) was 08-05, F63-10-07 and F97-07-03 also observed, no significant change in the outperformed the controls under this classification of genotypes in different years or systems was noticed (Table Table 1. Clustering of means of the evaluation of potato genotypes for total tuber mass 1). Variation coefficients were low (TTM) and marketable tuber mass (MTM), in Brasília-DF under organic and conventional (between 13.74% for TTM and 18.17% systems, 2016 and 2017 harvests. Brasília, Embrapa, 2019. for MTM), considering that yield traits are quantitative and, as a consequence, MTM (t ha-1) result in a greater environmental influence than the qualitative traits Genotypes TTM (t ha-1) Year System (Silva et al., 2016). F-102-08-04 26.16 B 2016 2017 Organic Conventional In relation to TTM, genotypes F-117-08-06 22.12 B 20.53 Ba 13.00 Cb 7.66 Cb 28.71 Ba F158-08-01, F158-08-02, F183-08-01, F-13-09-03 32.14 B 15.32 Ca 8.11 Db 6.65 Cb 17.45 Ca F21-09-07, F97-07-03 and PCDSE090 F-158-08-01 48.77 A 19.88 Ca 16.63 Ca 15.23 Bb 21.46 Ca were the most productive over the years F-158-08-02 52.93 A 39.88 Aa 37.37 Aa 37.55 Aa 39.69 Aa and cultivation systems, outperforming F-18-09-03 30.78 B 44.79 Aa 32.68 Aa 37.97 Aa 39.04 Aa even the controls (Table 1). F-183-08-01 45.31 A 27.83 Ba 15.60 Cb 13.45 Bb 30.86 Ba F-21-09-07 36.17 A 35.40 Aa 24.28 Bb 19.34 Bb 41.94 Aa In relation to MTM, which is F-22-08-01 17.26 B 27.78 Ba 16.69 Cb 14.44 Bb 30.84 Ba the most important trait, the average F-31-08-05 27.82 B 11.29 Da 10.48 Ca 10.32 Da production in 2016 (23.99 t ha-1) was F-37-08-01 16.46 B 14.31 Cb 9.55 Da 16.54 Ba 19.37 Ca higher than in 2017 (17.48 t ha-1). This F-63-10-07 31.14 B 8.75 Da 21.94 Ba 5.59 Cb 14.74 Ca might have been explained by the time F-97-07-03 37.33 A 22.39 Ba 10.59 Da 16.84 Bb 30.31 Ba the seeds remained in a cold chamber in Agata 20.08 B 27.55 Ba 23.81 Ba 18.48 Bb 32.61 Ba the second year, because the longer the Asterix 27.91 B 16.21 Ca 22.68 Ba 6.93 Cb 19.22 Ca seed tubers remain stored, the greater PCDINV10 29.05 B 17.49 Ca 8.97 Db 9.63 Cb 22.91 Ba their sprouting, which results in plants PCDSE090 36.76 A 29.42 Ba 13.79 Ca 11.50 Cb 23.98 Ba with a greater number of stems, greater 29.01 Ba 8.16 Db 11.81 Cb 31.43 Ba total number and smaller size of tubers 13.39 Cb in the subsequent harvest (Bisognin & Streck, 2009). This was evident Averages followed by same lowercase letters in line or same uppercase letters in column observing the cultivar Agata, which has belong to the same group based on Scott-Knott clustering test, 5% probability. Horticultura Brasileira 38 (1) January - March, 2020 55

CF Ragassi et al. F63-10-07. Genotypes F158-08-01 as late blight (Phytophthora infestans) organic and conventional system, and F158-08-02 presented the highest and early blight (Alternaria solani), respectively (Table 2). However, yields number of marketable tubers under tend to show a better performance close to 40 t ha-1 were obtained for organic system. Genotypes F158-08-02, under the organic system. In this study, the most productive genotypes in F21-09-07 and PCDSE090 showed the these diseases were not observed, both systems (Table 1). Rossi et al. greatest number of marketable tubers even under organic cultivation, which (2011) evaluated 18 potato genotypes under conventional system (Table 3). is a consequence of the adoption of in organic system in São Paulo State, preventive measures, in particular, considering as marketable those tubers According to Nazareno (2009), the cultivation in a less disease-prone with transversal diameter above 40 the organic cultivation differs from season. Then, we observed that the mm, and they verified productivity of the conventional in several aspects. disease tolerance factor did not represent marketable tubers ranging from 3.78 In organic system, low solubility a competitive advantage among the to 18.07 t ha-1. Those authors also fertilizer sources are used, such as studied genotypes. verified that tolerance to early blight organic composts or rocks (whereas was important, due to the occurrence in conventional cultivation, high doses The average yield of marketable of this disease, considering that cultivar of soluble fertilizers are applied to tubers considering the two years was Agata and, mainly, Asterix, were the the planting lines), and insecticides 15.30 t ha-1 and 26.75 t ha-1 under and fungicides commonly used in conventional system are not allowed for Table 2. Clustering of means of the evaluation of potato genotypes for marketable tuber mass use in the organic system. For pest and (MTM) and number of marketable tubers (NMT), evaluated in Brasília-DF under organic disease control, only natural chemical and conventional systems, 2016 and 2017 harvests. Brasília, Embrapa, 2019. and biological substances, extracts and organisms are allowed. Since fewer MTM (t ha-1) NMT ha-1/1000 products to control pests and diseases are allowed in organic cultivation, the System 2016 2017 use of tolerant or resistant cultivars is even more important. Thus, genotypes Organic 15.30 B 83.95 Ba 52.72 Bb that are more resistant to diseases such Conventional 26.75 A 206.55 Aa 119.21 Ab Averages followed by same lowercase letters in line or same uppercase letters in column belong to the same group based on Scott-Knott clustering test, 5% probability. Table 3. Clustering of means of the evaluation of potato genotypes for number of marketable most affected ones. Passos et al. (2017) tubers (NMT) per hectare/1000, evaluated in Brasília-DF under organic and conventional evaluated 8 potato cultivars under systems, 2016 and 2017 harvests. Brasília, Embrapa, 2019. organic system in three experiments in the Southern Brazil and verified, in Genotypes Year System average of the experiments, marketable Organic Conventional yield from 12 to 22.70 t ha-1. F-102-08-04 2016 2017 F-117-08-06 49.98 Cb 199.11 Ba Silva et al. (2017) evaluated 13 F-13-09-03 155.92 Ba 75.65 Bb 37.95 Cb 120.61 Ca advanced potato clones, and also the F-158-08-01 88.04 Bb 144.35 Ca cultivars Agata and Asterix, in organic F-158-08-02 103.54 Ca 48.58 Cb 117.15 Aa 130.08 Ca and conventional production systems F-18-09-03 141.23 Ab 257.46 Aa in 2016 in Brasília-DF, some of the F-183-08-01 144.14 Ba 88.21 Bb 72.10 Bb 180.21 Ba clones being the same evaluated herein. F-21-09-07 55.61 Cb 185.82 Ba The authors observed a great range in F-22-08-01 145.43 Ba 103.41 Bb 85.68 Bb 226.79 Aa marketable yields of different genotypes F-31-08-05 58.13 Ca 62.96 Ea in the organic system, from 3.50 to 38.75 F-37-08-01 222.60 Aa 169.28 Ab 76.87 Ba 104.64 Da t ha-1, with an average value of 13.50 t F-63-10-07 42.82 Cb 90.44 Da ha-1; whereas in an area nearby, under a F-97-07-03 171.10 Ba 78.07 Bb 87.32 Cb 181.10 Ba conventional system, the average yield Agata 80.79 Cb 187.49 Ba of marketable tubers was quite superior Asterix 141.86 Ba 84.31 Bb 42.04 Cb 136.04 Ca (21.66 t ha-1). In the Silva et al. (2017) PCDINV10 49.98 Cb 154.60 Ca study, clones F158-08-01 and F158- PCDSE090 208.00 Aa 97.91 Bb 67.39 Bb 190.65 Ba 08-02 showed good performance and 36.37 Cb 242.01 Aa they were superior to the other clones 64.37 Da 56.78 Ca in both production systems, considering that the clone F183-08-01 also grouped 78.96 Ca 102.24 Ba among the most productive ones in the conventional system. In relation to the 60.01 Da 69.05 Ca lower yield obtained in organic systems, 138.24 Ba 122.02 Aa 147.28 Ba 111.24 Bb 116.66 Ca 54.02 Cb 111.63 Ca 79.95 Ba 196.73 Aa 63.84 Cb 226.32 Aa 42.85 Cb Averages followed by same lowercase letters in line or same uppercase letters in column belong to the same group based on Scott-Knott clustering test, 5% probability. 56 Horticultura Brasileira 38 (1) January - March, 2020

Performance of advanced potato genotypes in organic and conventional production systems according to Nazareno (2009), it is also outperformed controls in organic January 30, 2019. compensated by the higher prices paid system. For conventional system, by the consumers of organic products. genotypes F158-08-01, F158-08-02 and NAZARENO, NRX. 2009. Produção orgânica de F183-08-01 were superior, genotypes batata - potencialidades e desafios. Londrina: Silva et al. (2018b) evaluated a F18-09-03, F21-09-07, F63-10-07, IAPAR. 249p. group of nine advanced potato clones, in F97-07-03, PCDINV10 and PCDSE090 Canoinhas-SC and Pelotas-RS (Southern showed similar or superior performance PASSOS, S; KAWAKAMI, J; NAZARENO, Brazil) and Brasília-DF (Brazilian comparing with the most productive NRX; SANTOS, KC; TAMANINI JUNIOR, Center-West) in a conventional control (Asterix). Genotypes F158-08- C. 2017. Produtividade de cultivares de batata cultivation system, the same results 01 and F158-08-02 were superior in both orgânica em região subtropical do Brasil. of this study for clones F21-09-07 systems and show potential to become Horticultura Brasileira 35: 628-633. and F183-08-01 being verified. The new recommended cultivars for both authors verified that clone F21-09-07 production systems. ROSSI, F; MELO, PCT; AZEVEDO FILHO, was superior to the others in relation JA; AMBROSANO, EJ; GUIRADO, N; to productivity and frying quality, the REFERENCES SCHAMMASS, EA; CAMARGO, LF. 2011. clone F183-08-01 being one of the Cultivares de batata para sistemas orgânicos most productive in Brasília-DF, though. BISOGNIN, DA; STRECK, NA. 2009. de produção. Horticultura Brasileira 29: In relation to marketable tuber mass Desenvolvimento e manejo das plantas para 372-376. in Brasília-DF, clones F21-09-07 and alta produtividade e qualidade da batata. F183-08-01 produced 28.59 t ha-1 and Itapetininga: ABBA. 27p. SILVA, GO; BORTOLETTO, AC; CARVALHO, 41.07 t ha-1, respectively, quite similar AD; PEREIRA,AS. 2018a. Effect of potassium to the present study (30.84 and 41.94 t COUTO, JR; RESENDE, FV; SOUZA, RB; sources on potato tuber yield and chip quality. ha-1, respectively, under conventional SAMINEZ, TCO. 2008. Instruções práticas Horticultura Brasileira 36: 395-398. production system). para produção de composto orgânico em pequenas propriedades. Brasília: Embrapa SILVA, GO; BORTOLETTO, AC; PONIJALEKI, Despite the lower average yield of Hortaliças, 8p. (Comunicado Técnico 53). R; MOGOR, AF; PEREIRA, AS. 2014. tubers in organic system, it was possible Desempenho de cultivares nacionais de batata to select genotypes with high productive CRUZ, CD. 2013. Genes; a software package para produtividade de tubérculos. Revista potential in this system, mainly F158- for analysis in experimental statistics and Ceres 61: 752-756. 08-01 and F158-08-02, with high quantitative genetics. Acta Scientiarum yield of marketable tubers, the values Agronomy 35: 271-276. SILVA, GO; CARVALHO ADF; PEREIRA in organic cultivation being almost AS; RAGASSI, CF; AZEVEDO FQ. 2017. equivalent to the conventional system. IBGE - Instituto Brasileiro de Geografia e Desempenho de clones avançados de batata Genotypes F102-08-04, F13-09-07, Estatística. 2019. Available at Levantamento para rendimento de tubérculos em quatro F-18-09-03, F-183-08-01, F-21-09-07, Sistemático da Produção Agrícola. Rio de ambientes. Agro@mbiente 11: 323-330. F31-08-05, F63-10-07 and F97-07-03 Janeiro: IBGE. <https://sidra.ibge.gov.br/ home/lspa>. Accessed January 20, 2019. SILVA, GO; PEREIRA AS; AZEVEDO FQ; CARVALHO ADF. 2016. Avaliação de clones FAOSTAT. 2015. Production quantities by country de batata para caracteres de rendimento e average 1993 - 2013. Available at <http:// qualidade de fritura. Revista Latinoamericana faostat3.fao.org/browse/Q/QC/E>. Accessed de la Papa 20: 37-44. SILVA, GO; PEREIRA, AS; CARVALHO, ADF; AZEVEDO, FQ. 2018b. Seleção genotípica de clones de batata para rendimento de tubérculos, aspecto vegetativo e qualidade de fritura. Revista Brasileira de Ciências Agrárias 13: e5534. Horticultura Brasileira 38 (1) January - March, 2020 57

Research MARQUES, DJ; MATHEUS FILHO, E; BIANCHINI, HC; VERONEZE JUNIOR, V; SANTOS, BR; CARLOS, LA; SILVA, EC. 2020. Tomato production in hydroponic system using different agrofilms as greenhouse cover. Horticultura Brasileira 38: 58-64. DOI - http://dx.doi.org/10.1590/S0102-053620200109 Tomato production in hydroponic system using different agrofilms as greenhouse cover Douglas José Marques 1ID; Edmur Matheus Filho 2ID; Hudson C Bianchini 2ID; Valdir Veroneze Junior 3ID; Breno Régis Santos 3ID; Lanamar de A Carlos 4ID; Ernani Clarete da Silva 4ID 1Universidade Federal de Uberlândia (UFU), Monte Carmelo-MG, Brasil; [email protected]; 2UNIFENAS, Alfenas-MG, Brasil; [email protected]; [email protected]; 3Universidade Federal de Alfenas (UNIFAL), Alfenas-MG, Brasil; [email protected]; [email protected]; 4Universidade Federal de São João del Rei (UFSJ), Sete Lagoas-MG, Brasil; [email protected]; [email protected] ABSTRACT RESUMO Protected cultivation has increased over the years. More studies Produção de tomate no sistema hidropônico usando diferentes on the benefits of using photoselective agrofilms are necessary. The agrofilmes para cobertura da casa de vegetação choice of material to cover the greenhouse is a decisive factor for crop development and production. The aim of this study was to evaluate O cultivo protegido tem aumento ao longo dos anos, havendo the effect of diffuser and blue-colored agrofilms on the production necessidade de ampliar as pesquisas que comprovem benefícios of different tomato cultivars of indeterminate growth habit under da utilização de agrofilmes fotosseletivos. A escolha do material NFT hydroponic system. A completely randomized design in a 2x3 para a cobertura da casa de vegetação é fator decisivo para o factorial scheme (two environments and three cultivars) was used: desenvolvimento da cultura e produção. O objetivo deste trabalho two agrofilm types (blue and diffuser) and 3 cultivars (Monterrey, foi avaliar o efeito dos agrofilmes de cor azul e o difusor na Arendell and Totalle). Each plot consisted of 30 plants per treatment, produção de diferentes cultivares de tomateiro de hábito de with four replicates. Commercial tomato seedlings of indeterminate crescimento indeterminado no sistema hidropônico-NFT. Utilizou- growth habit grafted on rootstock cultivar (Shincheonggang) were se o delineamento inteiramente casualizado em esquema fatorial used. During the experiment, the electrical conductivity, intensity 2x3 (dois ambientes e três cultivares): dois tipos de agrofilme (azul of radiation inside the greenhouse, gas exchange, soluble solids, e difusor) e 3 cultivares (Monterrey, Arendell e Totalle), sendo lycopene content, pH and fruit production were evaluated. We cada parcela constituída por 30 plantas por tratamento, com quatro concluded that the amount of radiation transmitted through the repetições. Utilizaram-se mudas comerciais de tomateiro de hábito diffuser favors an increase of about 18% in gas exchange, 12% in de crescimento indeterminado enxertadas em porta-enxerto cultivar lycopene content and 9.4% in tomato crop production. Shincheonggang. Foram avaliadas durante a pesquisa a condutividade elétrica, intensidade da radiação dentro da casa de vegetação, trocas gasosas, sólidos solúveis, teor de licopeno, pH e produção de frutos. Conclui-se com a pesquisa que a quantidade de radiação que passa pelo agrofilme difusor favorece um aumento em torno de 18% as trocas gasosas, 12% o teor de licopeno e 9,4% a produtividade da cultura do tomate. Keywords: Lycopersicon esculentum, lycopene, gas exchange, Palavras-chave: Lycopersicon esculentum, licopeno, trocas gasosas, radiação. radiation. Received on May 8, 2019; accepted on January 28, 2020 Tomato is one of the main vegetables for producing vegetables and cut flowers 2011). grown in Brazil. The Country ranks (Cobapla, 2018), considering that about the ninth position, 2.5% of production 10 thousand hectares are located in São In Brazil, protected cultivation area worldwide, being possible to increase Paulo State. Vegetable cultivation in has increased along the years, thus its production and commercialization in a protected environment is a booming more studies on the benefits of using the next decade (Dossa & Fucks, 2017). activity in Brazil; its great advantage photoselective agrofilms are necessary. is the off season production, allowing In Brazil, tomato is cultivated in greater regularization of supply and Using polyethylene cover on a approximately 22 thousand hectares of better product quality (Andrade et al., greenhouse interferes in microclimate protected environment and high tunnels and in radiation and energy balance, resulting in several benefits such 58 Horticultura Brasileira 38 (1) January - March, 2020

Tomato production in hydroponic system using different agrofilms as greenhouse cover as earliness, increase in production MATERIAL AND METHODS Cultural practices and phytosanitary and plant protection against weather management were carried out in the adversities (Cunha et al., 2002). The experiment was carried out in experiment, according to the crop’s a greenhouse, at Setor de Olericultura necessity. Plants were tutored using Agrofilms known as diffusers e Experimentação, Engenharia ribbons, one stem per plant, 35 days have in their composition additives Agronômica at UNIFENAS, Alfenas- after transplanting. Lateral sprouts were which control solar radiation, directly MG, from April 2 to October 2, 2018. eliminated from the 15th day of seedling related to the suitability of temperatures transplanting every week and defoliation (Sousa et al., 2002). According to Two greenhouses, arch-detached was performed from the beginning Papadakis (2000) the ideal material for type, 9-meter wide, 25-m long and of fruit ripening and top pruning was protected cultivation has to allow 100% 4.0 m ceiling height were used. performed above the tenth cluster. transmission of photosynthetically Each greenhouse was covered with Defoliation consists of the removal active radiation, with wavelengths blue-colored and diffusing agrofilm, of old leaves, without physiological ranging from 0.4 to 0.7 µm, which is respectively. activity, aiming to improve aeration, effectively used by plants during the increase photosynthetic efficiency photosynthesis process. The experimental design was and, mainly, reduce risks of incidence completely randomized in factorial of pests and diseases. Electrical Blue-colored agrofilm can select scheme 2x3. The treatments consisted conductivity, radiation intensity inside more favorable wavelengths for of two covered cultivation environments the greenhouse, gas exchange, soluble plants (PAR radiation), converting with different types of agrofilm solids, lycopene content, pH and fruit the light bands less used by plants (blue and diffuser) and three tomato production were evaluated. in photosynthetic process into more cultivars of indeterminate growth habit effective wavelengths, such as blue, red (Monterrey, Arendell and Totalle). Each At 90 days after seedling and extreme red. Thus, choosing the plot consisted of 30 plants, with four transplanting, the authors standardized material for covering a greenhouse is an replicates. 2.00-m height cultivation canopy inside extremely important factor to maintain the greenhouse, recording quality crop development, since it can alter Blue-colored agrofilm showed and quantity of radiation incidence solar radiation transmission into the the characteristics of photoconverter, (Espectrorradiômetro Luzchem, SPR- greenhouse, benefiting plants according microclimate control, light diffuser, anti- 4002, Ottawa, Canada) for one hour, to their demands (Guiselini et al., 2004). static, made with five layers, antivirus measuring the minimum radiation (390) and resistant to ultraviolet rays. The and maximum (790 nanometers). Tomato plants need maximal light diffuser agrofilm was photoselective, capture to maintain their entire vegetative antivirus, light diffuser, anti-static and In order to determine electrical apparatus and their ability to supply resistant to ultraviolet rays. conductivity, nutrient solution samples organs (sources and drains), especially were collected before and after fruits, which are key players in the We used commercial tomato renovation, every 2 weeks, until the feedback mechanism for their growth seedlings of indeterminate growth 19th cultivation week, using a digital (Gary et al., 2003). The luminosity habit (Monterrey, Arendell and Totalle) conductivity meter (Lutron, mod. CD- saturation point which establishes the on rootstock cultivar Shincheonggang. 4303). limiting level of photosynthetically Plants were conducted in 10 brickwork- active radiation up to the increase in patterned channels (cultivation Gas exchange, liquid photosynthesis, CO2 assimilation should be always channels), 20-cm wide, 25-cm high, transpiration, stomatal conductance, observed. Levels of photosynthetically 25-m long, 80-cm spacing and 3% slope. intercellular CO2 concentration, water active radiation below limit may The authors used 3000 L water volume use efficiency and instant carboxylation restrict photosynthesis and levels above for nutrient solution. The solution was efficiency were evaluated using an the limit may promote an excessive time-triggered every 15 minutes, and IRGA model LI-6400XT, (Li-Cor, temperature rise of the plant, with covered the channels for 15 minutes; Lincoln, Nebrasca, USA). Two plants negative consequences on transpiration then, the timer was turned off and the were randomly obtained from each and photosynthetic rate (Ferrari & Leal, process was restarted again after 15 plot, and sample unit was represented 2015). However, studies on alterations minutes. Timer was programmed to by the sixth leaf counting from the top, caused by photoselective agrofilms in apply the nutrient solution three times totally expanded and mature. Since it is a vegetable production are still scarce overnight. species which has compound leaves, the in Brazil. first three leaflets of each leaf were used The hydroponic solution was for measuring, totalizing six measures. The aim of this study was to evaluate managed weekly late afternoon (5 p.m.). Saturation irradiance was fixed at 850 the effect of blue-colored and diffuser At 8 a.m. electrical conductivity and pH μmol m-2 s-1, value defined by a light agrofilms on production of different (ideal values) were measured, 3.5 mS curve, value which induced maximum tomato cultivars of indeterminate cm and 6.5, respectively, completing the photosynthesis. Tomato is a C3 plant, growth habit under NFT hydroponic solution volume. The nutrient solution a plant which cyclic mechanism of system. used was recommended by Marques et enzymatic reactions converts CO2 into al. (2018). 59 Horticultura Brasileira 38 (1) January - March, 2020

DJ Marques et al. carbohydrates, through the reductive methodology proposed by Rodriguez- and red (675nm) wavelengths (Kämpf photosynthetic cycle (C3), generating Amaya (2001), which consists of et al., 2000). the 3-phosphoglycerate. That is why, extracting carotenoids using acetone the temperature of the IRGA camera was (P.A.) and quantifying these chemical We evaluated electrical conductivity controlled at 28ºC, since in C3 plants the substances using a spectrophotometry (CE) before (Figure 2A) and after maximum photosynthesis rate (TMF) at 470 nm. The results were expressed (Figure 2B) the preparation of a new is achieved in relatively low radiation in µg of lycopene per 100 grams fresh nutrient solution of tomato grown intensity, causing no destruction or mass. under the two types of agrofilm. damage to the photosynthetic apparatus. Throughout cultivation, CE was higher Measurements were carried out on a The obtained results were submitted in the treatment where the blue-colored 6-cm2 leaf area. to variance analysis and averages agrofilm was used (Figure 2A). This submitted to Scott-Knott test, using result may be related to the fact that Ten harvests were performed during SISVAR software according to the blue-colored agrofilm provided the experiment, as tomato fruits were theories advocated by Ferreira (2011). very varied wavelengths, which made becoming ripe. After harvests, fruits Afterwards, in order to compare the tomato plants absorb lower quantity of were separated and classified (MAPA, results, the authors performed statistical nutrient solution, resulting in higher CE. 1995). Then, number of fruits and joint analysis of the data obtained in After changing the nutrient solution, no production of marketable fruits were each greenhouse. significant differences were observed quantified (average 30 plants per plot). in CE throughout the evaluated weeks RESULTS AND DISCUSSION (Figure 2B). Tomato fruits were stored in thermal boxes and taken under refrigeration The highest radiation intensity was Cultivars Arendell and Monterrey to Laboratório de Conservação de obtained using the blue-colored agrofilm showed higher stomatal conductance, Alimentos of Universidade Federal de in a wavelength from 454 to 566 nm liquid photosynthesis and transpiration São João Del-Rei, Sete Lagoas-MG, and using the diffusing agrofilm in a rates (Figures 3A, B and C) for being prepared and evaluated. All wavelength from 470 to 630 nm (Figure diffusing agrofilm; for cv. Totalle the analyses were performed in triplicates. 1). The form of electromagnetic waves highest stomatal conductance, liquid We determined pH using a potentiometer in the blue agrofilm varied to blue (470 photosynthesis and transpiration rates (AOAC, 2012) with the aid of a Tekna nm), green (490 nm) and yellow (585 were found using blue-colored agrofilm digital pH meter model T-1000, by direct nm), reducing to orange, (585 - 640 nm) (Figures 3A, B and C). Due to higher immersion of the electrode in the crushed and red (640 - 740 nm). For the diffuser, radiation intensity caused by the blue and homogenized fresh fruit extract. less variation for the wavelengths of agrofilm, cvs. Arendell and Monterrey Total soluble solid contents (°Brix) were blue and orange to red was noticed. were probably submitted to some type determined placing drops of the fresh In photosynthetically active radiation, of photoinhibition which reduced fruit extract, crushed, homogenized light absorption varies depending on the stomatal conductance and transpiration, and filtered, on the prism of a Reichert physiological process to blue (435nm) according to observed by Ferraz et al. r2MINI digital refractometer. Lycopene (2012). These results are in accordance content was determined according to the with the ones found in this experiment (Figures 3A, B, C). According to 80000 Blue Diffuser Lima et al. (2010), stomatal behavior 70000Radiation intensity (W/m2) determines the transpiration demand 60000 390 by controlling the loss of H2O from the 50000 406 leaves to the environment, in the form 40000 422 of water vapor. Liquid photosynthesis is 30000 438 an indicator of carbon assimilation rate 20000 454 (Popov et al., 2003), considering that 10000 470 agricultural productivity is influenced 486 by morphological and physiological 0 502 traits of photosynthetic organs, such as 518 leaves, and of consuming organs of the 534 photoassimilates, known as drains. 550 566 The highest intercellular CO2 582 concentration (Ci) in tomato leaves 598 was observed with the use of blue 614 agrofilm, for cvs. Arendell, Monterrey 630 and Totalle (Figure 4A). The highest 646 instant carboxylation efficiency was 662 found in cvs. Arendell and Monterrey, 678 using diffusing agrofilm (Figure 4B). 694 710 726 742 758 774 790 Wavelengths (nm) Figure 1. Radiation intensity (W/m2) of blue-colored and diffusing agrofilms in relation to different wavelengths (nm). Alfenas, UNIFENAS, 2018. 60 Horticultura Brasileira 38 (1) January - March, 2020

Tomato production in hydroponic system using different agrofilms as greenhouse cover 2.5 Blue Diffuser 2.5 Blue Diffuser A B 2.0 2.0 aa aa aa aa aa 1.5 1.5 aa EC (mS cm-1) aa aa EC (mS cm-1) 1.0 1.0 a a a a a b a a 0.5 0.5 a a ab ba bab Agrofilme azul b b a b a b 0.0 Difusor b 2 4 6 8 10 12 14 16 18 20 Weeks after transplant 0.0 2 4 6 8 10 12 14 16 18 20 Weeks after transplant Figure 2. Electrical conductivity evaluated before (A) and after renewing the nutrient solution (B) in tomato crop in relation to the two agrofilms. Alfenas, UNIFENAS, 2018. 0.010 Blue Diffuser 40 Blue Diffuser 1.2 C Blue Diffuser A a b B ab 1.0 a a 0.8 b 0.008 a ab 30 b b 0.6 a a b 0.006 (mmol H2O m-2 s-1)bb a (µmol de CO2 m-2 s-1) b (mmol H2O m-2 s-1) 20 0.004 0.002 10 0.4 0.2 0.000 Arendell Monterrey Totalle 0 0.0 Tomato cultivars Arendell Monterrey Totalle Arendell Monterrey Totalle Tomato cultivars Tomato cultivars Figure 3. Stomatal conductance (A), liquid photosynthesis (B) and transpiration (C) of three tomato cultivars in relation to different agrofilms. Alfenas, UNIFENAS, 2018. The blue agrofilm was superior when However, an increase in CO2 content agrofilm used to cover the greenhouses. comparing with the diffusing film for in the greenhouse may cause reduction No significant difference was observed water use efficiency (EUA) (Figure in stomatal conductance (Shimono et for cv. Totalle, whereas cvs. Arendell 4C). According to Jadoski et al. (2005), al., 2010). Low stomatal conductance, and Monterrey showed the highest an increase in CO2 assimilation rate is observed in high CO2 concentrations productions when diffusing agrofilm related to higher CO2 concentration causes less transpiration, considering was used (Figure 5A). This fact was found in the leaves, which may be related that stomatal closing and consequent due to a better light distribution by the to stomatal closing in response to abiotic reduction of normal flow of CO2 towards diffusing agrofilm, which maximizes stresses. Daley et al. (1989) reported carboxylation site are one of the main the use of high light intensities. Also, that a reduced stomatal conductance light quality strongly affects plant is able to limit CO2 retention rate responsible for photosynthesis reduction growth: the light of wavelength in and, consequently, intercellular CO2 (Bosco et al., 2009). green zone, causes greater elongation concentration will decrease, due to CO2 of stems and leaves; wavelengths consumption by photosynthetic activity. In relation to fruit production, the mostly in red and blue zones reduce authors observed different responses of the genotypes in relation to the type of Horticultura Brasileira 38 (1) January - March, 2020 61

DJ Marques et al. Figure 4. Intercellular CO2 concentration (A), instant carboxylation efficiency (B), water use efficiency (C) in relation to different agrofilms and tomato cultivars. Alfenas, UNIFENAS, 2018. Figure 5. Tomato production (A) and fruits (B) in relation to different agrofilms and tomato tomato is a C3 plant, where maximum cultivars. Alfenas, UNIFENAS, 2018. rate of photosynthesis is achieved at relatively low radiation intensity. Fruit plant etiolation (Pinho et al., 2012), with the use of the blue agrofilm may pH did not range significantly with decreasing photoinhibition (Li et al., be related to radiation intensity (Figure the use of agrofilms, for the studied 2012). The lower and intermediate 1) in the green zone, of the visible light cultivars (Figure 6A). Soluble solid leaves are favored by the use of diffused spectrum, which may have caused contents in fruits, expressed in °Brix, light, significantly improving their greater elongation of stems and leaves, was higher for cultivars Monterrey and photosynthetic rates (Dueck et al., consequently reducing fruit production. Totalle, regardless of the cultivation 2012). The lowest production observed This may also be related to the fact that environment. For cultivar Arendell, the blue agrofilm provided higher soluble solid content in relation to the diffusing agrofilm (Figure 6B). Minimum contents observed in tomato juice should be pH 4.3 and soluble solid content of 5oBrix, at 20oC temperature (MAPA, 2018). According to Schwarz et al. (2013), fruits showing soluble solid content above 3°Brix can be commercialized in fresh fruit markets. Lycopene content of the fruits (Figure 6C) was higher when the cultivars were grown in an environment covered with diffusing agrofilm. Considering qualitative trait, this is an important result, since lycopene belongs to the carotenoid family, which also includes beta-caroten, found in some fruits and vegetables, giving them a red color, and being usually present in large quantities in tomato fruits. Several studies point out the efficiency of lycopene as an antioxidant, inclusive relating this function to cancer prevention, especially prostate cancer (Soares & Farias, 2012). The authors concluded that the amount of radiation which passes through the diffusing agrofilm favors an increase, of around 18%, in gas exchange, 12% in the lycopene content 62 Horticultura Brasileira 38 (1) January - March, 2020

Tomato production in hydroponic system using different agrofilms as greenhouse cover Figure 6. pH quantification (A), soluble solid content expressed in oBrix (B) and lycopene content in fruits (C) of three tomato cultivars, grown under different agrofilms. Alfenas, UNIFENAS, 2018. and 9.4% in tomato production. DOSSA, D; FUCHS, F. 2017. Tomate: análise LI, T; HEUVELINK, E; DUECK, TA; técnico-econômica e os principais indicadores MARCELIS, LFM. 2012. Understanding ACKNOWLEDGEMENTS da produção nos mercados mundial, brasileiro how diffuse light increases yield in tomato. e paranaense. Paraná: CEASA. 50p. (Boletim ISHS Proc. 7th International Symposium on The authors thank to Foundation Técnico) Light in Horticultural Systems, Leuven. Book for Research Support of Minas Gerais of Abstracts. 98p. (FAPEMIG, Brazil) for the financial DUECK, T; JANSE, J; Li, T; KEMPKES, F; support for this study and the national EVELEENS, B. 2012. Influence of diffuse LIMA, MA; BEZERRA, MA; GOMES, EF; council for scientific and technological glass on the growth and production of tomato. PINTO, CM; ENÉAS, JF. 2010. Trocas development (CNPq, Brazil) for the gasosas em folhas de sol e sombreadas de scholarships granted for the first author. Acta Horticulturae 958: 75-82. cajueiro anão em diferentes regimes hídricos. Revista Ciência Agronômica 41: 654-663. REFERENCES FERRAZ, RLS; MELO, AS; SUASSUNA, JF; BRITO, MEB; FERNANDES, PD; MAPA. 2018. Instrução Normativa Nº 37, de ANDRADE, WJS; FARIAS JÚNIOR, M; NUNES JÚNIOR, ES. 2012. Trocas gasosas 1º de Outubro de 2018. Available http:// SOUSA, MA; ROCHA, AC. 2011. Utilização e eficiência fotossintética em ecótipos de www.in.gov.br/materia/-/asset_publisher/ de diferentes filmes plásticos como cobertura feijoeiro cultivados no semiárido. Revista Kujrw0TZC2Mb/content/id/44304943/do1- de abrigos para cultivo protegido. Acta Pesquisa Tropical 42: 181-188. 2018-10-08-instrucao-normativa-n-37-de-1- Scientiarum Agronomy 33: 437-443. de-outubro-de-2018-44304612 FERRARI, DL; LEAL, PAM. 2015. Uso de tela AOAC - Association of Official Analytical termorrefletora em ambientes protegidos para MAPA. 1995. Portaria Nº 553, de 30 de agosto Chemistry. 2012. Official methods of analysis cultivo do tomateiro. Engenharia Agrícola de 1995. available http://sistemasweb. of the Association of Official Analytical 35: 180-191. agricultura.gov.br/sislegis/action/detalhaAto. Chemistry, Gaithersburg, Maryland. 3000p. do?method=visualizarAtoPortalMapa&cha FERREIRA, D. 2011. Sisvar: um sistema ve=1920192566 BOSCO, MRO; OLIVEIRA, AB; HERNANDEZ, computacional de análise estatística. Ciência FFF; LACERDA, CF. 2009. Efeito do NaCl Agrotecnologia 35:1039-1042. MARQUES, DJ; LUZ, FDV; BARROSO, sobre o crescimento, fotossíntese e relações RWF; BIANCHINI, HC. 2018. Software for hídricas de plantas de berinjela. Revista Ceres GARY, C; BALDET, P; BERTIN, N; DEVAUX, calculation of nutrient solution for fruits and 56: 296-302. C; TCHAMITCHIAN, M; RAYMOND, P. leafy vegetables in NFT hydroponic system. 2003. Time-course of tomato whole-plant In: Md. Asaduzzaman, PhD/Toshiki Asao COBAPLA. 2018. 10 de novembro. Guia respiration and fruit and stem growth during (org). Potassium - Improvement of quality Brasileiro de Plasticultura. Available http:// prolonged darkness in relation to carbohydrate in fruits and vegetables through hydroponic cobapla.com.br/index.php/guia-brasileiro-de- reserves. Annals of Botany 91: 429-438. nutrient management. 1st ed. Rijeka, Croatia: plasticultura. Accessed November 10, 2018. In TechOpen 1: 20-34. GUISELINI, C; SENTELHAS, PC; OLIVEIRA, CUNHA, AR; ESCOBEDO, JF; KLOSOWSKI, RC. 2004. Uso de malhas e sombreamento em PAPADAKIS, G. 2000. Radiometric and thermal ES. 2002. Estimativa do fluxo de calor ambiente protegido II: Efeito sobre a radiação properties of, and testing methods for, latente pelo balanço de energia em cultivo solar global e a fotossinteticamente ativa no greenhouse covering materials. Journal of protegido de pimentão. Pesquisa Agropecuária crescimento e produção da cultura de pimentão. Agricultural Engineering Research 77: 7-38. Brasileira 37: 735-743. Revista Brasileira de Agrometeorologia 11: 15-26. POPOV, EG; TALANOV, AV; KURETS, VK; DALEY, PF; RASCHKE, K; BALL, JY; BERRY, DROZDOV, SN. 2003. Effect of temperature JA. 1989. Topography of photosynthetic JADOSKI, SO; KLAR, AE; SALVADOR, ED. on diurnal changes in CO2 Exchange in intact activity of leaves obtained from video images 2005. Relações hídricas e fisiológicas em cucumber plants. Russian Journal of Plant of chlorophyll fluorescence. Plant Physiology plantas de pimentão ao longo de um dia. Physiology 50: 178- 182. 90: 1233-1238. Ambiência 1: 1-19. RODRIGUEZ-AMAYA, DB. 2001. A Guide to KÄMPF, AN; CRUZ, FZ; COSTA, DA; HESSE, Carotenoid Analysis in Foods. ILSI Human HH; VIELMO, HA; SILVA, L; PARADECA, Nutrition Institute. One Thomas Circle, NW, MRAM; SCHNEIDER, PS; BASTOS, Washington DC, 20005-5802, 64p. RM. 2000. Produção comercial de plantas ornamentais. 89p. SCHWARZ, K; RESENDE, JTV; PRECZENHAK, AP; PAULA, JT; FARIA, MV; DIAS, DM. PINHO, P; JOKINEN, K; HALONEN, L. 2012. 2013. Desempenho agronômico e qualidade Horticultural lighting - present and future físico-química de híbridos de tomateiro em challenges. Lighting Research and Technology 44: 427-437. Horticultura Brasileira 38 (1) January - March, 2020 63

DJ Marques et al. cultivo rasteiro. Horticultura Brasileira 31: Photosynthetica 48: 530. ESCOBEDO, JF; GALVANI, E. 2002. 410-418. Alterações da temperatura e umidade relativa SOARES AP; FARIAS LM. 2012. Efeito do do ar em ambiente protegido com cobertura de SHIMONO, H; SUZUKI, K; AOKI, K. 2010. Licopeno do tomate na prevenção do câncer polietileno difusor de luz. Revista Brasileira Effect of panicle removal on photosynthetic de próstata. Revista Interdisciplinar 5: 50-54. de Agrometeorologia 10: 1-9. acclimation under elevated CO2 in rice. SOUSA, JW; MARTINS, D; CUNHA, AR; 64 Horticultura Brasileira 38 (1) January - March, 2020

Research COMETTI, NN; SILVA, JV; ZONTA, E; CESSA, RMA. 2020. Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels. Horticultura Brasileira 38: 65-70, DOI - http://dx.doi.org/10.1590/S0102-053620200110 Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels Nilton Nélio Cometti 1ID; Josimar V da Silva 2ID; Everaldo Zonta 3ID; Raphael MA Cessa 4ID 1Instituto Federal de Brasília (IFB), Campus Planaltina, Brasília-DF, Brasil; [email protected]; 2Instituto Federal de Brasília (IFB), Campus São Sebastião, Brasília-DF, Brasil; [email protected]; 3Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica- RJ, Brasil; [email protected]; 4Instituto Federal de Brasília (IFB), Campus Planaltina, Brasília-DF, Brasil; [email protected] ABSTRACT RESUMO Protected cultivation has grown in Brazil. Generally, greenhouses Avaliação do fluxo de fótons fotossintéticos no cultivo de alface are covered with transparent plastic film and shading screen. The em diferentes níveis de sombreamento plastic, over time, loses its transparency due to pollution residues, dust and other debris. The loss of transparency reduces lightness, O cultivo protegido tem crescido no Brasil. Geralmente, as estufas photosynthesis and leads to losses of productivity and product quality. utilizam plástico transparente e tela de sombreamento na cobertura. A The losses are not always detectable by the farmer. Additionally, cobertura de plástico, com o passar do tempo, perde a transparência internal shading screens are used to reduce heating transmission to por adquirir resíduos de poluição, poeira e outros detritos. A perda de the ground. The objective of this study was to evaluate the impact of transparência reduz a luminosidade, a fotossíntese e acarreta a perda shading on lettuce crop productivity and to determine the optimum de produtividade e de qualidade dos produtos. O objetivo do trabalho shading to reach the highest productivity. Plots were set up inside and foi estudar o impacto do sombreamento sobre a produtividade da outside the greenhouse, with four shading levels with black screens cultura da alface e determinar o sombreamento ótimo para alcançar (0, 35, 50 and 75%). The treatments were converted to real shading o máximo de produtividade. Foram montadas parcelas dentro e fora from the photosynthetic photon flux measurement. The results of da estufa, com quatro sombreamentos com telas pretas (0, 35, 50 e fresh and dry phytomass were treated and analyzed by regression as a 75%). Os tratamentos foram convertidos em sombreamento real a function of the real shading. In ambient conditions of photosynthetic partir da medição de fluxo de fótons fotossintéticos transmitidos. photon fluxes around 1000 μmol m-2 s-1, reaching up to 2000 μmol m-2 Os resultados de fitomassa fresca e seca foram tratados e analisados s-1 at some hours of the day, typical of tropical environment, lettuce por regressão em função do sombreamento medido. Em condições may support a shading of up to 50% without risk of productivity ambientais de fluxo de fótons fotossintéticos em torno de 1000 µmol reduction; under these conditions, shading between 20 and 35% is m-2 s-1, alcançando até 2000 µmol m-2 s-1 em algumas horas do dia, beneficial, and can guarantee its maximum productivity in lettuce típico de ambiente tropical, a cultura da alface pode suportar um cultivation. It is recommended that the lettuce producer in protected sombreamento de até 50% sem risco de redução da produtividade. cultivation monitors the shelf life of the plastic, avoiding that the Sombreamentos entre 20 e 35%, nessas condições, são benéficos, shading exceeds 50%. In order to compare shading experiments, one podendo garantir o máximo de sua produtividade. Recomenda-se should use the incident photon flux (FFI) for the whole crop cycle, ao produtor de alface em cultivo protegido monitorar a vida útil do indicating the minimum limit value of FFI = 600 mol m-2 cycle-1 for plástico, evitando que o sombreamento ultrapasse 50%. Para fins de the crispy lettuce at an average temperature close to 21oC. comparação entre experimentos com sombreamento, propõe-se que seja utilizado o fluxo de fótons incidentes (FFI) para todo o ciclo da cultura, indicando o valor limite mínimo de FFI = 600 mol m-2 ciclo-1 para a alface crespa em temperatura média próxima a 21oC. Keywords: Lactuca sativa, plastic film, crop protection, light. Palavras-chave: Lactuca sativa, filme plástico, cultivo protegido, luminosidade. Received on May 6, 2019; accepted on February 22, 2020 Much of Brazil’s vegetable photoassimilates. However, when solar photorespiration can increase, thus production comes from protected radiation is excessively high, there is reducing liquid photosynthesis (Taiz & cultivation, which grows rapidly. The an increase in the transpiratory rate of Zeiger, 2013). Greenhouses are generally crop production is directly related the plant, causing stomatal closure and covered with transparent plastic film and to the photosynthetic activity and, reduction of photosynthesis (Poljakoff- shading screen. The plastic film loses its consequently, to the accumulation of Mayber & Gale, 2012). In addition, transparency over time due to pollution Horticultura Brasileira 38 (1) January - March, 2020 65

NN Cometti et al. residues, dust and other debris, and Degrees-Day concept, is the simplest entire treatment portion, both inside and deteriorates with sunlight exposure. The means of productivity comparability outside the greenhouse. The greenhouse, loss of transparency reduces lightness, as a function of the difference between three meters high, was covered with photosynthesis and leads to losses the average temperature and the basal transparent plastic with anti-UV of productivity and product quality, temperature of the crop, below which additive, 100 μm thick, and three years increasing economic losses. These the crop stops growing (Araújo et al., old. In order to avoid differences in losses are not always detectable by the 2010). temperatures within treatments, the farmer. In addition to the use of clear protective screen was removed on the plastic for crop protection, shading In order to assist the producer sides of the greenhouse. The average screens are commonly used to reduce in protected cultivation, our group temperature observed in the treatments irradiance and temperature within developed a mobile application, called was 21oC with a maximum variation of the greenhouses, thus increasing the “Estufa Inteligente” which allows, 1oC between treatments accompanied by productivity of the protected crops with relative precision, to determine a set of DS18B20 sensors connected in (Santosh et al., 2017; Lemos Neto et the percentage of greenhouse shading a datalogger built with Arduino MEGA al., 2017). Costa et al. (2011) did not indicating whether it is still suitable 2560 board (Arduino, 2017). observe significant differences in the for the crop (Silva & Cometti, 2017). arugula productivity in treatments In this case, one should know the ideal After the transplanting of the with shading up to 40%, but there was shading pattern for the crop as well as seedlings, the photosynthetic photon an improvement in productivity with the shading limit so that there is no loss flux (PPF) measurement was made three shading of 50%. Seabra et al. (2009) of productivity in order to properly feed times a day, close to 9:00 a.m., 12:00 found similar data for lettuce in tropical data into the application. a.m. and 15:00 p.m., always recording environment with high temperatures. In PPF, date, and time. We used a portable this case, the productivity was higher The objective of this study was to radiometer QMSW brand Apogee when shading was close to 50%, and evaluate the impact of shading on lettuce Instruments® for these measurements. crops were favored with a specific crop productivity and to determine The PPF readings were adjusted in type of reflective screen, which also the optimum shade for maximum quadratic curves. These curves were promoted the reduction of temperature productivity. integrated to total the mol volume of by 10 to 20%. Bezerra Neto et al. (2005) photons incident in the experiment for showed that the use of a polypropylene MATERIAL AND METHODS a period of 60 days for 12 hours a day. screen reduces the direct incidence of solar rays, increasing the photosynthesis Aresearch was carried out at Campus The plants were collected 35 days and reducing lettuce respiration due Planaltina, Instituto Federal de Brasilia, after transplanting when the plots to the favorable conditions, which Distrito Federal, Brazil (15°39’24”S, with larger plants were ready for increased accumulated dry matter. 47°41’50”W, 969 m altitude). The commercialization. At harvest, the tropical climate with dry winter and plants were weighed into the fresh On one hand, the fact that the farmer climate classification is Aw according phytomass and taken to the dehydrator does not have scientific knowledge on to Köppen, and the average temperature to measure the dry mass. the subject makes him unaware that is 21.1°C. shading can be at an excessive level; The calculation of the thermal sum, this way, he does not know the occasion The research was set during the in degrees day, was made based in to change the greenhouse plastic cover. period of April to May 2017 with equation 1: By the other hand, he does not have crisp lettuce cultivar Wanda. Two beds simple and cheap mechanisms to make containing the plots were cultivated, one (1) the decision to change the greenhouse inside and other outside the greenhouse. cover safely. This decision is usually Both were conducted under the same where DD= cumulative day degree; subjective, due to common sense, and conditions of irrigation, fertilization and Taveg= average air temperature (ºC); can be both early and late, both leading cultural treatment. and Tb= base temperature, which for to economic losses. In order to avoid this experiment were considered 10.0ºC, further losses in productivity, the plastic The experimental design, in blocks, and n= number of days at harvest cover is replaced every two years, but it had two environments, inside and outside (Araújo et al., 2010). can also cause financial loss by the early the greenhouse, four shading levels (0, replacing, because the plastic could still 35, 50 and 75%) and three replications. Data were analyzed on Microsoft have some useful time. Each plot was composed of 1.0 m2, with Office Excel and plotted in charts on 16 plants spaced 25x25 cm. Only the four Sigmaplot® in which the regression In addition to the effect of light on central plants of the bed were collected curves were elaborated. growth, it is critical to consider the for the phytomass measurement. The temperature that significantly affects others were discarded as border. The RESULTS AND DISCUSSION growth (Frantz et al., 2004). The thermal shading was done with plastic screens accumulation, consolidated in the of different meshes, placed on supports The treatments used in the experiment at 0.7 m from the ground covering the with photosynthetic photon fluxes (PPF) 66 are shown in Figure 1 (A). The error bars have large amplitude, especially in Horticultura Brasileira 38 (1) January - March, 2020

Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels treatments with lower shading (external Figure 3A, and the dried phytomass yields are above the lower limit of the cultivation, 0 and 35%) because they in Figure 3B. In both variables there 95% confidence interval indicated in contain data collected at different times was a sharp fall up to 60% of shading, Figure 3 by the dotted curves. (near 9:00, 12:00 and 15:00). The PPF indicating in general terms that the readings on these moments allowed us lettuce would not support such shading The obtained data show that there to calculate the actual shading as shown without loss of productivity. The is a great plasticity in the adaptation of in Figure 1B. These actual (measured) maximum fresh phytomass production lettuce plants to the photosynthetically shading treatments were used for calculated from the second degree active radiation. In this experiment, regression and shading effect analysis. polynomial was 186.5 g plant-1, with the 0% treatment (full sunlight), the From now on the term shading will 23.6% shading. Calculating a loss PPF average was 986±544 μmol m-2 be used for the actual (real) shading as high as 10% in fresh phytomass s-1, depending on the time during the calculated from the PPF readings. production, 167.8 g plant-1 would be day. In treatments with shading, results obtained with 48% actual shading show that productivity was maintained The PPF readings throughout the (dashed line cutting the “x” axis). The until the treatment with 50% of actual day were adjusted in polynomial curves maximum dry mass calculated from the shading, ie, PPF= 436±255 μmol m-2 s-1 shown in Figure 2, indicating the greater second degree polynomial fit was 16.8 g (Figure 1B, treatment 0%). Therefore, amplitude of the flux of photosynthetic plant-1, with 28% shading. Assuming a productivity can be maintained with an photons throughout the day in the reduction of up to 10% in dry biomass, average PPF variation of approximately treatments with less or no shading, 15.1 g plant-1, would be obtained with 450 to 1000 μmol m-2 s-1. C3 plants, especially 0 and 35% in the outside of 58% shading. In both variables, fresh which include lettuce, have a saturated the greenhouse. and dry biomass, with shading of 48 and photon acceptor system usually above 58%, respectively, aiming to guarantee 500 μmol m-2 s-1, well stated by Taiz The fresh phytomass production as a maximum of 10% productivity loss, & Zeiger (2013); this explains why a function of the PPF reduction by the there is “surplus” light for plants such actual (measured) shading is shown in as lettuce in the tropical environment. The maximum phytomass productivity Figure 1. Photosynthetic photon flux (PPF) in different shading levels with black screen. reached between 20 and 35% shading The inside area of the greenhouse had additional shading of the transparent plastic. A= PPF (for fresh and dry phytomass) shown variation as a function of applied treatments; B= PPF variation as a function of measured in Figure 3 corroborates the premise of actual shading. Error bars show PPF measurements throughout the day. Planaltina, IFB, 2017. the reduction of liquid photosynthesis in C3 plants subjected to high radiance and high temperature (Mondal et al., 2016), which occurs in a tropical environment in full sunlight as observed in the 0% shading treatment of this experiment. Many C3 species are facultative sun plants and adapted to shading, producing morphological and photosynthetic characteristics similar to shaded plants. They reduce their rate of respiration, reduce the photosynthetic rate, and they present saturation of the photosynthesis in low irradiance. These plants develop the ability to grow in the shade, but their growth is slow as can be observed in treatments with shading above 50%. In a study with arugula, Costa et al. (2011) did not observe significant differences in productivity within treatments with shading up to 40%, but favored with shading of 50%. Seabra et al. (2009) found similar data for lettuce on tropical environment under high temperature favoring shade productivity close to 50% along with a specific type of reflective screen, which promoted the reduction of temperature by 10 to 20%; this demonstrates that there is actually Horticultura Brasileira 38 (1) January - March, 2020 67

NN Cometti et al. surplus light in the tropical environment, does not reach critical levels, in this reduction is not easily noticeable on the and that the use of some shading may case, 50% shading. In our experiment, field because it is measurable only with even be beneficial. Excessive shading, the greenhouse in which the study was empirical experiments that can make however, can lead to an abrupt reduction based on (which is similar to those found rigid statistical comparisons, which rural in productivity. In the present study, in the surrounding region) already had producers are not able to do. Even so, shading above 60% caused productivity a shading of 64% leading to a reduction monitoring the transparency conditions loss of up to 32% every 10% increase of 35% in phytomass production in of the plastic greenhouse cover is in shading. Therefore, one should keep relation to the optimum production critical, and a simple and inexpensive the shading under control so that it calculated by the adjustment. This apparatus is required by the producer such as a mobile app that can express Figure 2. Variation of the photosynthetic photon flux throughout the day in different shading the shading of the greenhouse cover. levels with black screen. Planaltina, IFB, 2017. The correlation between actual Figure 3. Effect of shading on lettuce phytomass production. Dotted lines indicate 95% shading and incident photosynthetic confidence interval. Planaltina, IFB, 2017. photons (IPP) throughout the experiment was fit in the first order equation: “y = 1352-13.7 * x”, with R2 = 0.99 p<1%. It shows how the incident radiation curves of Figure 2 represent the reality of the incidence of photosynthetically active radiation since its integration returns the volume of incident photons perfectly correlated with real shadings. The integration of the incident photon curve is important to establish the shading utilization methodology in experiments since many results presented may be unfeasible considering the use of apparent shading percentages, which were simply originated from values announced for commercial meshes. A commercial shading screen of 50% does not necessarily represent an actual shading of 50%; therefore, results such as of Guerra et al. (2017), who found an increase in lettuce productivity in a 50% shading-screen environment as a result of increased photosynthetic activity, became difficult to be introduced on other environments due to lack of a comparative basis since there is no indication of PPF measurements that allow the identification of the actual shading even if the importance of absolute work results remains preserved. In order to assist the direct measurement of the shading percentage when there is no photosynthetic photon sensor available, we suggest the use of the light sensor of the cell phone, achieving this way a reasonable accuracy at field level as can be observed in the mobile app “Estufa Inteligente (Smart Greenhouse)”; this app is available at the Google Play® store, developed by scientists of the Instituto Federal de Brasilia (Silva & Cometti, 2017). 68 Horticultura Brasileira 38 (1) January - March, 2020

Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels Table 1. Photosynthetic photon flux (PPF), fresh and dry phytomass, incident photosynthetic photons (IPP), and photosynthetic photon efficiency (PPE) of lettuce as a function of shading with black plastic screen. Planaltina, IFB, 2017. Actual PPF Fresh Dry IPP PPE (mol m-2 cycle-1) (gms mol photon-1) shading (%) (µmol m-2 s-1) phytomass phytomass Curve equation (g plant-1) 0.0 986.0±544.1 171.5±25.9 15.4±1.9 y = -44531x2 + 45081x - 9722.9 1352 0.18 28.5 705.2±396.1 175.9±35.4 16.6±2.3 y = -32627x2 + 33159x - 7206.2 990 0.27 55.8 436.0±255.4 173.3±52.3 17.1±4.6 y = -19718x2 + 20159x - 4407.7 598 0.46 64.7 347.9±209.6 120.3±18.8 12.8±1.9 y = -14036x2 + 14387x - 3184.1 425 0.54 71.0 286.4±175.8 117.2±37.1 14.4±4.9 y = -13427x2 + 13412x - 2804.1 408 0.50 76.1 235.7±150.7 100.9±1.7 11.3±1.5 y = -9272.7x2 + 9237.5x - 1928.9 280 0.65 83.9 158.4±108.3 63.1±9.5 9.7±2.0 y = -6439.7x2 + 6415.7x - 1344.6 196 0.79 90.0 99.0±65.6 51.2±10.2 11.6±4.1 y = -3893.5x2 + 3886.6x - 814.33 118 1.56 The average PPF in the full sun point should be emphasized since the value found by Cometti & Bugbee was 986.0 µmol m-2 s-1, falling to 99.0 (2010) for curly lettuce at the growing µmol m-2 s-1 with 90% shading (Table productivity optimum calculated in temperature of 25oC during the day and 1). The maximum productivity of fresh 20oC during the night, thereby 0.41 g phytomass was reached at 753 µmol this experiment was around 950 mol mol-1. According to them, below the m-2 s-1 (with 24% actual shading) and aforementioned temperatures, 20/15oC dry mass with 710 µmol m-2 s-1, or 28% photons. This result demonstrates the day/night, the PPE drops to 0.2 g mol-1. shading. Thus, we have a reference Frantz et al. (2004) found higher values, value, between 24 and 28%, for importance of determining PPF when reaching up to 0.8 g mol-1 at temperatures practical purposes of comparison within close to 30oC. However, their studies experiments with shading. The average treatments are related to shading, were carried out with high levels of reading PPF is not always a determining CO2, which speed up the plant growth. factor since variations of temperature allowing this way to make inferences In the present study excessive shading affect the growth of lettuce. Hammer of 90% turns out to be counterproductive et al. (1978), for example, established at any location, or latitude. C3 plants although PPE reached 1.56 g mol-1. the PPF value of 400 µmol m-2 s-1 as the Thus, shading above 50%, despite ideal value for lettuce development in usually saturate with PPF in the range the increase of PPE, does not allow the growth chamber while Galon (2012) sufficient productivity due to absence cultivated the greenhouse lettuce with between 600 and 800 μmol of quanta m-2 of photosynthetic photon volume. The an average PPF of 523 µmol m-2 s-1. PPE stabilizes around 0.5 g mol-1 if the Thus, for comparison purposes, using s-1 (Vieira et al., 2010). In our study, the shading level is up to 70%; this way the variable of incident photosynthetic it does not make the shading above photons (IPP) is preferable since it lettuce grew satisfactorily up to 55.8% 50% to be sufficiently advantageous integrates the total volume of photons for productivity gain. Therefore, we susceptible to assimilation by the plant of actual shading (Figure 3) without suggest the use of this methodology of photosynthetic apparatus. calculation of the PPE since considering compromising productivity, reaching an the methodology is fundamental when Frantz et al. (2004) cultivated interpreting results in order not to lettuce in a growth chamber with high average PPF= 436.0 μmol m-2 s-1 (Table compromise the comparability within performance, and high PPF (800 µmol different experimental situations. m-2 s-1), with a cycle lasting 28 days 1), or IPP= 598 mol m-2 cycle-1 for the until harvest with 16 hours of daily In this experiment, plants were light. By integrating PPF, they had crisp lettuce at average temperature collected at 35 days after transplantation, 1,290.0 mol of incident photosynthetic that is, 60 days after sowing. The photons per square meter. In the present close to 21oC. accumulated degree-days (DD) were experiment (60-day cycle), we obtained 666, with a maximum dry mass by integrating the curves of Table 1, The quantum efficiency (QE) in production of 16.8 g plant-1. Araújo et at full sun, 1,352.0 mol of photons al. (2010) obtained phytomass yields m-2 (Table 1) which is a very close C3 ranges from 15.4 (20oC) to 18.9 ranging from 8 g plant-1 with 514 value to the one obtained by them. degree-days to 19 g plant-1 with 557 However, the presence of photosynthetic mol quanta mol C O -1 (30oC) under degree-days, that means a large range photons incident above the saturation 2 of productivity as a function of several natural CO2 concentration conditions. Considering that the dry mass of the 69 plants contains about 40% of CO2 assimilated in the photosynthesis (Lambers, 2006), in this experiment the quantum efficiency with 55% shading was 240 mol photosynthetic photons mol CO2-1. This considerable difference in relation to the one proposed by Lamber et al. (2006) probably occurs according to the form of calculation used. In this experiment we opted for the actual calculation of photosynthetic photon efficiency (PPE) (Table 1), which comprises the entire cycle even when most of the photons cannot be assimilated because there is not enough leaf area to cover the entire area. Thus, the PPE with 55% shading was 0.46 g mol-1, very close to the maximum Horticultura Brasileira 38 (1) January - March, 2020

NN Cometti et al. factors besides temperature. Madariaga Soares for the technical support, and RW; MCFARLANE, JC. 1978. Base-line & Knott (1951) published a classic one- Evandro de Paula Lima for the text growth studies of ‘Grand Rapids’ lettuce page article pointing to the inefficiency revision. in controlled environments. Journal of the of the thermal accumulation system for American Society of Horticultural Science predicting lettuce harvest. Therefore, the REFERENCES 103: 649-654. accumulation of degree-days cannot be a value analyzed independent of other ARAÚJO, TS; FIDELES FILHO, J; KUMAR, LAMBERS, H; CHAPINIII, FS; PONS, TL. variables. That’s why one should include KK; RAO, TVR. 2010. Crescimento da alface- 2006. Plant physiological ecology. New York: the incident photosynthetic photons as americana em função dos ambientes, épocas Springer, 2006. 540p. an important variable. e graus-dias. Revista Brasileira de Ciências Agrárias 5: 441-449. LEMOS NETO, HS; GUIMARÃES, MA; Concluding, in ambient conditions TELLO, JPJ; MESQUITA, RO; VALE, of photosynthetic photon fluxes around ARDUINO. 2018. Arduino. Available at https:// JC; LIMA NETO, BP. 2017. Productive 1000 μmol m-2 s-1, reaching up to 2000 www.arduino.cc/. Accessed April 4, 2018. and physiological performance of lettuce μmol m-2 s-1 at some times of the day, cultivars at different planting densities in the typical of tropical environment, lettuce BEZERRA NETO, F; ROCHA, RCC; Brazilian Semi-arid region. African Journal culture can support a shading of up NEGREIROS, MZ; ROCHA, RH; of Agricultural Research 12: 771-779. DOI: to 50% without risk of productivity QUEIROGA, RCF. 2005. Produtividade 10.5897/AJAR2016.11961. reduction. de alface em função de condições de sombreamento e temperatura e luminosidade MADARIAGA, FJ; KNOTT, JE. 1951. Lettuce Shading between 20 and 35%, under elevadas. Horticultura Brasileira 23: 189-192. growth rates: investigations find heat unit these conditions, is beneficial and can DOI:10.1590/S0102-05362005000200005.  accumulations not a reliable means of guarantee the maximum productivity to predicting harvest time. California Agriculture the lettuce crop. COMETTI, NN; BUGBEE, B. 2010. 5: 4-4. Produtividade e eficiência fotossintética da We recommended the lettuce alface hidropônica em câmara de crescimento MONDAL, S; GHOSAL, S; BARUA, R. 2016. producer of protected crops to monitor em função do nitrato na solução nutritiva. Impact of elevated soil and air temperature the plastic cover lifespan in order Horticultura Brasileira 28: 877-884. on plants growth, yield and physiological to avoid that the shading exceeds interaction: a critical review. Scientia 50% opacity; the producer is also COSTA, CMF; SEABRA JÚNIOR, S; ARRUDA, Agriculturae 14: 293-305. DOI: 10.15192/ recommended to avoid the use of GR; SOUZA, SBS. 2011. Desempenho de PSCP.SA.2016.14.3.293305 shading screens in greenhouses with cultivares de rúcula sob telas de sombreamento plastic that has already been used e campo aberto. Semina: Ciências Agrárias POLJAKOFF-MAYBER, A; GALE, J. 2012. for some time and may have signs of 32: 93-102. Physiological basis and practical problems dusting and transparency loss. of reducing transpiration. In: KOZLOWSKI, FRANTZ, JM; RITCHIE G; COMETTI, NN; TT (ed). Water deficits and plant growth v. 3. In order to compare shading ROBINSON, J; BUGBEE, B. 2004. Exploring Amsterdam: Elsevier. p.277-306. experiments, we propose to use the the limits of crop productivity: beyond the incident photon flux (mol m-2 cycle-1) limits of tipburn in lettuce. Journal of the SANTOSH, DT; TIWARI, KN; SINGH, VK; for the whole crop cycle, indicating the American Society for Horticultural Science REDDY, ARG. 2017. Micro climate control in minimum limit value of 600 mol m-2 129: 331-338. Available at <http://journal. greenhouse. International Journal of Current cycle-1 for curly lettuce at an average ashspublications.org/content/129/3/331.full. Microbiological Appied Science 6: 1730-1742. temperature close to 21oC. pdf+html>. Accessed July 5, 2017. DOI: 10.20546/ijcmas.2017.603.199 AKNOWLEDGEMENTS GALON, K. 2012. Avaliação do desempenho de SEABRA, S; SOUZA, SBS; THEODORO, VCA; cultivares de alface em cultivo hidropônico NUNES, MCM; AMORIN, RC; SANTOS, We thank IFB for the financial e panorama da hidroponia no Estado do CL; NEVES, LG. 2009. Desempenho de support, Henio Delfino Ferreira de Espírito Santo. UFES, Alegre. 92p. (M.Sc. cultivares de alface tipo crespa sob altas Oliveira for the calculations; José Luiz Dissertation). Available at <http://repositorio. temperaturas. Horticultura Brasileira 27: ufes.br/bitstream/10/6540/1/Karla%20Galon. S3171-S3176. pdf> Accessed August 4, 2018. SILVA, JV; COMETTI, NN. 2017. Estufa GUERRA,AMN; COSTA,ACM; TAVARES, PRF. Inteligente. IFB, Brasília. Available at <https:// 2017. Atividade fotossintética e produtividade play.google.com/store/apps/details?id=com. de alface cultivada sob sombreamento. Revista thunkable.android.josimarviana.Estufa_ Agropecuária Técnica 38: 125-132. DOI: Inteligente&hl=en_US>. Accessed April 4, 10.25066/agrotec.v38i3.29246 2018. HAMMER, PA; TIBBITTS, TW; LANGHANS, TAIZ, L; ZEIGER, E. 2013. Fisiologia Vegetal. 5ª ed. Porto Alegre: Artmed. 918p. VIEIRA, LE; SOUZA, GS; SANTO, AR; SILVA, JS. 2010. Manual de fisiologia vegetal. São Luis: EDUFMA. 230p. 70 Horticultura Brasileira 38 (1) January - March, 2020

Research SILVA, MF; MACIEL, GM; FINZI, RR; PEIXOTO, JVM; REZENDE, WS; CASTOLDI, R. 2020. Selection indexes for agronomic and chemical traits in segregating sweet corn populations. Horticultura Brasileira 38: 71-77. DOI - http://dx.doi.org/10.1590/S0102-053620200111 Selection indexes for agronomic and chemical traits in segregating sweet corn populations Marina F e Silva 1*ID; Gabriel M Maciel 2ID; Rafael R Finzi 1ID; Joicy Vitoria M Peixoto 1ID; Wender S Rezende 3ID; Renata Castoldi 2ID 1Universidade Federal de Uberlândia (UFU), Uberlândia-MG, Brasil; [email protected] (*author for correspondence); [email protected]; [email protected]; 2Universidade Federal de Uberlândia (UFU), Monte Carmelo-MG, Brasil; [email protected]; [email protected]; 3Universidade Federal de Viçosa (UFV), Viçosa-MG, Brasil; [email protected] ABSTRACT RESUMO In the sweet corn breeding, the selection of superior genotypes Índices de seleção para caracteres agronômicos e químicos should consider many traits simultaneously. The best strategy to em população segregante de milho-doce select traits simultaneously is through selection indexes. This study aimed to compare the efficiency of different selection indexes based No melhoramento genético de milho-doce, o processo de seleção on characteristics with direct effect on grain yield in segregating de genótipos superiores deve considerar simultaneamente diversos sweet corn populations. Eighteen traits were evaluated in eight sweet caracteres. A melhor estratégia para a seleção simultânea de caracteres corn genotypes on generation F3. Data were submitted to analyses of é o uso de índice de seleção. Visto isso, o objetivo do trabalho foi variance and path coefficient analyses. We compared the direct and comparar a eficiência desses diferentes índices de seleção com base indirect selection and the following indexes: base, classical, desired nas características que possuem efeito direto na produtividade de gains and genotype-ideotype distance. According to path coefficient grãos em populações segregantes de milho doce. Foram avaliados analyses, the traits which showed a direct effect about grain yield 18 caracteres em oito genótipos de milho-doce na geração F3. Os (GY) were stand, number of ears, ear diameter, number of grains dados foram submetidos à análise de variância e análise de trilha. Foi per row and industrial yield, which composed the indexes. The base comparada a seleção direta e indireta e os seguintes índices: base, index provided the greatest total genetic gain, desired gains on all clássico, seleção de ganhos desejados e distância genótipo-ideótipo. traits, uniform distribution of the gains and considerable gains on GY. De acordo com a análise de trilha, os caracteres que apresentam efeito direto com a produção de grãos (PG) foram estande, número de espigas, diâmetro de espiga, número de grãos por fileira e rendimento industrial, os quais compuseram os índices. O índice base proporcionou o maior ganho de seleção total, ganhos desejáveis positivos em todos caracteres, distribuição uniforme dos ganhos entre as características avaliadas e ganho satisfatório em PG. Keywords: Zea mays subsp. sacharatta, plant breeding, selection Palavras-chave: Zea mays subsp. sacharatta, melhoramento de gain, simultaneous selection of characteristic. planta, ganho de seleção, seleção simultânea de caracteres. Received on October 21, 2019; accepted on February 26, 2020 Sweet corn (Zea mays subsp. The demand for sweet corn has and diameter for processing (Perfeito sacharatta) is a special type of corn increased in Brazil, but the number et al., 2017). Therefore, in the genetic that has a greater concentration of sugars of cultivars adapted to the regions of improvement of sweet corn, the process in the grains in relation to common cultivation is still low, with only 77 of selection of superior genotypes should corn. This characteristic is ruled by registered cultivars (MAPA, 2019). consider several types of characteristics one or more genes of recessive allele, Therefore, it is necessary to intensify simultaneously, such as agronomic, such as genes shrunken and sugary, the development of new materials, chemical and organoleptic properties. which inhibit the conversion of sugars in addition to research related to the into starch in the endosperm, giving improvement of this crop to support In this context, the selection based great palatability (Dodson-Swenson & future breeding programs. A sweet corn only on one trait (direct selection), such Tracy, 2015). In addition, sweet corn is cultivar, besides being productive, must as productivity, is not considered the intended solely for human consumption, have good organoleptic characteristics most appropriated strategy, since there mainly after industrial processing and attend the particularities of the is no guarantee of genetic gains in other (Pereira Filho & Teixeira, 2016). industry, such as appropriated ear length important traits, which may, or may not be correlated to the productivity (Jahufer Horticultura Brasileira 38 (1) January - March, 2020 71

MF Silva et al. & Casler, 2015). To select superior sweet treatments consisted of eight sweet corn significance level. After the detection corn genotypes, various characteristics genotypes from F3 generation (L6P2, of genetic variability for the evaluated (simultaneous selection of traits) can be L6P15, L7P3, L8P7, L8P10, L8P12, traits and the estimation of the evaluated using selection indexes. L8P18, and L9P5), belonging to the components of variance, the diagnosis Vegetable Germplasm Bank of UFU, of multicollinearity of the data was The selection indexes are an analysis Campus Monte Carmelo. This material estimated from the matrix of phenotypic of simultaneously established selection was obtained from three successive self- correlation by the condition number of by a linear combination of traits to fecundations in ears collected in street the matrix (CN) (Montgomery & Peck, maximize the gains from the selection market, initiated in 2016. 1981). The results of the diagnosis were in all the attributes considered (Cruz correlated in direct and indirect effects et al., 2012). There are several reports Seeds were sown in 200- by trial analysis considering the chain of the efficiency of the use of selection cell polystyrene trays for later collinearity (Cruz et al., 2012). For this indexes in relation to the direct selection transplantation, in order to ensure the reason, the constant k was estimated at in crops such as baby corn and green establishment of the targeted population 5.26. Based on the trial analysis, the corn (DoVale et al., 2011), soybean of 50 thousand plants/ha. The trays characteristics were selected for the (Andrade et al., 2016), carrot (Carvalho were filled with substrate and placed composition of the indexes, considering et al., 2017) and passion fruit (Neves et in a greenhouse. Transplanting to the only those with high direct effect on GY. al., 2011). field was performed when the seedlings reached V2 stage. Finally, the base index (Williams, Different methodologies of selection 1962), classic selection index (Smith, indexes have been described such as Seedlings transplantation to the field 1936; Hazel, 1943), desired gains index Smith-Hazel (Smith, 1936; Hazel, was at 4-cm soil depth, spaces between (Pesek & Baker 1969) and genotype- 1943), Pesek-Baker (Pesek & Baker, rows and between plants were 70 and ideotype distance index (Cruz, 2006), 1969) and genotype-ideotype distance 30 cm, respectively. Each plot consisted being the genotype and the ideotype (Cruz, 2006). The comparison between of two rows 5.4 m in length, followed with maximum genotypic values, were the indexes can be performed by means by 0.6 m of alley, with 32 plants observed. For the selection indexes of genetic gains predicted by each per plot and useful area of 7.56 m2. studied, the value of economic weight index or by coincidence in the selection Cropping practices and managements adopted for GY was 2 and for the of superior genotypes (Leite et al., were performed throughout the cycle other characteristics was 1 in which all 2018). There are several studies that in accordance to the recommended for characteristics were evaluated in the have compared the efficiency between the sweet corn culture (Pereira Filho & crescent sense. When the indexes of the selection indexes (Andrade et al., Teixeira, 2016). desired gains were used, the desired gains 2016; Bizari et al., 2017; Missanjo & equivalent to the genotypic standard Matsumura, 2017). However, there are In the R1 stage (female flowering), deviation for each trait was established. still few studies with this approach in the plant stand (STD), number of In addition to the simultaneous selection the sweet corn. prolific plants per plot (PP), number of of traits, analyzes of direct and indirect fasciated plants per plot (FP), number selection considering only one trait were Thus, the objective of this study of leaves per plant (LP), plant stalk performed. In this type of selection, was to compare the efficiency of diameter (SD, cm), plant height (PH, the genotypes were selected based on different selection indexes based on cm) and ear insertion height (EH, cm), the values of a single characteristic characteristics with direct effect on were evaluated. After harvest in R4 and calculated the gains in this same grain yield in segregating sweet corn stage (kernel dough stage), number characteristic (direct selection) as well populations. of ears (NE), ear length (EL, cm), ear as in all other characteristics (indirect diameter (ED, cm), number of rows selection). Unlike the indexes, the direct MATERIAL AND METHODS per ear (NRE), number of grains per and indirect selections were performed row (NGR), grain yield (GY, t ha-1) and based on all evaluated characteristics, The experiment was conducted industrial yield (IY, %), relation between but one at a time. under irrigation by aspersion, in the grain weight and ear weight (%) were period from March 3rd to June 20th evaluated. In addition to the agronomic According to each index, the (2018) at the Experimental Station of characteristics, the grain chemical genotypes were classified, and the Vegetables of the Universidade Federal evaluations regarding the content of three highest scores were selected. de Uberlândia (UFU), Campus Monte soluble solids (SS), carbohydrates Considering the superior genotypes Carmelo, Brazil (18°43’S, 47°31’W, (CAR, %), crude protein (CP, %) selected, the evaluation and comparison 903 m altitude). According to the and lipids (LIP, %) were measured of selection indexes were made by classification of Köppen, the region’s in accordance to the methodology of calculating the selection gain for each climate is tropical. Instituto Adolfo Lutz (2007). characteristic. The selection gain was estimated by the expression G (%) = The experiment was installed in The presuppositions of analysis of (DS x h2) x 100, being G (%)= expected a randomized block design, with 8 variance (ANOVA) were calculated, gain with the selection, DS= selection treatments and three repetitions. The and after acceptance, the data were submitted to ANOVA, with 0.05 72 Horticultura Brasileira 38 (1) January - March, 2020

Selection indexes for agronomic and chemical traits in segregating sweet corn populations differential (the difference between had a direct effect on the GY, once that in a process of simultaneous selection the average of the selected population showed direct effects greater than the of traits, variables with a direct effect among the segregation populations residual effect (0.16). Sesay et al. (2017) on GY can improve the gains on this from F3 generation and the average of also observed direct effects in the ear characteristic. The other characteristics the original segregation population of characteristics, as the number of rows, evaluated did not have a direct effect on the F3 generation, and h2= coefficient diameter, and length on the grain yield grain yield, with values less than 0.16. of heritability in the broad sense. All in hybrid maize populations. Teodoro statistical analyses were performed et al. (2016) concluded that features The trial analysis indicated that the by the computational software Genes not considered as main interest directly characteristics PP, FP, LP, SD, PH, EH, (Cruz, 2013). influence the productivity of grains in EL, NRE, CAR, CP, LIP, and SS had physic nut (Jatropha curcas). Therefore, no direct effect on the GY. Thus, the RESULTS AND DISCUSSION criteria for direct and indirect selection There were significant differences Table 1. Summary of the analysis of variance and estimation of genetic parameters for the among the genotypes for fasciated plants traits of eight sweet corn genotypes. Monte Carmelo, UFU, 2018. (FP), number of leaves per plant (NLP), plant height (PH), ear insertion height Source of Df STD Mean square PH (EH), number of ears (NE), ear length Variation PP FP NLP SD (EL), ear diameter (ED), number of rows per ear (NRE), number of grains per row Genotypes 7 3.02 30.57 56.19** 0.79** 0.11 540.70** (NGR), grain yield (GY) and industrial yield (IY) (Table 1). Identic to the other Blocks 2 4.87 49.62 10.16 1.35 0.09 472.72 characteristics (STD, PP, SD, CAR, CP, LIP, SS), there was no difference Residuals 14 1.40 19.48 5.12 0.12 0.07 28.56 among averages. The identification of genetic variability among the evaluated Average 32.75 12.50 5.16 10.47 2.33 117.32 genotypes allows genetic gains from genotype selection (Cruz et al., 2012). CV (%) 3.61 35.31 43.79 3.28 11.85 4.55 One of the most important parameters CVg (%) 2.24 15.38 79.85 4.53 4.38 11.13 in plant breeding is the heritability, since it is directly related to the genetic CVg/CVe (%) 0.62 0.43 1.82 1.38 0.37 2.44 gain. The heritability coefficients in the experiment ranged from 23.57% h² (%) 53.74 36.27 90.88 85.14 29.15 94.71 (SS) to 94.71% (PH), and GY showed heritability of 66.08%, considered high EH NE EL ED NRE NGR in relation to what was found by Asghar & Mehdi (2010) in sweet corn (38%). Genotypes 7 254.51** 238.08** 1.59* 0.34** 1.58** 31.39* Asghar & Mehdi (2010) also observed NRE with a heritability of 84%, a value Blocks 2 287.89 114.87 1.91 0.16 0.60 15.45 close to that found in the present study (88.71%). Cruz et al. (2012) reported Residuals 14 14.86 40.30 0.55 0.03 0.17 7.36 that the use of secondary traits with high heritability and high correlation Average 57.41 49.12 18.05 4.53 14.64 24.02 with the trait of interest can contribute to increasing the genetic gain. CV (%) 6.71 12.92 4.12 3.98 2.88 11.29 The knowledge about direct and CVg (%) 15.56 16.52 3.26 7.16 4.67 11.78 indirect effects of secondary traits on the main trait, obtained from the trial CVg/CVe (%) 2.31 1.27 0.79 1.79 1.61 1.04 analysis, can optimize the selection indexes since traits of little relevance h² (%) 94.16 83.07 65.28 90.63 88.71 76.54 in the study can be early rejected (Cruz et al., 2012). In accordance to the trial GY IY CAR CP LIP SS analysis in the present study, 97% of the total variation of GY was explained Genotypes 7 7.30* 183.55** 1.29 0.78 0.38 1.43 by the characteristics studied (Table 2). The traits STD, NE, ED, and IY Blocks 2 16.68 52.97 0.07 0.37 0.10 3.13 Residuals 14 2.47 13.50 0.70 0.31 0.23 1.09 Average   7.51 45.18 19.92 6.32 2.63 11.47 CV (%)   20.94 8.13 4.22 8.90 18.17 9.13 CVg (%)   16.87 16.66 2.21 6.20 8.74 2.92 CVg/CVe (%)   0.80 2.04 0.52 0.69 0.48 0.32 h² (%)   66.08 92.64 45.04 59.28 40.99 23.57 **,*= significant at 1 and 5% probability by the F test, respectively; Df= degree of freedom; CV, CVg and CVe= coefficient of variation, coefficient of genetic variation and coefficient of experimental variation, respectively; h²= heritability in the broad sense; STD= plant stand; PP= prolific plants; FP= fasciated plants; NLP= number of leaves per plant; SD= stalk diameter (cm); PH and EH= plant and ear height (cm); NE= number of ears; EL= ear length (cm); ED= ear diameter (cm); NRE= number of rows per ear; NGR= number of grains per row; GY= grain yield (t ha-1); IY= industrial yield (%); CAR, CP and LIP= amount of carbohydrate, crude protein and lipids in grains (%); SS= grain soluble solids (°Brix). Horticultura Brasileira 38 (1) January - March, 2020 73

MF Silva et al. and selection indexes were calculated selection based on a single characteristic with great IY and great NGR, are based on the following characteristics: can occasionally cause unwanted important characteristics for the yield in STD, NE, ED, NGR, GY, and IY. changes in several other traits not the ear industrial processing (Luz et al., considered (Cruz et al., 2012). Carvalho 2014). In addition, the base index was According to Falconer (1987), et al. (2017) reported a reduction in the only one that showed no estimates higher gains offered by indirect selection important traits, such as mass and for undesirable gain. Although this are expected if the heritability of diameter of roots when aiming the index presented an adequate total gain, secondary characteristics is greater improvement of carrot genotypes it does not show the greatest gain in than that of the principal characteristic by selections supported on only the grain yield (GY). Vivas et al. (2013) considered and these characteristics characteristic coloration of roots. emphasized the base index as the most (principal and secondary) are highly suitable for the selection of superior correlated. However, in this work it The base index was the one that genotypes of papaya. does not occur, because all estimated generated the greatest total selection gain direct gains were superior to indirect (sum of gains in all the characteristics The highest estimate of gain in GY gains (Table 3). evaluated), with a value of 38.69% (9.76%) was observed with the classic (Table 4), and also showed a greater indexes. In the same way, in another The direct selection based on gain for IY (13.53%) and NGR (8.71%) study with sweet corn, this was also the GY provided gains (11.65%) for this among all the indexes studied. The one which provided higher gain in GY characteristic and positive gain for improvement of sweet corn genotypes (Asghar & Mehdi, 2010). On the other the other characteristics. However, the Table 2. Direct effects (diagonal in bold) and indirect effects of the variables considered primary on the main variable grain yield (GY), evaluated in eight sweet corn genotypes. Monte Carmelo, UFU, 2018. IE STD PP FP NLP SD PH EH NE EL ED NRE NGR IY CAR CP LIP SS STD 0.28 0.08 0.18 -0.01 0.15 -0.01 -0.03 0.20 0.03 0.01 0.03 0.12 0.03 -0.07 0.02 0.11 0.11 PP 0.01 0.03 0.03 0.02 0.02 0.00 0.01 0.03 0.00 -0.01 0.00 0.02 0.00 -0.01 0.01 0.00 -0.01 FP 0.10 0.13 0.15 0.06 0.10 0.05 0.05 0.14 0.06 -0.05 -0.03 0.08 0.00 -0.08 0.08 0.02 -0.01 NLP 0.00 0.03 0.02 0.06 0.00 0.04 0.02 0.03 0.02 -0.01 0.01 0.00 -0.02 -0.01 0.04 -0.03 0.02 SD -0.04 -0.05 -0.05 0.00 -0.07 0.02 0.01 -0.05 0.02 0.01 0.01 -0.05 -0.01 0.02 0.00 -0.03 0.00 PH 0.00 0.00 -0.01 -0.01 0.00 -0.02 -0.01 0.00 -0.02 0.01 0.01 0.01 0.01 0.01 -0.01 0.00 -0.01 EH 0.01 -0.02 -0.03 -0.03 0.02 -0.07 -0.08 -0.02 -0.07 0.06 0.04 0.03 0.04 0.20 -0.05 0.00 0.01 NE 0.12 0.14 0.16 0.08 0.11 0.04 0.04 0.17 0.05 -0.04 0.01 0.09 0.00 -0.08 0.09 0.00 0.02 EL 0.02 0.02 0.06 0.06 -0.03 0.14 0.14 0.04 0.15 -0.07 -0.08 -0.06 -0.08 -0.10 0.00 0.02 0.02 ED 0.01 -0.10 -0.14 -0.04 -0.07 -0.24 -0.30 -0.11 -0.19 0.41 0.09 0.15 0.27 0.25 0.16 -0.12 0.02 NRE 0.00 0.00 0.01 0.00 0.01 0.01 0.02 0.00 0.02 -0.01 -0.04 0.00 0.00 -0.01 0.00 0.02 -0.01 NGR 0.08 0.13 0.10 0.01 0.13 -0.10 -0.07 0.10 -0.07 0.07 -0.01 0.19 0.13 0.06 0.05 -0.03 -0.06 IY 0.03 0.04 -0.01 -0.12 0.02 -0.22 -0.14 -0.01 -0.15 0.19 0.02 0.20 0.29 0.20 0.14 -0.09 -0.18 CAR -0.01 -0.01 -0.02 -0.01 -0.02 -0.03 -0.02 -0.02 -0.03 0.03 0.01 0.01 0.03 0.05 0.03 -0.03 -0.02 CP 0.01 0.05 0.06 0.08 0.00 0.10 0.08 0.06 0.09 -0.05 0.00 -0.03 -0.06 -0.09 0.12 -0.01 0.02 LIP -0.02 0.01 -0.01 0.03 -0.03 0.00 0.00 0.00 -0.01 0.02 0.03 0.01 0.02 0.04 0.01 -0.06 -0.02 SS 0.02 -0.02 0.00 0.02 0.00 0.02 -0.01 0.01 0.01 0.00 0.02 -0.02 -0.03 -0.02 0.01 0.02 0.05 Total 0.63 0.45 0.52 0.20 0.34 -0.03 -0.28 0.58 -0.07 0.60 0.10 0.77 0.63 0.20 0.04 -0.22 -0.04 Residual effect = 0.16; coefficient of determination = 0.97; constant k= 5.26; IE= indirect effect; STD= plant stand; PP= prolific plants; FP= fasciated plants; NLP= number of leaves per plant; SD= stalk diameter (cm); PH and EH= plant and ear height (cm); NE= number of ears; EL= ear length (cm); ED= ear diameter (cm); NRE= number of rows per ear, NGR= number of grains per row; IY= industrial yield (%); CAR, CP and LIP= amount of carbohydrate, crude protein and lipids in grains (%); SS= grain soluble solids (°Brix). 74 Horticultura Brasileira 38 (1) January - March, 2020

Selection indexes for agronomic and chemical traits in segregating sweet corn populations Table 3. Estimates of selection gains by direct selection (diagonal in bold) and indirect (in rows), for the traits of eight sweet corn genotypes. Monte Carmelo, UFU, 2018. Traits used in the Selected genotypes Selection gains direct and indirect (%) direct selection STD NE ED NGR GY IY STD L6P15, L8P12 and L8P7 1.50 12.00 1.09 3.44 9.90 -2.26 NE L6P15, L8P10 and L8P12 1.32 16.70 -1.62 5.67 9.76 1.77 ED L6P2, L7P3 and L8P7 0.05 -10.73 5.56 1.03 2.54 9.37 NGR L6P15, L6P2 and L7P3 0.19 1.10 2.52 9.60 5.82 10.74 GY L6P15, L7P3 and L8P12 0.77 11.06 1.89 8.86 11.65 4.42 IY L6P15, L7P3 and L8P10 0.41 7.49 0.03 8.71 8.52 13.53 STD= plant stand; NE= number of ears; ED= ear diameter (cm); NGR= number of grains per row; GY= grain yield (t ha-1); IY= industrial yield (%). Table 4. Estimates of selection genetic gain with the use of selection indexes for the traits a balanced distribution of expected of eight sweet corn genotypes. Monte Carmelo, UFU, 2018. gains for all evaluated traits (Bhering et al., 2012; Carvalho et al., 2017; Selection genetic gain (%) Oliveira et al., 2008). Moreover, in the present study, genotype-ideotype Traits Base index Classic index Desired gains Genotype-ideotype distance index presented satisfactory index distance index gain linear diameter; the other indexes provided low gains (base index) or STD 0.41 1.32 0.96 0.96 negative (classic and desired gains) for this characteristic. NE 7.49 16.70 6.74 4.86 The classic index provided higher ED 0.03 -1.62 -0.99 1.43 gain for number of ears, therefore this index selected more prolific NGR 8.71 5.67 6.41 -2.90 genotypes. The prolificacy has not been a characteristic prioritized by breeding GY 8.52 9.76 3.92 6.47 programs of corn (Elias et al., 2010). In addition, on the sweet corn crop, the IY 13.53 1.77 8.08 0.40 priority is the quality of the first ear due to industrial processing (Assunção et al., Total 38.69 33.60 25.12 11.22 2010). For the characteristic NGR, only the genotype-ideotype distance index Selected L6P15, L7P3 L6P15, L8P10 L6P15, L6P2 L8P10, L8P12 and gave negative gain (-2,90%) (Table 4). genotypes L8P7 and L8P10 and L8P12 and L8P10 There were no coincidences in relation to selected genotypes among STD= plant stand; NE= number of ears; ED= ear diameter (cm); NGR= number of grains the studied indexes and also by direct per row; GY= grain yield (t ha-1); IY= industrial yield (%). selection based on GY (Tables 3 and 4). However, the base index and the direct hand, Freitas et al. (2013) found for the achievement of positive gains for the selection based on IY selected the same GY in popcorn no desirable gains by main characteristics in popcorn, while genotypes (L6P15, L7P3 and L8P10). classic indexes. The estimates of gains the indexes of desired gains provided Furthermore, the genotypes L8P18 and by the same indexes do not always show considerable gains only when using L9P5 were the only ones not selected by similar results, because the variables economic weight equal to the genetic any of the indexes. that compose the indexes, the type and standard deviation. number of genotypes available, the Another important factor in the genotype by environment interaction, The selection indexes are efficient, simultaneous selection of characteristics the values of the economic weights and besides presenting favorable genetic is the determination of the economic the accuracy of the matrices of variances gains in all characteristics, especially weights of the main and secondary and covariances interfere in the indexes those of primary interest, although, characteristics; however, in this study, (Cruz et al., 2012). the gains must be well distributed the variations in weights for the same among all traits (Bhering et al., 2012). indexes were not evaluated (Cruz et al., The indexes used in this study, except Although the indexes of desired gains 2012). Generally, the values established the base index, showed no positive and genotype-ideotype distance have for the weights in the indexes may desirable gains for all evaluated traits. presented lower total gains than the influence the expected gains. Bizari Similarly, Oliveira et al. (2008) found base index, they obtained balanced gains that the classic indexes and desired gains between the evaluated characteristics 75 also provided negative gains of some (Figure 1). There are studies that traits in progenies of yellow passion reported the contents of genotype- fruit. However, Santos et al. (2007) ideotype distance as the more suitable used different economic weights and strategy of selection for the simultaneous found that the classic indexes allowed breeding of characteristics, by providing Horticultura Brasileira 38 (1) January - March, 2020

MF Silva et al. Figure 1. Distribution of estimates of genetic gain in line graph by base index, classic index, Crop Breeding and Applied Biotechnology. desired gains and genotype-ideotype distance for the traits of eight sweet corn genotypes. 10: 183-190. Monte Carmelo, UFU, 2018. BHERING, LL; LAVIOLA, BG; SALGADO, CC; et al. (2017) observed that for certain all characteristics, uniform distribution SANCHEZ, CFB; ROSADO, TB; ALVES, indexes, the variation in economic of gains between the characteristics AA. 2012. Genetic gains in physic nut using weights influenced the genetic gains in evaluated and gain satisfactory in grain selection indexes. Pesquisa Agropecuária segregating soybean populations. On yield. The base index allows great Brasileira 47: 402-408. the other hand, estimates of total gain selection gain simultaneously in many were similar among tomato genotypes, important characteristics of sweet corn, BIZARI, EH; VAL, BHP; PEREIRA, EM; DI regardless of the economic weight used which becomes the selection process MAURO, AO; UNÊDA-TREVISOLI, SH. (Nick et al., 2013). There are, however, more efficient. 2017. Selection indices for agronomic traits more recent indexes that do not take into in segregating populations of soybean. Revista account the economic weights, such as ACKNOWLEDGMENTS Ciência Agronômica 48: 110-117. the analysis of factors associated with the main components, PPG-ESIM and This research was supported by CARVALHO, ADF; NOGUEIRA, MTM; FAI-BLUP (DoVale et al., 2011; Cerón- the National Council for Scientific and SILVA, GO; LUZ, JMQ; MACIEL, GM; Rojas et al., 2016; Rocha et al., 2018). Technological Development (CNPq), RABELO PG. 2017. Seleção de genótipos de Coordination for the Improvement of cenoura para caracteres fenotípicos de raiz. The superiority of the selection Higher Education Personnel (CAPES) Horticultura Brasileira 35: 97-102. indexes in relation to other selection and Federal University of Uberlândia methods and from one index to the (UFU). CERÓN-ROJAS, JJ; CROSSA, J; TOLEDO, other is variable (Oliveira et al., 2008). FH; SAHAGÚN-CASTELLANOS, J. This variation depends mainly on REFERENCES 2016. A predetermined proportional gains the accuracy in the estimation of the eigenselection index method. Crop Science variances and covariances genetic ANDRADE, ACB; SILVA, AJ; FERRAUDO, 56: 2436-3447. and phenotypic characteristics, the AS; UNÊDA-TREVISOLI, SH; MAURO, number of genotypes evaluated and AS. 2016. Strategies for selecting soybean CRUZ, CD. 2013. GENES – a software package selected, and, if used, the accuracy in genotypes using mixed models and for analysis in experimental statistics and the determination of economic weights multivariate approach. African Journal of quantitative genetics. Acta Scientiarum 35: or desired gains for each characteristic Agricutural Research 11: 23-31. 271-276. (Asghar & Medhi, 2010; Cruz et al., 2012). ASGHAR, MJ; MEHDI, SS. 2010. Selection CRUZ, CD; REGAZZI, AJ; CARNEIRO, PCS. indices for yield and quality traits in sweet 2012. Modelos biométricos aplicados ao In this study, the base index was corn. Pakitan Journal of Botany 42: 775-789. melhoramento genético – Volume 1. Viçosa: the most efficient in the simultaneous Editora UFV. 514p. selection of characteristics in sweet ASSUNÇÃO, A; BRASIL, EM; OLIVEIRA, JP; corn by providing the largest selection REIS, AJS; PERREIRA, AF; BUENO, LG; CRUZ, CD. 2006. Programa GENES: biometria. gain total, desirable gains positive in RAMOS, MR. 2010. Heterosis performance in Viçosa: Editora UFV. 382 p. industrial and yield components of sweet corn. DODSON-SWENSON, HG; TRACY, WF. 2015. Endosperm carbohydrate composition and kernel characteristics of shrunken2- intermediate (sh2-i/sh2-i Su1/Su1) and shrunken2-intermediate-sugary1-reference (sh2-i/sh2-i su1-r/su1-r) in sweet corn. Crop Science 55: 2647-2656. DOVALE, JC; FRITSCHE-NETO, R; SILVA, PSL. 2011. Índice de seleção para cultivares de milho com dupla aptidão: minimilho e milho verde. Bragantia 70: 781-787. ELIAS, HT; VOGT, GA; VIEIRA, LC; PINHO, RGV; NASPOLINI, V; COVER, C. 2010. Melhoramento genético do milho. In: FILHO, JAW; ELIAS, HT (eds). A cultura do milho em Santa Catarina. Florianópolis: Epagri. p.414-480. FALCONER, DS. 1987. Introdução à genética quantitativa. Viçosa: Editora UFV. 279p. FREITAS, ILJ; AMARAL JUNIOR, AT; VIANA, AP; PENA, GF; CABRAL, OS; VITTORAZZI, C; SILVA, TRC. 2013. Ganho genético avaliado com índices de seleção com REML/Blup em milho-pipoca. Pesquisa Agropecuária Brasileira 48: 1464-1471. HAZEL, HN. 1943. The genetics basis for constructing selection indexes. Genetics 28: 476-490. INSTITUTO ADOLFO LUTZ. 2007. Métodos físico-químicos para análise de alimentos. São Paulo: Valera. 1017p. JAHUFER, MZZ; CASLER, MD. 2015. Application of the Smith-Hazel selection index for improving biomass yield and quality of switch grass. Crop Science 55: 1212-1222. LEITE, WS; UNÊDA-TREVISOLI, SH; SILVA, 76 Horticultura Brasileira 38 (1) January - March, 2020

Selection indexes for agronomic and chemical traits in segregating sweet corn populations FM; SILVA, AJ; DI MAURO, AO. 2018. Fruticultura 33: 1322-1330. analysis and ideotype-design: proposal and Identification of superior genotypes and application on elephant grass breeding for soybean traits by multivariate analysis and NICK, C; LAURINDO, BS; ALMEIDA, VS; bioenergy. Global Change Biology Bioenergy selection index. Revista Ciência Agronômica FREITAS, RD; AGUILERA, JG; SILVA, 10: 52-60. 49: 491-500. ECF; CRUZ, CD; SILVA, DJH. 2013. Seleção simultânea para qualidade do fruto SANTOS, FS; AMARAL JÚNIOR, AT; FREITAS LUZ, JMQ; CAMILO, JS; BARBIERI, VHB; e resistência à requeima em progênies de JÚNIOR, SP; RANGEL, RM; PEREIRA, MG. RANGEL, RM; OLIVEIRA, RC. 2014. tomateiro. Pesquisa Agropecuária Brasileira 2007. Predição de ganhos genéticos por índices Produtividade de genótipos de milho doce 48: 59-65. de seleção na população de milho-pipoca e milho verde em função de intervalos de UNB-2U sob seleção recorrente. Bragantia colheita. Horticultura Brasileira 32: 163-167. OLIVEIRA, EJ; SANTOS, VS; LIMA, DS; 66: 389-396. MACHADO, MD; LUCENA, RS; MOTTA, MAPA - MINISTÉRIO DA AGRICULTURA, TBN; CASTELLEN, MS. 2008. Seleção de SESAY, S; OJO, DK; ARIYO, OJ; MESEKA, PECUÁRIA E ABASTECIMENTO. 2019. progênies de maracujazeiro-amarelo com S; FAYEUN, LS; OMIKUNLE, AO; Registro Nacional de Cultivares. Available base em índices multivariados. Pesquisa OYETUNDE, AO. 2017. Correlation and at http://sistemas.agricultura.gov.br/snpc/ Agropecuária Brasileira 43: 1543-1549. path coefficient analysis of top-cross and three- cultivarweb/cultivares_registradas.php. way cross hybrid maize populations. African Accessed March 26, 2019. PEREIRA FILHO, IA; TEIXEIRA, FF. 2016. Journal of Agricultural Research 12: 780-789. O cultivo do milho-doce. Brasília: Embrapa. MISSANJO, E; MATSUMURA, J. 2017. 298p. SMITH, HF. 1936. A discriminant function for Multiple traits selection index for simultaneous plant selection. Annals of Eugenics 7: 240-250. improvement of wood properties and growth PERFEITO, DGA; LOPES, MCM; SALOMÃO, traits in Pinus kesiya ex Gordon in Malawi. LC; SOUZA, MLC; BENETT, CGS; LIMA, TEODORO, PE; COSTA, RD; ROCHA, RB; Forest 8: 1-7. BP. 2017. Caracterização pós colheita de LAVIOLA BG. Contribution of agronomic milho doce submetido ao parcelamento de traits for grain yield in physic nut. Bragantia MONTGOMERY, DC; PECK, EA. 1981. fertirrigação nitrogenada. Brazilian Journal 75: 51-56. Introduction to linear regression analysis. of Food Technology 20: 2-7. New York: John Wiley. 504p. VIVAS, M; SILVEIRA, SF; VIVAS, JMS; PESEK, J; BAKER, RJ. 1969. Desired PEREIRA, MG. 2013. Predição de ganhos NEVES, LG; BRUCKNER, CH; CRUZ, CD; improvement in relation to selected indices. genéticos e seleção de progênies de mamoeiro VIANA, AP; BARELLI, MAA. 2011. Canadian Journal of Plant Sciences 49: para resistência à pinta-preta. Tropical Plant Predição de ganhos, com diferentes índices 803-804. Pathology 38: 142-178. de seleção, para características de frutos do maracujazeiro-amarelo. Revista Brasileira de ROCHA, JRASC; MACHADO, JC; CARNEIRO, WILLIAMS, JS. 1962. The evolution of a PCS. 2018. Multitrait index bases on fator selection index. Biometrics 18: 375-393. Horticultura Brasileira 38 (1) January - March, 2020 77

Research VALADARES, SV; VALADARES, RV; COSTA, CA; MARTINS, ER; FERNANDES, LA. 2020. Nitrogen sources on yield, mineral nutrition and bromatology of Cyclanthera pedata. Horticultura Brasileira 38: 78-82. DOI - http://dx.doi.org/10.1590/S0102-053620200112 Nitrogen sources on yield, mineral nutrition and bromatology of Cyclanthera pedata Samuel V Valadares 1ID; Rafael V Valadares 2ID; CandidoACosta 3ID; Ernane R Martins 3ID; LuizAFernandes 3ID 1Universidade Federal de Viçosa (UFV), Viçosa-MG, Brasil; [email protected]; 2Universidade Estadual de Campinas (NIPE, UNICAMP), Campinas-SP, Brasil; [email protected]; 3Universidade Federal de Minas Gerais (UFMG), Montes Claros-MG, Brasil; [email protected]; [email protected]; [email protected] ABSTRACT RESUMO Caygua fruits (Cyclanthera pedata) are used both in cooking Fontes de nitrogênio na produtividade, nutrição mineral e and for medicinal purposes. However, few studies on this species, bromatologia do maxixe do reino considered a non-conventional vegetable, can be found in literature. This study aimed to assess the responses of caygua crop Os frutos do maxixe do reino (Cyclanthera pedata) são utilizados to green manure and mineral nitrogen fertilization, in relation to tanto na culinária quanto para fins medicinais. No entanto, há marketable fruit productivity, nutrient content in leaves and fruits poucos estudos sobre essa espécie, considerada cucurbitácea não and bromatological composition. The study was carried out in a convencional. Esta pesquisa teve por objetivo estudar as respostas randomized block design with four treatments and five replicates: da cultura do maxixe do reino à adubação verde e mineral com 1) control (without nitrogen); 2) 60 kg ha-1 nitrogen (urea form); 3) nitrogênio na forma de ureia, quanto à produtividade de frutos green manuring using Cajanus cajans and 4) green manuring using comerciais, teor de nutrientes nas folhas e frutos e composição Crotalaria juncea. The plots consisted of three caygua lines with four bromatológica. O experimento foi conduzido em delineamento de plants per line (spacing 2x1 m). In the treatments using green manure, blocos casualizados com quatro tratamentos e cinco repetições: 1) three lines of these respective legumes were cultivated. We evaluated controle (sem nitrogênio); 2) 60 kg ha-1 de nitrogênio na forma de marketable fruit productivity, nutrient contents in fruits and leaves and ureia; 3) adubação verde com Cajanus cajans e 4) adubação verde bromatological composition of the fruits. Production of caygua fruits com Crotalaria juncea. As parcelas foram constituídas por três linhas was higher in the treatment consisting of urea application (23.6 t ha-1), de maxixe do reino com quatro plantas por linha, no espaçamento followed by Crotalaria juncea (15.6 t ha-1), Cajanus cajans (14.8 t de 2x1 m. Nos tratamentos com adubo verde foram cultivadas três ha-1) and control (9.2 t ha-1). Treatments did not influence the nutrient linhas das respectivas leguminosas. As variáveis avaliadas foram contents in fruits and leaves and the bromatological composition. produtividade de frutos comerciais, teores de nutrientes nos frutos However, in relation to higher productivity, the amounts of nutrients e nas folhas e composição bromatológica dos frutos. A produção de absorbed by plants and accumulated in fruits were higher in treatments frutos do maxixe do reino foi maior no tratamento com aplicação using mineral fertilization due to the higher yield. The bromatological de ureia (23,6 t ha-1), seguida pela Crotalaria juncea (15,6 t ha-1), analysis of fruits showed considerable contents of crude protein and Cajanus cajans (14,8 t ha-1) e testemunha (9,2 t ha-1). Os tratamentos ether extract, highlighting the potential of this species to human diet. não influenciaram nos teores de nutrientes nos frutos e folhas e a composição bromatológicas dos frutos. No entanto, em função da maior produtividade, as quantidades de nutrientes absorvidas pelas plantas e acumuladas nos frutos foram maiores nos tratamentos com adubação mineral. A análise bromatológica dos frutos revelou consideráveis teores de proteína bruta e extrato etéreo, ressaltando o potencial desta espécie para a dieta alimentar humana. Keywords: Cyclanthera pedata, green manuring, non-conventional Palavras chave: Cyclanthera pedata, adubação verde, olerícola não vegetable, medicinal plant. convencional, planta medicinal. Received on August 12, 2019; accepted on February 20, 2020 Caygua (Cyclanthera pedata) is are dedicated exclusively to human Peru (Fernandes et al., 2005). a non-conventional vegetable consumption, in food or in the medicine Deep soils with pH close to neutrality belonging to Cucurbitaceae family, production (Costa et al., 2008; Macchia with indeterminate growth habit, oblong et al., 2009). This species is found are considered suitable for the crop fruits, simple and palminerous leaves growing under spontaneous or sub- growth. The cycle is approximately and unisexual flowers at the leaf axilla spontaneous conditions, mainly in 100 days counting from the crop (Macchia et al., 2009). Caygua fruits Bolivia, Chile, Colômbia, Argentina and establishment to first harvest, continuing for another 45 to 60 days (Macchia et 78 Horticultura Brasileira 38 (1) January - March, 2020

Nitrogen sources on yield, mineral nutrition and bromatology of Cyclanthera pedata al., 2009). characteristics: pH, water = 4.5; P= 1.0 monthly applications of 20 kg ha-1 N in mg dm-3; Ca= 2.1 mmolc dm-3; Mg= 0.8 urea form, beginning at planting. Green In Brazil, in the Northern mmolc dm-3; K= 0.5 mmolc dm-3; Al= manure was sown continuously, at the Region of Minas Gerais State, 23 mmolc dm-3; H+Al= 110 mmolc dm-3; same planting date of caygua plants, caygua plants are especially grown Zn= 0.3 mg dm-3; Mn= 2.2 mg dm-3; in furrows, spacing 50 cm from each by family farmers, where the fruits are Fe= 8.3 mg dm-3; Cu= 0.1 mg dm-3; other, thinning at 10 days after seedling traded in local markets (Fernandes et B= 0.1 mg dm-3; organic matter = 18 g emergence, keeping planting density of al., 2005; Costa et al., 2008). According kg-1; sand = 500 g kg-1; silt = 80 g kg-1 30 plants per linear meter. Both green to these authors, production areas are and clay = 420 g kg-1. The soil analysis manures were cut and incorporated restricted to more fertile soils and was performed following the methods into soil when 50% of the plants started their productivities are related, among described by Embrapa (1997). flowering, considering that the crotalaria other factors, to the crop nutritional was incorporated at 60 days and pigeon management. Due to these peculiarities The experimental design was pea at 120 days after sowing. of producers and consumers, no records randomized blocks, with four treatments in statistical yearbooks on the Brazilian and five replicates. The treatments During the trial period, two production of caygua fruits can be found consisted of: 1) control (without manual weedings were performed and (Fernandes et al., 2013). nitrogen); 2) 60 kg ha-1 nitrogen (urea complementary irrigation was carried form); 3) intercropped with pigeon-pea out through drip system. Nitrogen is the most required (Cajanus cajans) cv. IAPAR 43 Aratã) nutrient by caygua plants, and is one and 4) intercropped with crotalaria In order to analyze leaf nutrient of the most limiting growth factors for (Crotalaria juncea). contents, two mature leaves were this crop. So, developing alternative collected from the middle third of nutritional management techniques The plots consisted of three lines each plant, one leaf on each side of the related to nitrogen supply is necessary of caygua with four plants per line, vertical trellis system and fruits were to produce this vegetable on small-scale conducted in vertical trellis system, harvested manually when they reached farms (Fernandes et al., 2005). spacing 2 m between lines and 1 m commercial standard, approximately 12 between plants. In the treatments using cm long (2 harvests). The use of green manures, with green manure, three lines of these nitrogen fixing species, is widely legumes were grown in spacing 0.5 m Fruits and leaves were oven dried recommended for providing nitrogen- between lines. In the plots using urea, until constant weight at 60°C, and they rich plant residues to replace or weeding was done manually between were chemically analyzed considering complement mineral fertilization lines. The useful plot consisted of two N, P, K, Ca, Mg, S, B, Zn, Fe and Mn (Duarte et al., 2013; Zhang et al., 2017; central plants in the central line. using the methodology proposed by Sarmento et al., 2019). Moreover, this Malavolta et al. (1997). practice contributes to the reduction Three months before implementing of greenhouse-gas emissions by the experiment, the soil was plowed Samples consisting of 10 fruits agricultural activities (Forte et al., 2017; and harrowed. Furrows were opened per plot were randomly collected and Fungo et al., 2019). in 30-cm-deep lines and liming was analyzed considering the following performed using dolomitic limestone, bromatological characteristics: This study aimed to assess the in order to reach 60% of base saturation moisture, total dry matter, macro and responses of caygua plants to green (Fernandes et al., 2005). The basic micronutrients, crude protein, ether manure and mineral fertilizations, in fertilization consisted of applying 20 L extract, ash and crude fiber. relation to marketable fruit productivity, m-¹ cattle manure into sowing furrows. nutrient content in leaves and fruits and Furthermore, 30 days before planting, All variables were submitted to bromatological composition. 30 g m-1 of P2O5 in the form of reactive variance analysis and treatment averages phosphate rock, at planting, and 40 g were compared using Tukey test at 5% MATERIAL AND METHODS m-1 of K2O were was applied in the form probability. SAEG statistical software, of potassium chloride, splitted in two System for Statistical and Genetics The experiment was carried out in applications, half at planting and half Analyses was used (Ribeiro Júnior, the field, from February to October, after 40 days. Analytical determinations 2001). 2010, at Instituto de Ciências Agrárias of of the cattle manure according to the Universidade Federal de Minas Gerais, methodology presented by Fermino et RESULTS AND DISCUSSION Montes Claros campus (16°40’51”S, al. (2000) presented: C/N= 16.6; total 43°50’22”W, 650 m altitude). The N= 21 g kg-1; P2O5= 9.8 g kg-1; K2O= Productivity of marketable caygua regional climate, according to Köppen, 10.6 g kg-1; CaO= 12.8 g kg-1; MgO= 6.5 fruits was affected by the treatments is Aw, tropical savanna, dry winter, g kg-1; S= 0.1 g kg-1; B= 38 mg kg-1; Zn= (Figure 1), plant yield increased with rainfall concentration in summer 84 mg kg-1; Fe= 15.3 g kg-1; Mn= 250 156.52% with mineral fertilization (Alvares et al., 2013). mg kg-1; Cu= 36 mg kg-1 dry mass base. when compared to the control treatment. Green manures intercropping treatments The soil in the experimental area The treatment using mineral presented average productivities of is an Oxisol, showing the following fertilization was applied in three marketable fruits 69.57 and 60.87% Horticultura Brasileira 38 (1) January - March, 2020 79

SV Valadares et al. greater than the control, respectively for climate and plant species (Sharifi et al., significant effects on the contents may the treatments pigeon pea and crotolaria. 2009; Diniz et al., 2014). be associated with the effects of nutrient These results are corroborated by dilution, since nitrogen is a nutrient Fernandes et al. (2005), who reported a In addition to making nitrogen that highly affects plant growth (Weih high caygua crop N demand, considering available, green manures contribute et al., 2011). In the treatment using N the most extracted nutrient by plants positively to the root system of crops in urea, although the nutrient content in of this species. intercropping or succession (Valadares the plant is similar to that of the other et al., 2012, 2016). Miyazawa et al. treatments, fruit production was 2.58, In the present study, the maximum (2010), studying the root systems of 1.51 and 1.78 times greater than the production of commercial caygua legume species intercropped with control treatments, green manure using fruits was 23.6 t ha-1, obtained applying grasses, observed that both Crotalaria pigeon pea and green manure with urea (Figure 1). This productivity juncea and sorghum showed greater crotalaria, respectively (Figure 1). Thus, corresponded to 72.8% of the maximum distribution of roots when compared to effects of applying N are associated with production obtained by other authors monoculture, showing complementarity increases in macro and micronutrients (Fernandes et al., 2013), under similar in the exploitation of soil resources. accumulation in caygua fruits (Table 2). conditions. No significant differences for We found no difference among The high capacity of nitrogen supply nutrient contents among treatments, treatments for the bromatological by green manures is associated with both in fruits and leaves were verified properties of caygua fruits (Table 3). the capacity for biological N2 fixation in our study (Table 1). The absence of resulting from the symbiosis between legumes and bacteria (Brito et al., Figure 1. Marketable caygua fruit productivity in relation to nitrogen source (variation 2011), as well as their indirect benefits coefficient 8.6%). Averages followed by same letters did not significantly differ, Tukey’s for improving soil chemical, physical test, 5%. Montes Claros, ICA-UFMG, 2020. and biological properties (Duarte et al., 2013). On the other hand, it is also worth Table 1. Nutrient contents in caygua fruits and leaves. Montes Claros, ICA-UFMG, 2020. mentioning that the green manures grown intercropped may compete for Nutrient Content in Variation Content in Variation growth resources with the main crop (Miyazawa et al., 2010; Valadares et fruits (g kg-1) coefficient (%) leaves (g kg-1) coefficient (%) al., 2012, 2016). This fact can help to explain the lowest productivity in N 21.8 8.5 31.8 5.6 the treatments which contained green manure compared with the treatment P 6.0 9.2 2.8 4.8 using mineral fertilizer (Figure 1). K 38.4 7.3 25.3 6.8 In addition, the supply of N mineralized from the green manures Ca 4.2 5.8 31.4 6.4 biomass mismatched the periods of highest nutritional demand of the caygua Mg 2.1 9.4 5.1 8.2 plants. (Sharifi et al., 2009) considering that incorporation of crotalaria and S 2.0 13.4 2.3 12.4 pigeon pea was at 60 and 120 days, respectively, after planting. (mg kg-1) (%) (mg kg-1) (%) Our results show that further studies B 10.3 8.9 26.9 9.5 on sowing of green manure in pre planting for this crop are necessary. Zn 21.3 5.4 24.8 7.2 Guedes et al. (2010) recommend legume planting for obtaining green manure Fe 12.3 6.8 358.6 12.6 with the necessary advance so that nitrogen mineralization coincides with Mn 5.9 8.1 33.2 11.8 the nutritional requirements of the main crop. Horticultura Brasileira 38 (1) January - March, 2020 Future studies should also consider variations in green manure planting density in order to better meet the nutritional requirements of caygua fruits, as well as, other factors that affect N mineralization and the response of crops to these practices, such as soil, 80

Nitrogen sources on yield, mineral nutrition and bromatology of Cyclanthera pedata These results show that even under Fruit production was dependent Cooperation of the Coordination for lower nitrogen availability, such as in the on nitrogen, considering that higher the Improvement of Higher Education control treatment, the fruits maintained productivities were obtained in the Personnel (CAPES/Brazil), by the their bromatological properties at the treatment with urea application, Brazilian National Council for Scientific expense of production. On the other followed by pigeon pea and crotalaria and Technological Development hand, considering dry mass production green manures. (CNPq/Brazil) and by the Foundation (Figure 1), the amount of protein for Research Support of São Paulo produced per hectare corresponded The treatments did not influence the (FAPESP) (n° 2018/24707-0). The to: control (68.61 kg ha-1), pigeon pea plant nutrient content in the plant and authors are grateful for the scholarships (117.37 kg ha-1), crotolaria (99.9 kg ha-1) the fruit bromatological composition. granted. and urea (163.05 kg ha-1). However, the highest amounts of nutrients accumulated in the fruits REFERENCES Crude protein contents in caygua occurred in treatments with mineral fruits were similar to the ones found fertilization. ALVARES, CA; STAPE, JL; SENTELHAS, PC; in cucumber fruits (Cucumis anguria) GONÇALVES, JLM; SPAROVEK, G. 2013. (Lima et al., 2006), which also belongs ACKNOWLEDGEMENTS Köppen’s climate classification map for Brazil. to Cucurbitacea family. In addition to Meteorologische Zeitschrift 22: 711-728. the potential benefits to human nutrition, This research was supported by caygua also presents therapeutic the Minas Gerais State Foundation for BRITO, MMP; MURAOKA, T; SILVA, EC. properties with anti-inflammatory, Research Support (FAPEMIG/Brazil), 2011. Contribuição da fixação biológica hypoglycemic and hypocholesterolemic by the National Program for Academic de nitrogênio, fertilizante nitrogenado e action (Carbone et al., 2004). nitrogênio do solo no desenvolvimento de feijão e caupi. Bragantia 70: 206-215. Table 2. Nutrient accumulation in caygua fruits in relation to nitrogen sources. Montes Claros, ICA-UFMG, 2020. CARBONE, V; MONTORO, P; TOMMASI, N; PIZZA, C. 2004. Analyzis of flavonoids Nutrient Control Urea Pigeon pea Crotalaria Variation from Cyclanthera pedata chromatography/ electrospray mass spectrometry. Journal of (kg ha-1) coefficient (%) Pharmaceutical and Biomedical Analyzis 34: 295-304. N 12.02c 28.28a 19.03b 16.46b 7.6 COSTA, CA, RAMOS, SJ, ALVES, DS, P 3.40c 7.10a 5.51b 4.72b 8.6 FERNANDES, LA, SAMPAIO, RA, MARTINS, ER. 2008. Nutrição mineral do K 21.49c 45.59a 33.70b 31.33b 7.6 mangarito num Latossolo Vermelho Amarelo. Horticultura Brasileira 26: 102-106. Ca 2.31c 4.99a 3.82b 3.36b 7.2 DINIS, ER; VARGAS, TO; REREIRA, WD; Mg 1.15c 2.44a 1.96b 1.60b 9.4 GUEDES,AF; SANTOS RHS; PETERNELLI, LA. 2014. Decomposição e mineralização S 1.09c 2.55a 1.87b 1.52b 12.4 do nitrogênio proveniente do adubo verde Crotalaria juncea. Científica 42: 51-59. (g ha-1) (%) DUARTE, RF; FERNANDES, LA; SAMPAIO, B 5.95c 11.42a 8.63b 9.11b 6.5 RA; SANTOS, LDT; GRAZZIOTTI, PH; SILVA, HP. 2013. Biomass yields, soil cover, Zn 11.96c 23.63a 20.63b 16.62b 7.9 content and accumulation of nutrients of some green manure legumes grown under Fe 6.86c 14.09a 10.58b 10.47b 10.4 conditions of north of Minas Gerais, Brazil. African Journal of Agricultural Research 8: Mn 3.34c 6.88a 5.25b 4.88b 11.3 2430-2438. 1Averages followed by same letters did not significantly differ, Tukey’s test, 5%. EMBRAPA. Centro Nacional de Pesquisa de Solos. 1997. Manual de métodos de análise Table 3. Bromatological parameters of caygua fruits. Montes Claros, ICA-UFMG, 2020. de solos. 2.ed. Rio de Janeiro. 212p. Properties Average values Variation coefficient FERMINO, MH; TRENTIN, AL; KÄMPF, AN. (%) (%) 2000. Caracterização física e química de Total moisture of fresh sample 94.4 14.5 materiais alternativos para composição de Dry matter of fresh sample 5.6 10.2 substratos para plantas: 1. Resíduos industriais Crude protein 12.9 13.7 e agrícolas. In: KÄMPF, NA; FERMINO, Total moisture of dry sample 9.1 12.6 MH. (eds). Substratos para plantas: à base da Total dry matter of dry sample 90.9 15.8 produção vegetal em recipientes. Porto Alegre: Ethereal extract (% of dry matter) 3.9 16.9 Genesis. p.241-248. Ashes (% of dry matter) 10.7 12.4 Crude fiber (% of dry matter) 20.3 16.4 F E R N A N D E S, L A; VA L A D A R E S, RV; VALADARES, SV; RAMOS, SJ; COSTA, CA; SAMPAIO, RA; MARTINS, ER. 2013. Fontes de potássio na produtividade, nutrição mineral e bromatologia do maxixe do reino. Horticultura Brasileira 31: 607-612. FERNANDES, LA; ALVES, DS; RAMOS, SJ; OLIVEIRA, FA; COSTA, CA; MARTINS, ER. 2005. Nutrição mineral de plantas de Horticultura Brasileira 38 (1) January - March, 2020 81

SV Valadares et al. maxixe do reino. Pesquisa Agropecuária Cyclanthera pedata Schrad. cultivated in Manual de métodos de análise de solo. 3. ed. Brasileira 40: 719-722. central Italy. African Journal of Microbiology Brasília: Embrapa Informação Tecnológica. Research 3: 434-438. 573p. FORTE, A; FAGNANO, M; FIERRO, A. 2017. Potential role of compost and green manure MALAVOLTA, E; VITTI, CG; OLIVEIRA, VALADARES, RV; DUARTE, RF; MENEZES, amendment to mitigate soil GHGs emissions SA. 1997. Avaliação do estado nutricional JBC; FERNANDES, LA; SANTOS, LDT; in Mediterranean drip irrigated maize das plantas: princípios e aplicações. 2ª SAMPAIO, RA; MOTA, TC; ALMEIDA, RM. production systems. Journal of Environmental ed. Piracicaba: Associação Brasileira para 2012. Fertilidade do solo e produtividade de Management 192: 68-78. Pesquisa da Potassa e do Fosfato, 319p. milho em sistemas de adubação verde no norte de Minas Gerais. Planta Daninha 30: 505-516. FUNGO, B; LEHMANN, J; KALBITZ, K; MIYAZAWA, K; MURAKAMI, T; TAKEDA, M; THIONĢO, M; TENYWA, M; OKEYO, I; MURAYAMA, T. 2010. Intercropping green VA L A D A R E S , RV; Á V I L A - S I LVA , L ; NEUFELDT, H. 2019. Ammonia and nitrous manure crops effects on rooting patterns. Plant TEIXEIRA, RS; SOUSA, RN; VERGÜTZ, oxide emissions from a field Ultisol amended and Soil 331: 231-239. L. 2016. Green manures and crop residues as with tithonia green manure, urea, and biochar. source of nutrients in tropical environment. In: Biology and Fertility of Soils 55: 135-148. RIBEIRO JÚNIOR, JI. 2001. Análises estatísticas LARRAMENDY, M; SOLONESKI, S (eds). no SAEG. Viçosa: UFV, 2001. 301p. Organic fertilizers – from basic concepts to GUEDES, RE; RUMJANEK, NG; XAVIER, applied outcomes. London: INTECH p.51-84. GR; GUERRA, JGM; RIBEIRO, RLD. SARMENTO, JJA; SANTOS, JJF; COSTA, 2010. Consórcios de caupi e milho em cultivo CC; BOMFIM, MP. 2019. Agronomic WEIH, M; ASPLUND, L; BERGKVIST, G. orgânico para produção de grãos e espigas performance of lettuce subjected to green 2011. Assessment of nutrient use in annual verdes. Horticultura Brasileira 28: 174-177. manure with different leguminous species. and perennial crops: A functional concept for Revista Brasileira de Engenharia Agrícola e analyzing nitrogen use efficiency. Plant and LIMA, AS; TRANCOSO, FO; MOURA, KM; Ambiental 23: 14-118. Soil 339: 513-520. ALMEIDA, LB; SILVA, TNS; SOUZA, WM; MARCELLINI, OS. 2006. Caracterização SHARIFI, MZ; MATSUMURA, S; HIRASAWA, ZHANG, X; ZHANG, R; GAO, J; WANG, centesimal de maxixe e sua aplicação na T; KOMA, TM. 2009. Apparent nitrogen X; FAN, F; MA, X; YIN, H; ZHANG, C; produção de picles. Alimentos Nutrição 17: mineralization rates of several green manures FENG, K; DENG, Y. 2017. Thirty-one years 407-412. incorporated in soil and the application effects of rice-rice-green manure rotations shape on growth of Komatsuna plants. Japanese the rhizosphere microbial community and MACCHIA, M; MONTORO, P; CECCARINI, L; Journal of Farm Work Research 44: 163-172. enrich beneficial bacteria. Soil Biology and MOLFETTA, I; PIZZA, C. 2009. Agronomic Biochemistry 104: 208-217. and phytochemical characterization of TEIXEIRA, PC; DONAGEMMA, GK; FONTANA, A; TEIXEIRA, WG. 2017. 82 Horticultura Brasileira 38 (1) January - March, 2020

Research TEIXEIRA, AG; OLIVEIRA, FL; PARAJARA, MC; ZUCOLOTO, M; DALVI, LP. 2020. Yacon planting density in intercropping with corn under banana orchard. Horticultura Brasileira 38: 83-88. DOI - http://dx.doi.org/10.1590/S0102-053620200113 Yacon planting density in intercropping with corn under banana orchard Ariany das Graças Teixeira 1ID; Fábio Luiz de Oliveira 1ID; Magno do C Parajara 1ID; Moises Zucoloto 1ID; Leandro P Dalvi 1ID 1Universidade Federal do Espírito Santo (UFES), Alegre-ES, Brasil; [email protected]; [email protected]; fabiocapi@ yahoo.com.br; [email protected]; [email protected]; [email protected] ABSTRACT RESUMO Yacon is a crop which requires development of strategies for its Densidade de plantio de yacon em consórcio com milho sob cultivation. One of the possibilities is to introduce yacon in perennial pomar de bananeira crops using intercropping system. The aim of this study was to evaluate different planting densities of yacon grown in intercropping with corn Yacon é uma cultura que demanda desenvolvimento de estratégias under banana orchard, verifying its development and production. At para seu cultivo. Dentre as possibilidades, está a introdução da 90 days after planting, morphological and physiological evaluations yacon em lavouras perenes através de consórcios. Objetivou-se were done, at 210 days yacon was harvested, and its productivity com o presente trabalho avaliar diferentes densidades de plantio de calculated using the fresh tuberous root production. The Area yacon cultivada em consórcio com milho, sob pomar de bananeira, Equivalence Index (IEA), and the Relative Contribution of Crops verificando seu desenvolvimento e produção. Aos 90 dias após o (CRC) to IEA were calculated. Yacon development and production plantio foram realizadas avaliações morfológicas e fisiológicas, aos were hampered by the corn intercropping (under the banana orchard), 210 dias a colheita da yacon, e sua produtividade calculada a partir regardless of the yacon density used. IEA increased with yacon da produção de raízes tuberosas frescas. Calculou-se o Índice de and corn intercropping in relation to greater CRC of corn to the Equivalência de Área (IEA), e a Contribuição Relativa das Culturas intercropping and its market value, the system presented higher (CRC) ao IEA. O desenvolvimento e produção da yacon foram gross income. Planting yacon under banana orchard optimizes the prejudicados pelo consórcio com o milho (sob o pomar da bananeira), use of the area and it is profitable for the farmer, especially when independente da densidade de yacon utilizada. O consórcio yacon- yacon is planted in double rows, alternating between banana rows, milho aumentou o IEA e, em função da maior CRC do milho ao spacing 0.3 and 0.4 m. consórcio e seu valor de mercado, o sistema apresentou maior renda bruta. O plantio de yacon sob pomar de bananeira otimiza o uso da área sendo rentável ao agricultor, sobretudo quando a yacon é plantada em linhas duplas, alternando nas entrelinhas da bananeira, nos espaçamentos 0,3 e 0,4 m. Keywords: Smallanthus sonchifolius, spacing, polyculture, shading. Palavras-chave: Smallanthus sonchifolius, espaçamento, policultivo, sombreamento. Received on May 6, 2019; accepted on February 2, 2020 Since 80’s, yacon has become popular Santo (Oliveira et al., 2013). expanding the food supply and in different countries in South generating income for farmers. America (Brazil and Paraguay), and also Yacon is a functional food and it has in countries in other continents, such stood out in food technology industry, In theAndes, where yacon originated, as New Zealand (Oceania), Japan and as it shows prebiotic activities and for it is also cultivated in edges of corn and Korea (Asia), Czech Republic (Europe) its sweet taste of fructans such as inulin vegetable crops, or associated with corn, and the United States (Seminario et al., and fructooligosaccharides (FOS), beans, potatoes, cabbage, parsnips, 2003). promoting positive health outcomes coffee and fruits (Seminário et al., 2003), (Sacramento et al., 2017). Nevertheless, considering its potential to be explored In Brazil, yacon started to be as it is still an emerging crop, yacon as an income-generating alternative for cultivated in 90’s, in São Paulo State, planting areas can be expanded through family farming (Villamiza et al., 2014). especially in the municipality of Capão developing strategies for its cultivation. Bonito. However, as the vegetable started Among the possibilities, yacon can According to Teixeira (2018), yacon to be more and more consumed, from be intercropped with perennial crops plants which have been growing under the year 2000, yacon was introduced already known, which is an interesting moderate shade levels (30 to 50%) in other states, such as Minas Gerais, suggestion, since it could mean a showed greater capacity for total biomass Parana, Rio de Janeiro and Espírito diversification of production system, accumulation, part of this accumulation for the tuberous roots, which directly Horticultura Brasileira 38 (1) January - March, 2020 83

AG Teixeira et al. reflects in agronomic productivity gains. on lines between species, which would = 60%; silt = 5%; clay = 35%. According to Tomazini et al. (2009), further contribute to optimize the use yacon shows to be quite tolerant to of the area and to increase the farmer’s The experimental design was variations in light quantity, growing income. completely randomized, with six under tree and bush shadows, attributing replicates, arranged in split plot scheme to these plants important characteristics In this context, it is possible to in space, considering the plot the three to compose intercropped production insert another crop which is compatible yacon planting densities (11,111; 8,333 systems, including agroforestry. Thus, with yacon and banana, showing fast and 6,666 plants ha-1), and split plot it is possible to grow yacon with other growth and short cycle, choosing corn, factor the presence and absence of corn larger species, such as fruitful species, to be harvested in green stage, since its intercropping. constituting intercropped systems. demand for its relevance in Brazilian cuisine and, because of its commercial The densities used in the plots were Among the crops which can be value, which optimizes the use of the calculated using the equation: 5m +1m diversified with the introduction of area and would increase the farmer’s (plot area) x spacing between plants; yacon, banana crop stands out since income (Pereira Filho et al., 2015). with plant population of 11,111 plants it is of great importance for Brazil per hectare, spaced 0.3 m between (planted area of approximately 477.3 Thus, the aim of this study was to plants; 8,333 plants per hectare spaced thousand hectares) (Seapa, 2017). It is evaluate different planting densities of 0.4 m, and 6,666 plants per hectare one of the main crops in Espírito Santo yacon grown intercropped with corn, spaced 0.5 m. State, with a total planted area of 26,320 under banana orchard, verifying its hectares and average production around development and production. We used this way to calculate 277 thousand tons (Incaper, 2017), densities since yacon was planted in two predominantly banana (Prata variety), MATERIAL AND METHODS rows (spaced 1.0 m between rows, and mostly produced by family-based spacing between plants following the farmers, which makes it an activity of The experiment was carried out from treatment mentioned above), alternating great social importance. October 2016 to December 2017, in the rows of banana plants. The spacing the experimental area of Universidade used in banana plants was 3x2 m. Moreover, banana plant is considered Federal do Espírito Santo (UFES) in We used cultivar BRS Vitória, group an ideal component for intercropping Rive, district of Alegre, Espírito Santo Prata, for banana orchard, at the stage in general, since this plant provides State, Brazil (20°45’49’’S, 41°29’59”W, which corresponds to the end of the several benefits to the systems, such altitude 113 m). The area is located in juvenile phase and the beginning of as minimize the incident global solar Rio Itapemirim Valley, a warm tropical the reproductive phase at 180 days; the radiation, adjust the photosynthetic rates micro region (lowlands), with higher shoot emission was at 90 and 120 days, in case of an excess of light, minimize temperatures (Pezzopane et al., 2012). conducted with management practices high temperatures, and increase the During the experiment, maximum (fertilization, sprout thinning) based productive capacity of shaded species temperatures ranged from 28 to 36°C on the manual of recommendation for (Araújo et al., 2015), making large and minimum from 15 to 20°C, with bananas (Embrapa, 2012). amounts of biomass available to the accumulated rainfall 1538.2 mm (data system obtained from automatic weather station In split plots, the one with corn of Instituto Nacional de Meteorologia of intercropping, three rows were sown in The success of the intercropping Brazil-INMET, Alegre-ES), located near order to involve the two rows of yacon between plants will depend on some the experiment. (equidistant 0.5 m from the rows), basic aspects such as the choice of spaced 0.2 m between plants. species which will compose the system, Soil in the area was classified as the choice of the best arrangement, Red-Yellow Latosol, medium texture The insertion of corn crop between the time of each species planting and (Embrapa, 2014). Soil samples were rows of yacon was due to its low the definition of plant population. collected from the 0-20 cm layer, growth characteristic in the initial phase These aspects are fundamental for which presented the following chemical presented, with emergence from 30 to reaching desired technological levels, and granulometric characteristics 60 days after planting, combined with guaranteeing good yields (Oliveira Filho (Laboratório de Solos, at Centro de a banana orchard in formation stage. et al., 2016). CiênciasAgrárias e Engenharias, UFES): pH (water)= 5.73; phosphorusMehlich1= The soil to cultivate yacon and corn Thus, the authors noticed 34.79 mg dm-3; potassium = 42.0 mg dm-3; was prepared using a rotary hoe (two the possibility of yacon planting calcium = 2.51 cmolc dm-3; magnesium passes). Then, in April, rhizophores intercropped with bananas, when its = 1.38 cmolc dm-3; aluminium = 0.00 weighing approximately 35 g were canopy is more open, allowing the cmolc dm-3; sum of bases = 2,36 cmolc planted in furrows at 10 cm depth. insertion of another species. In addition, dm-3; CTC effective = 2,36 cmolc dm-3; The fertilization of yacon was adapted as yacon has slow initial growth, with an base saturation = 57.34%; total organic according to the recommendation emergency time that can take 30 to 60 carbon = 1%; total nitrogen = 0.1%; sand of Amaya Robles (2002), providing days (Silva et al., 2018), it is possible nitrogen (N), at equivalent dose of to compose a triple intercropping, based 104.37 kg ha-1. The authors used tanned bovine manure, which presented: 15.054 84 g kg-1 nitrogen, 5.996 g kg-1 phosphorus, Horticultura Brasileira 38 (1) January - March, 2020

Yacon planting density in intercropping with corn under banana orchard 8.746 g kg-1 magnesium, 9.098 g kg-1 measurements were carried out at 1 using the formula: CRCA = (IA x 100) calcium and 30.069 g kg-1 potassium. p.m., on clear sky days, again using / IEA and CRCB = (IB x 100) / IEA. In Bovine manure, 160 g, was applied the last pair of fully expanded leaves, addition to these agronomic indicators, per plant at planting and 70 g was and without any visual abnormalities. gross income was calculated (RB = applied top dressing, after 90 days. Corn Photosynthetically active radiation was quantity produced x selling price), planting was performed on the same standardized in artificial saturating light taking into consideration the average day yacon was planted (April, 5) using of 1000 μmol photons m-2 s-1 and CO2 marketing cost of the kilogram of yacon seeds of conventional variety Alvareli, in concentration in a 420 ppm chamber. roots, husked ears and banana tier, from with two fertilizations, one at planting January to July, 2018, at the Supply and another at 20 days after emergence, After evaluating yacon, corn was Centers in the state of Espírito Santo with 50 g m-2 of formulation 04-14-08. harvested (90 DAP) at green corn (Ceasa-ES). stage. Corn biomass was cut and left Three manual hoeings were done on the soil, to be used as mulching. We Data were submitted to variance throughout yacon cycle in order to evaluated diameter, length and weight of analysis (ANOVA) in a scheme of control spontaneous plants. Sprinkler the ears (husked and unhusked), and total subdivided plots. The averages for corn irrigations were performed in order to productivity (t ha-1). Productivity was intercropping were compared using the supplement monthly rainfall, via climate calculated using fresh mass of husked F test (p<0.05) and effect of planting management, and irrigation shift every ears, and productivity in monocrop was densities were compared using Tukey three days, in order to approach 600 estimated based on the data obtained test (p<0.05), by SISVAR software mm required by yacon crop (Grau & from Embrapa (2016). (Ferreira, 2011). Rea, 1997). There was no need for pest and disease control for any of the crops. At 210 days, yacon was harvested RESULTS AND DISCUSSION and its productivity calculated using Solar radiation measurements were the production of tuberous roots per No interaction between densities of performed 90 days after yacon planting, area, according to planting density yacon cultivation and intercropping with with the aid of a radiometer LI-191R in each treatment. For productivity corn was observed, for morphological Line Quantum Sensor, at the top of in yacon monocrop, we calculated and physiological variables at 90 yacon canopy, in both environments IEA considering 39.9 t ha-1 found by DAP. However, significant effect using (with or without corn intercropping). Carvalho (2018), in density of 20,000 intercropping was verified, considering plants per hectare, under the same that yacon plants presented a decrease At 90 days after planting (DAP), climatic conditions. in height, number of leaves and leaf we performed some evaluations in area, when intercropped with corn up the four central plants of the yacon Banana productivity was calculated to 90 DAT (Table 1). We also verified plots. The following morphological using tier weight and cluster emission at significant effect on density only for and physiological characteristics were the end of the first production cycle. The productivity (Table 2). measured: plant height, number of authors considered the intercropping leaves, leaf area, contents of chlorophyll in the two rows along with yacon, and Changes in height, leaf area and a, b and total, net CO2 assimilation rate, monocrops for the lines with no yacon number of flowers of yacon plant stomatal conductance and transpiration planting. occurred due to light restrictions caused rate. by the intercropping with corn (on the Area equivalence index (IEA) was first 90 days of yacon cycle), which Leaf area was obtained with the aid calculated using the relationship between retarded the growth. The same was of rulers, measuring the length along the productivity in the cultivated area observed in yacon cultivated with corn the main leaf vein, from the base to the using the intercropping system and in Peru, where yacon grew slowly in the leaf apex, disregarding the petiole; and in monocrop (Vandermeer, 1990), first three months. Nevertheless, after the width measured perpendicular to using the following formula: IEA = corn harvest, greater plant development the main rib, obtained from one end to (productivity of Crop A in intercropping was observed; which coincided with the other of the leaf. The leaf area was / productivity of Crop A in monocrop) + the vegetative stage and beginning of calculated using the equation Â������CL= (productivity of Crop B in intercropping tuberization of rapid growth roots of -27.7418+ (3.9812CL/lnCL), in which / productivity of Crop A in monocrop). yacon (Seminário et al., 2003). C is the length and L the width of the According to Vandermeer (1990), leaf, developed by Erlacher et al. (2016). intercropping is considered efficient, in Morphological characters also vary relation to monocrop, when the value of according to environmental (water, Chlorophylls contents were IEA is superior to 1.00. light, temperature) and cultural factors determined with the aid of (such as planting density) (Amaya ClorofiLogFalker model FL103, at We also calculated the Relative Robles, 2002). 8 a.m., using the last pair of fully Contribution of Crops (CRC) to IEA, expanded leaves. which is a derivative of the ratio between Most of the time shaded plants are Individual Relative Productivity (IA and higher than non-shaded ones (Han et al., Net CO2 assimilation rate, stomatal IB) and the total IEA of the system, 2015), almost always due to etiolation; conductance and transpiration rate showing the percentage of participation were determined using an infrared gas of each crop in obtaining the total index, 85 reader (IRGA Licor 6800XT). The Horticultura Brasileira 38 (1) January - March, 2020

AG Teixeira et al. no response for yacon in intercropping Lower stomatal conductance resulted (Pereira Filho et al., 2015), diameters was verified, though. However, a in the lower rate of transpiration, were superior to 3 cm, showing that no decrease in growth in relation to less demonstrating that the plants would produced ear quality was lost. radiation incident on the plant was be in an unfavorable condition, which noticed. would limit the opening of stomata, Light restriction condition decreases resulting in less conductance of these the leaf photosynthetic rates (Yang Generally the small amount of light plants and making it difficult to maintain et al., 2018), promoting lower net provides lower levels of chlorophyll the continuous soil-plant-atmosphere. photosynthesis rates, which may affect “a”, “b” and total in plants in relation to This may lead to inefficiency of electron the development and production of some the plant in full sun (Yang et al., 2018). transporters and in the activity of plants. For yacon/corn intercropping, a However, these responses depend on ribulose-1.5-bisphosphate carboxylase competition for nutrients may probably each plant, as well as restriction intensity / oxygenase, and decrease in the rate have happened when yacon would be in which it is exposed, since some plants of liquid assimilation (Li et al., 2014). mobilizing its reserves for the tuberous can adapt to conditions with some light roots, as it was reported by Silva et restrictions, such as taro (Colocasia The results may be related to the al. (2018): yacon shows increasing esculenta), which produces better under lower efficiency of yacon in increasing investment in the fraction of tuberous 30% light restriction (Oliveira et al., the total dry mass under greater light roots, especially after 60 days after 2011). For sweet potato, the ability to restriction conditions, which is directly planting, and peak investment at 120 develop under light restriction depends related to a lower efficiency in the use of days. on the genetic material, considering light, CO2, water and nutrient resources that some cultivars are more adapted to (Pinzón-Torres & Schiavinato, 2008), This possible competition must have low light intensity conditions (Zhang resulting in a lower development up to been supported by the characteristics of et al., 2018). 90 DAP, when intercropped with corn, corn which is a rapid-growth plant, with under banana orchard. an aggressive root system, and great Some reports state that yacon is nutrient extractor (mainly nitrogen), benefited by a certain level of shading, Corn was harvested at 90 DAP which could have harmed yacon, despite according to Teixeira (2018), 30% to showing corns with 4.2 cm average management conditions and cultural 50% light restriction promote better diameter (husked ear) and 3.8 cm treatment (mainly fertilizations) have growth and development of yacon plant. (unhusked ear), 17.3 cm average length been done according to the needs for (husked ear) and 10.9 cm (unhusked ear), each plant. It has to be considered that The decrease in photosynthetically 4.6 t ha-1 average productivity (husked the corn crop received top dressing active radiation also affected other ear) and 7.6 t ha-1 (unhusked ear). fertilization earlier (at 20 days), which physiological processes, since net CO2 Despite the values of ear length being could have allowed the possible assimilation rate, stomatal conductance below those observed in monocrops, competition between crops, after 60 and transpiration rate were lower in with averages from 16.71 to 19 cm days. yacon intercropped with corn (Table 1). Thus, this fact should be observed Table 1. Averages of plant height, leaf area and number of leaves, chlorophyll a, b and total, when planning an intercropping system net assimilation rate, transpiratory rates and stomatal conductance in yacon plants cultivated to achieve success. Some crops are in intercropping in the absence and presence of corn, under banana orchard, at 90 days after affected by light restriction caused planting. UFES, Alegre, 2017. by other crops, when intercropped, which results in a decrease in growth Corn Height Leaf area Number of and production (Zhang et al., 2018). intercropping (cm) (cm²) leaves However, adaptations of these crops to intercropping need to be studied Absence 35.5 a* 252.05 a 15.72a case by case, since management used in the system also influences. Taro Presence 30.5 b 163.61 b 11.61b plants, for instance, were benefited from intercropping with crotolaria, during the CV (%) 5.89 11.43 5.20 first 120 days in the cycle; permanent intercropping with crotolaria was Chlorophyll “a” Chlorophyll “b” Total chlorophyll harmful to this plant, though (Oliveira et al., 2007). 28.64a 8.41a 37.41a Thus, we should observe that 24.70b 6.52b 31.58b the performance of yacon/corn intercropping, under banana orchard, CV (%) 4.71 11.96 5.20 is efficient for income generation to the farmer. The area equivalence index A (μmol CO2 m-2 s-1) E (mmol H2O m-2s-1) gs(mol H2O m-2 s-1) (IEA) was 1.23 (value from which intercropping system is considered 8.63a 4.67a 0.400a 5.62b 3.12b 0.267b CV (%) 32.82 15.00 25.03 Averages followed by same letters did not differ significantly by F test, 5% probability; A= net assimilation rate; transpiratory rates (E) and stomatal conductance (gs). 86 Horticultura Brasileira 38 (1) January - March, 2020

Yacon planting density in intercropping with corn under banana orchard Table 2. Area equivalence index, relative contribution of crops and gross income of yacon cultivation under banana orchard. UFES, Alegre, 2017. Spacings Productivity IEA2 CRC3 (%) Gross income (R$)4 (t ha -1) Yacon Banana Yacon Banana Total 0.3 m 6.47a1 1.16 13.7 86.3 8,057.50 27,400.004 35,457.50 0.4 m 6.09a 1.15 13.4 86.6 7,612.00 27,400.00 35,012.00 0.5 m 2.79b 1.07 6.5 93.5 3,487.50 27,400.00 30,885.50 CV (%) 30.08 1Averages followed by same letters in the column did not differ significantly by F test, 5% probability. 2Area equivalence index (IEA); 3Relative contribution of crops (CRC). 4Calculus based on R$1.25 kg-1 of yacon roots and on R$1.37 kg-1 of banana tier, which were the average values commercialized from January to July, 2018 at Centrais de Abastecimento do Espírito Santo (Ceasa-ES). efficient to be used), it means, superior planting densities under banana orchard, noticed that higher productivity, with to 1.0 showing that yacon/corn the authors noticed that spacings 0.3 and higher CRC, was obtained using yacon intercropping increase the efficiency 0.4 m were the ones which promoted in spacings 0.3 and 0.4 m, provided in using the area, despite the decrease higher productivities (6.47 and 6.09 t ha-1, higher gross income using intercropping in yacon productivity 3.91 t ha-1 in the respectively), this is related to greater in these densities. Thus, for a banana presence of corn, less than in the absence number of plants per area (Table 2). farmer who also aims yacon market, of 6.25 t ha-1. the intercropping is also interesting, Generally, yacon productivity considering using double rows to plant We calculated the Relative obtained under banana orchard can be yacon, alternating between the rows Contribution of Crops (CRC) in yacon/ considered lower than expected, since of banana, mainly in 0.3 and 0.4 m corn intercropping based on R$1.25 kg-1 the higher density of the plant tested spacings. of yacon roots and R$1,33 kg-1 of husked in this system (11,111 plants ha-1) ear, which were the average values was around 50% in relation to density The authors highlight that banana commercialized from January to July usually used in monocrop (20,000 plants crop was not affected by yacon crop, (2018) at Centrais de Abastecimento ha-1) and presented around 21% of the presenting an average productivity of 20 do Espírito Santo (the main supply productivity observed in monocrops (30 t ha-1 (in first generation plants, mother center in the state of Espírito Santo, t ha-1) (Silva et al., 2018). plants), 12.42 kg cluster weight, 1.6 Ceasa-ES). The authors noticed that kg tier weight, 144 g fruit weight, 8.73 corn contributes in 51.3% more than Using these values of productivity of tiers/cluster, 14.05 fruits/tier, and 14- yacon, with 48.7%, due to a good crop yacon and banana, IEA was estimated in cm length and 40-mm diameter fruits. yield in the intercropping (7.6 t ha-1). the three spacings of yacon cultivation, These characteristics are within market This greater contribution of corn will considering that all the values were classification standard (HorteBrasil, reflect in the gross income obtained in higher than 1.0 (reference value), 2018). Moreover, banana productivity, the intercropping system, compensating showing that yacon planting system in general, was above average in Espírito for decrease in productivity noted with under banana orchard was efficient in Santo (7.8 t ha-1) (Incaper, 2017). yacon. That is why, the intercropped use of the area, in all used spacings areas showed better gross incomes, (Table 2). IEA results showed that Taking into consideration that banana R$8060.00, in relation to areas without intercropping with yacon grown in crop is one of Capixaba agribusiness intercropping, R$4885.00, showing that double rows (between alternating activities, showing great social and although intercropping is detrimental banana plant rows) optimizes the use economic importance, generating over to yacon productivity, corn yield can of the area in 16, 15 and 7%, in yacon 25 thousand jobs mostly family-based financially compensate. spacing of 0.3 m; 0.4 m and 0.5 m, farmers, yacon insertion intercropped respectively. with banana orchard can be a viable Considering this fact, for a strategy, extra income for family farmer who aims to grow yacon, this Also, Relative Contribution of Crops farmers, contributing to their food and intercropping is not interesting, since (CRC) to IEA in yacon intercropping financial sovereignty. yacon shows a decrease in productivity under banana orchard (in each density) when intercropped with corn. However, was calculated. The authors noticed Yacon development and production for a farmer who aims to grow corn, that banana is the crop which most were harmed by corn intercropping corn intercropping in the initial phase contributes, which was expected, since (under banana orchard), regardless yacon of yacon cycle (90 first days of cycle) it is the main crop; yacon also generates spacing used. Yacon-corn intercropping can be convenient, as the extra income contributions for intercropping, around increased area use efficiency and, in offered by corn makes intercropping 13%, when planted in spacings 0.3 and relation to a greater relative contribution more profitable. 0.4 m, though (Table 2). of crop to intercropping and its market value, the system generated higher gross Observing the effect of yacon Observing monetary income of the income, showing that despite harming intercropping (gross income, R$), we 87 Horticultura Brasileira 38 (1) January - March, 2020

AG Teixeira et al. yacon productivity, it is still profitable EMPRESA BRASILEIRA DE PESQUISA 2008. Crescimento, eficiência fotossintética e for the farmer. AGROPECUARIA – EMBRAPA, 2016. eficiência do uso da água em quatro espécies Available at <https://www.embrapa.br/busca- de leguminosas arbóreas tropicais. Hoehnea Yacon planting, under banana de-noticias/ /noticia/14977137/produtores-de- 35: 395-404. orchard, optimizes the use of the area milho-verde-avaliam-cultivar-da-embrapa>. (around 15%), being profitable to the Accessed May 10, 2018. PEZZOPANE, JEM; CASTRO, FS; PEZZOPANE, farmer, especially when the yacon is JRM; CECÍLIO, RA. 2012. Agrometeorologia: planted in double rows, alternating FERREIRA, DF. 2011. Sisvar: a computer aplicações para o Espírito Santo. Alegre: between the rows of the banana tree, in statistical analysis system. Ciência e CAUFES. p.174. 0.3 and 0.4m spacings. Agrotecnologia, Lavras: UFLA. 6: 1039-1042. SACRAMENTO, SM; SILVA, PSRC; TAVARES, ACKNOWLEDGMENTS INSTITUTO CAPIXABA DE PESQUISA, MIB. 2017 Batata yacon alimento funcional. ASSISTÊNCIA TÉCNICA E EXTENSÃO Semioses 11: 43-48. The authors are grateful to FAPES RURAL – INCAPER. 2017. Available at (Research Support Foundation of https://biblioteca.incaper.es.gov.br. Accessed SEAPA - Secretaria de Estado de Agricultura, Espírito Santo) and CNPq (National March 30, 2018. Pecuária e Abastecimento. 2017. Available at Council for Scientific and Technological <http://www.agricultura.mg.gov.br/relatorios/ Development) for their financial GRAU, A; REA, J. Yacon Smallanthus agricultura>. Accessed March 05, 2018. support and granting scholarships and sonchifolius (Poepp. & Endl.) H. Robinson. research. To CAPES (Coordination In: HERMANN, M; HELLER, J (eds). 1997. S E M I N A R I O , J ; VA L D E R R A M A , M ; for Improvement of Higher Education Andean roots and tubers: Ahipa, arracacha, MANRIQUE, I. 2003. El yacon: fundamentos Personnel) for doctorate scholarship to maca and yacon. Promoting the conservation para el aprovechamiento de un recurso the first author. and use of underutilized and neglected crops. promisorio. Lima: CIP, Universidad Nacional Rome: IPK. Gatersleben / IPGRI, p.199-256. de Cajamarca,Agencia Suiza para el Desarrollo REFERENCES y la Cooperación (COSUDE). HAN, S; JIANG, J, LI, H; SONG, A; CHEN, AMAYA ROBLES, JE. 2002 Desenvolvimento de S; CHEN, F. 2015. The differential response SILVA, DMN; OLIVEIRA, FL; CAVATTE, yacón (Polymnia sonchifolia Poep. & Endl.) of two chrysanthemum cultivars to shading: PC; QUARESMA, MAL. 2018. Growth and A partir de rizóforos e de gemas axilares, em photosynthesis, chloroplast, and sieve element- development of yacon in different periods of diferentes espaçamentos. Botucatu: UNESP. companion cell ultrastructure. HortScience 50: planting and grow in regions. Acta Scientiarum 110p. (Ph.D. thesis). 1192-1195. Agronomy 40: 39442. ARAÚJO, AV; PARTELLI, FL; OLIVEIRA, HORTEBRASIL. 2018. Available at <http:// TEIXEIRA, AG. 2018. Cultivo de yacon em MG; PEZZOPANE, JRM; FALQUETO, www.hortibrasil.org.br/classificacao/banana>. ambientes sombreados. Alegre: UFES. 64p. AR; CAVATTE, PC. 2015. Microclima e Accessed April 23, 2018. (Ph.D. thesis). crescimento vegetativo do café conilon consorciado com bananeiras. Coffee Science LI, T; LIU, LN; JIANG, CD; LIU, YJ; SHI, TOMAZINI, R; CAMARGO, JT; CASTIGLIONI, 10: 214-222. L. 2014. Effects of mutual shading on the SAC; OLIVEIRA, AJ; OLIVEIRA, EMB; regelation of photosynthesis in field-grown VIRGOLINO, VPB; GAVAZZONI, EC; CARVALHO, AH. 2018. Arranjos populacionais sorghum. Journal of Photoch Photobio, 137: L A N G E R , L F ; V I L L A N O VA , A C C ; para o cultivo de yacon. 2018. Alegre: UFES. 31-38. CASTIGLIONI, GL. 2009. Sombreamento 82p. (Ph.D. thesis). na produção de folhas e raízes de yacon OLIVEIRA, FL; SILVA, DMN; QUARESMA, (Smallanthus sonchifolius Poep. & Endl.) ERLACHER, WA; OLIVEIRA, FL; FIALHO, MAL. 2013. Yacon: potencial como hortaliça. H. Robinsón. Available at http://www. GS; SILVA, D; CARVALHO, AH. 2016. In: Tópicos especiais em produção vegetal abhorticultura.com.br. Accessed April, 18, Modelos para estimar a área foliar do yacon. IV.1 ed. Alegre: CAUFES, p. 502-529. 2018. Horticultura Brasileira 34: 422-427. OLIVEIRA, FL; ARAUJO, AP; GUERRA, JGM. VILLAMIZA, LB; MOSQUERA, NH; PIÑEROS, EMPRESA BRASILEIRA DE PESQUISA 2011. Crescimento e acumulação de nutrientes ALM; MUÑOZ, PB; OSPINA, LMP. 2014. AGROPECUARIA - EMBRAPA. 2014. em plantas de taro sob níveis de sombreamento Yacon (Perú), Jímaca (Colombia) Smallanthus Centro Nacional de Pesquisa de Solos. Sistema artificial. Horticultura Brasileira 29: 291-298. sonchifolius. Fundación Universitaria Juan N. Brasileiro de Classificação de Solos. 2.ed. Rio Corpas Escuela de Medicina, Bogotá 32p. de Janeiro: Embrapa Solos. 306p. OLIVEIRA, FL; GUERRA, JGM; RIBEIRO, RLD; ALMEIDA, DL; URQUIAGA, S; VANDERMEER, JH. 1990. Intercropping. EMPRESA BRASILEIRA DE PESQUISA ESPÍNDOLA, JAA. 2007. The use of In: GLIESSMAN, SR (ed). Agroecology: AGROPECUARIA - EMBRAPA. 2012. sunnhemp as green manure intercropped with researching the ecological basis for sustainable Embrapa Mandioca e Fruticultura. Banana, taro. Horticultura Brasileira 25: 562-566. agriculture 481-516. o produtor pergunta, a Embrapa responde. 2ª ed. revista e ampliada, 174p. OLIVEIRA FILHO, AF; BEZERRA, FTC; YANG, F; FENG, L; LIU, Q; WU, X; FAN, PITOMBEIRA, JB; DUTRA, AS; BARROS, Y; RAZA, MA; LIU, W. 2018. Effect of GL. 2016. Eficiência agronômica e biológica interactions between light intensity and red-to- nos consórcios da mamoneira com feijão- far-red ratio on the photosynthesis of soybean caupi ou milho. Revista Ciência Agronômica leaves under shade condition. Environmental 47: 729-736. and Experimental Botany 150: 79-87. PEREIRA FILHO, IA; CRUZ, JC; SILVA, AR; ZHANG, D; DU, G; SUN, Z; BAI, W; WANG, COSTA, RV; CRUZ, I. 2015. Milho verde. Q; FENG, L; YANG, N. 2018. Agroforestry Agência Embrapa de Informação Tecnológica. enables high efficiency of light capture, Embrapa. Available at http://www.agencia. photosynthesis and dry matter production cnptia.embrapa.br//milhoverde. Accessed in a semi-arid climate. European Journal of May 19, 2018. Agronomy 94: 1-11. PINZÓN-TORRES, JA; SCHIAVINATO, MA. 88 Horticultura Brasileira 38 (1) January - March, 2020

Research ANDRADE JÚNIOR, VC; OLIVEIRA, AJM; GUIMARÃES, AG; FERREIRA, MAM; CAVALCANTI, VP; FERNANDES, JSC. 2020. Repeatability and heritability of production characters in strawberry fruits. Horticultura Brasileira 38: 89-93. DOI - http://dx.doi.org/10.1590/S0102-053620200114 Repeatability and heritability of production characters in strawberry fruits Valter C Andrade Júnior 1 ;ID Altino JM Oliveira 1 ;ID Amanda G Guimarães 2 ;ID Marcos Aurélio M Ferreira 2 ;ID Vytória P Cavalcanti 1 ;ID José Sebastião C Fernandes 2ID 1Universidade Federal de Lavras (UFLA), Lavras-MG, Brasil; [email protected]; [email protected]; vytoriapc@yahoo. com.br; 2Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina-MG, Brasil; [email protected]; [email protected]; [email protected] ABSTRACT RESUMO The estimation of repeatability coefficient provides support to Repetibilidade e herdabilidade de caracteres de produção define the number and the appropriate period of genotype evaluations, nos frutos do morangueiro obtaining better success in breeding programs, in order to lower labor costs. Therefore, knowing repeatability and heritability parameters is A estimativa do coeficiente de repetibilidade possibilita auxiliar relevant. Thus, the aim of this study was to estimate the repeatability na definição do número e no período adequado de avaliações dos and heritability coefficients and accurately determine the number genótipos obtendo melhor êxito em programas de melhoramento, afim of measurements. Eight strawberry cultivars were analyzed in a de ocasionar menor custos de mão-de-obra. Dessa forma, é relevante o randomized block design with four replicates and eighteen plants per conhecimento de parâmetros de repetibilidade e herdabilidade. Assim, plot, being harvested twice a week over a period of six months (May o objetivo do trabalho foi estimar o coeficiente de repetibilidade e to October, 2012), totalizing six evaluations. Among the evaluated herdabilidade e determinar o número de medições com a precisão traits, the estimated heritabilities ranged from 3.13% (number of desejada. Para isso, oito cultivares de morangueiro foram analisadas fruits) to 40.20% (average fruit mass) whereas the repeatability em delineamento em blocos casualizados com quatro repetições e ranged from 9.00 to 42.06% for the same characters. The minimum dezoito plantas por parcela, sendo a colheita realizada duas vezes number of evaluations, to reach a coefficient of determination with por semana em um período de seis meses (maio a outubro de 2012), an accuracy of about 80%, ranged from the maximum of 40 for fruit considerando então seis avaliações. Entre os caracteres analisados, number and the minimum of 6 for average fruit mass. In order to be as herdabilidades estimadas variaram de 3,13% (número de frutos) considered commercially important marketable fruit mass, minimum a 40,20% (massa média de frutos) ao passo que as repetibilidades of 20 evaluations are required, it means, at least, 20 months. variaram entre 9,00 e 42,06%, para os mesmos caracteres. O número mínimo de avaliações para se atingir um coeficiente de determinação com 80% precisão variou entre o máximo de 40 para o caráter número de frutos e o mínimo de 6 para o caráter massa média de frutos. Para o caráter considerado mais importante do ponto de vista comercial (massa comercial de frutos) há necessidade de pelo menos 20 avaliações para se atingir a referida determinação, ou seja, pelo menos um ano e oito meses. Keywords: Fragaria x ananassa, genetic breeding, number of Palavras chave: Fragaria x ananassa, melhoramento genético, measurements. número de medições. Received on May 7, 2019; accepted on November 22, 2019 Strawberry crop (Fragaria x In order to overcome the barriers should be made on each character, to ananassa) is very appreciated to the selection of the most productive confirm data authenticity, achieving high by consumers since its sensory and cultivars with good-fruit quality productivity and avoiding production nutritional characteristics are very (Guimarães et al., 2015; Mishra et al., costs. Repeatability coefficient is used well defined (Guimarães et al., 2016), 2015), attaining information on the as statistics parameter (Cargnin, 2016); it is also a highly valued crop for in number of harvests which are necessary it is defined as the correlation between natura commercialization as well as to obtain superior cultivars in shorter measurements of a given character in the for industrial processing (Guimarães time, lowest costs of labor and resources same individual, whose measurements et al., 2014). The cultivation demands is essential (Azevedo et al., 2016). were repeated in time or space (Cruz et skilled labor from cultural practices up al., 2012). Additionally, repeatability to harvest which are performed more Thus, using statistical procedures, expresses the maximum limit that in than once a week during fruit ripening it is possible to evaluate production a broad sense can be achieved, being (Henz, 2010; Ronque et al., 2013). characteristics of each harvest in order to heritability the explanation of the predict how many accurate observations Horticultura Brasileira 38 (1) January - March, 2020 89

VC Andrade Júnior et al. proportion of phenotypic variance area. j harvests of i genotypes; µ= overall which is attributed to genetic differences average; gi= effect of i genotypes (i= confused with the environmental effects Strawberry seedlings were planted 1, 2, ..., 8 individuals); mj= effect of on the cultivar (Cruz et al., 2012). on March 1, 2012 under a low tunnel measurement (j= 1, 2, 3, 4, 5 and 6); system, covered with 75 micron rk= effect of repetition (k= 1,2,3 and 4); Repeatability coefficient has been thickness plastic, 0.80 m height from gmij= interaction between genotypes estimated for many species, mainly the the seedbed surface. Soil was also and measurement; grik= interaction perennial ones such as grape (Sales et covered with white plastic, 30 micron between genotypes and repetition; mrjk= al., 2019) and semi- perennial such as (mulching), measuring 0.20 height, 64 interaction between measurement and sugar cane (Silva et al., 2018). However, m length and 1 m width. Fertigation repetition; gmrijk= triple interaction this coefficient can also be estimated was sprinkler irrigated and cultural or random residue between genotype, for annual vegetable species in which practices were carried out according to measurement and repetition. Effects several harvests are performed in a the recommendations for the crop. of gmij are permanent environmental same cycle, as kale (Azevedo et al., effects, from one harvest to another. 2016), tomato (Adewale & Adebo, Harvest began 60 days after seedling 2018), bell pepper (Pimenta et al., planting when fruits showed 75% Using the expected average 2016) and cucumber (Cardoso, 2006). ripening, being performed twice a week squares in variance analysis (Box 1), For strawberry crop, no reports can during six months (May-October, 2012), repeatability coefficient (ρ) (equation be found in relation to this parameter, considering six evaluations, totalizing 1) and heritability (h²) (equation 2) were which makes estimation necessary, since 48 harvests. estimated: several harvests are carried out per cycle in the same plant. Evaluated characteristics , (equation 1) Considering that no information Fruits were taken to Laboratório In which = the variance among was found on the number of evaluations de Tecnologia Biomassa do Cerrado, cultivars; = genotypic variance and which are necessary for agronomic of Universidade Federal dos Vales do repetition; = permanent phenotypic characteristics in selective processes Jequitinhonha e Mucuri, at Campus variance among plants, which means, on strawberry crop, this study aimed to JK, in Diamantina-MG, being counted genotypic and permanent environment estimate the repeatability and heritability and weighed. Strawberries with mass from one harvest to another. coefficients and accurately determine the superior to 10 grams were classified as number of measurements for predicting suitable to be commercialized in natura , (equation 2) strawberry crop performance. (Guimarães et al., 2015). The following characteristics were evaluated: a) In which = variance among cutivars MATERIAL AND METHODS average mass of total fruits (MMFT) = phenotypic variance. and average mass of marketable fruits The number of measurements (Ƞ0) Eight strawberry cultivars were (MMFC), obtained through production used, considering that six were short- per plant and number of fruits ratio, (equation 3) necessary to predict the day cultivars (Festival, Camarosa, both expressed in g fruit-1; b) number of real value of individuals, based on Campinas, Toyonoka, Dover and Oso total fruits (NFT) and marketable fruits appropriate coefficient of determination Grande) and two neutral-day ones (NFC) in each harvest, counting per (R2) (minimum of 80%), was calculated (Aromas and Diamante). The matrices experimental unit and expressed in fruit according to Cruz et al. (2012): were obtained from Multiplanta plant-1; c) total productivity (PT) and Biotecnologia Vegetal Ltda. marketable productivity (PC), counting (equation 3) in each harvest month, fruit production Environment and experimental of each plot of each cultivar, expressed In which R2= represents the percentage design in t ha-1; d) length (COMP) and diameter of prediction of actual value of selected (DIAM) of the fruit being measured in individuals, based on Ƞ obtained by The experiment was carried out at longitudinal and transversal directions equation (4): the Farm of Mape Frutas Ltda., located of the fruit, respectively, using a digital in the municipality Datas-MG (18º26’S, caliper (Digital Caliper 0-15 cm). Three (equation 4) 43º39’W, altitude 1,244 m). The climate strawberry fruits were evaluated per of the region is humid tropical, Aw, plot, in each cultivar in each harvest RESULTS AND DISCUSSION according to Köppen classification, with and the results expressed in millimeters dry winter and rainy summer. The soil (mm). Analysis of variance revealed was classified as Quartzarenic Neosol. significant differences (P<0.05) for Statistical analysis most evaluated variables, except for We used a randomized block design, effect of blocks (Table 1). These results with eight strawberry cultivars, four The analyses were performed using showed variability among the evaluated replicates and eighteen plants per plot, complete repeatability statistical model genotypes, corroborating that the genetic spaced 0.30 x 0.30 m, and 2 m2 useful (Resende, 2006), Yijk = µ + gi + mj + component of variance, confused with rk+ gmij+ grik+ mrjk + gmrijk, in which permanent environmental effects, is Yijk= observations of k repetitions of significant (Manfio et al., 2011). 90 Horticultura Brasileira 38 (1) January - March, 2020

Repeatability and heritability of production characters in strawberry fruits Average repeatability values were High repeatability coefficient characteristics are quite influenced by estimated (0.30<ρ<0.60) based on (ρ>0.60) would show cultivar stability, environmental variations, which should the classification of repeatability genetic control and an accurate increase the number of measurements coefficients in relation to the magnitude evaluation of phenotypic values, which suitable to express the accuracy gain (Resende, 2002). In this study the would facilitate the development of of the real value of individuals, or the repeatability coefficients of the eight breeding studies, since it would assume genetic difference among cultivars, studied characters showed indexes that the largest proportion of the total since they were differentiated in varying from ρ= 0.09 (total fruit number) variation could be inherited by the photoperiods (short and neutral) which to ρ= 0.42 (average mass of total fruit) next generation with the possibility may differentiate in manifestation of its (Table 3). of adopting massal selection with potential. greater reliability of results (Cruz et Values for MMFT (0.42), COMP al., 2012). However, low repeatability Oliveira & Fernandes (2001), (0.39) and DIAM (0.34) showed average values obtained in these characteristics estimating repeatability coefficient regularity of character repetition, from showed that no uniformity of measuring for characters of açaí bunch, for total one cycle to the other, considering the character from one harvest to the weight, fruit weight, number of fruits being satisfactory values. Repeatability other could be noticed. This fact shows and fruit yield also showed repeatability values for other characteristics were greater difficulty in identifying more coefficient with low magnitudes low (ρ≤0.30) MMFC (0.16), PT (0.16), productive and stable plants throughout (p≤0.30). The highest repeatability and PC (0.22), NFT (0.08) and NFC (0.20), their productive life. determination coefficients were obtained which makes us suggest more number for average mass of fruits. These authors of evaluations for more accurate results The unevenness in measurement determined that average fruit mass can (Table 2). between harvests shows that the be used as a parameter for selection in less rigorous breeding methods, as Box 1. Analysis of variance of strawberry cultivars evaluated from May to October, 2012 repeatability coefficient expresses the from the municipality of Datas-MG (Mape Frutas Ltda. Farm) (M= measurements; B= blocks; maximum broad-sense heritability G= genotypes; QM= average square of measurements; QB= average square of block; QG= values. However, the desirable number average square of genotypes; QMxB= average square of measurements/blocks; QGxM= average of measurements for this character square of genotype/QGxB= average square of genotypes/blocks; QGxMxB= average square of should be almost three times the one genotype/blocks). Diamantina, UFVJM, 2017. used by the authors. Variation source GL QM E(QM) Estimated heritability values of this Measurements study can be classified as median (15 to Blocks 5 QM σ2gmb+ Iσ2mb+ Kσ2mb + IKσ2m 50%) or low values (1 to 15%) according Genotypes 3 QB to Resende (1995). The group considered MxB σ2 + Iσ2mb + Jσ2gb + IJσ2b of median characteristics is represented GxM gmb by MMFT (40.20%), MMFC (15.82%), GxB COMP (29.97%), DIAM (31.10%) GxMxB 7 QG σ2 + Kσ2gm + Jσ2gb + JKσ2g and PC (18.05%) and the low group gmb was represented by PT (7.92%), NFT (3.13%) and NFC (13.56%) (Table 15 QMxB σ2gmb+ Iσ2mb 3). These reduced heritability values are related to the fact that most of the 35 QGxM σ2gmb+ Kσ2gm 21 QGxB σ2gmb+ Jσ2gb 105 QGxMxB σ2 gmb Table 1. Analysis of variance of production variables and their respective probabilities of significance P (F) for average total fruit mass (MMFT), average marketable fruit mass (PMFC), length (COMP), diameter (DIAM), total productivity (PT), marketable productivity (PC), number of total fruits (NFT), number of marketable fruits (NFC) of strawberry cultivars (Fragaria x ananassa) analyzed from May to October, 2012 from the municipality of Datas-MG (Farm of Mape Frutas Ltda.). (M= measurements; R= repetition; B= blocks; G= genotypes). Diamantina, UFVJM, 2017. Variation source GL MMFT MMFC COMP DIAM PT PC NFT NFC Measurements 5 0.000 0.003 0.000 0.000 0.000 0.000 0.001 0.000 Block 3 0.254 0.980 0.272 0.717 0.049 0.018 0.088 0.034 Genotypes 7 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 MxB 5 0.003 0.296 0.043 0.040 0.004 0.101 0.003 0.023 GxM 5 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 GxB 21 0.106 0.365 0.000 0.010 0.000 0.001 0.000 0.000 GxMxB 105 Total 151 Horticultura Brasileira 38 (1) January - March, 2020 91

VC Andrade Júnior et al. phenotypic variation observed was studying different strawberry cultivars genetic materials, the environment itself influenced by the environment, in other in Lavras-MG, found heritability values interferes in the expression of the words, controlled by several genes (Lira for MMFT (75.66%) above this study, characteristics. Júnior et al., 2014). Vieira et al. (2017), which shows that, besides being different Estimated heritabilities showed an Table 2. Estimation of repeatability coefficient (ρ) and estimation of heritability (h²), number interval between 3.13% (number of of measurements (η) and estimation of determination coefficient (R²= 80%) for average total fruits) and 40.20% (average mass mass of total fruits (MMFT), average mass of marketable fruits (MMFC), length (COMP), of total fruits) (Table 2), showing that diameter (DIAM), total productivity (PT), marketable productivity (PC), number of total fruits estimates were always lower than the (NFT), number of marketable fruits (NFC), of strawberry cultivars (Fragaria x ananassa), repeatability coefficient, according to analyzed from May to October, 2012 from the municipality of Datas-MG (Farm of Mape Resende (2002), broad-sense heritability Frutas Ltda.). Diamantina, UFVJM, 2017. is always lower than the repeatability coefficient. Repeatability represents Variables ρ h² η R² the maximum value that the broad- MMFT 42.06% 40.20% 6 (5.50) 81.33% sense heritability can reach (Cruz et MMFC 16.87% 15.82% 20 (19.70) 54.90% al., 2012). Being the difference between COMP 39.80% 29.97% 6 (6.04) 79.86% repeatability and heritability, due to the DIAM 34.85% 31.10% 7 (7.47) 76.24% fact that the genotypic variance used to PT 16.03% 7.92% 21 (20.94) 53.40% estimate repeatability is not only related PC 22.89% 18.05% 13 (13.47) 64.04% to genetic origin, since the permanent NFT 8.99% 3.13% 40 (40.47) 37.22% environmental variance components NFC 20.74% 13.56% 15 (15.28) 61.09% among individuals are still confused with genotypic variance (Azevedo et al., Table 3. Number of measurements required (η) associated with different determination 2016). Thus, repeatability approaches coefficients (R²) estimated from May to October, 2012 for average total fruit weight heritability when variance provided (MMFT), average marketable fruit weight (MMFC), length (COMP), diameter (DIAM), by permanent environmental effects total productivity (PT), marketable productivity (PC), total fruit number (NFT), marketable is minimized (Cruz et al., 2012), it fruit number (NFC) of strawberry cultivars (Fragaria x ananassa) analyzed from May to means, if the variance estimated was October, 2012 from the municipality of Datas-MG (Farm of Mape Frutas Ltda.). Diamantina, only of genetic nature, repeatability UFVJM, 2017. and heritability coefficients would be corresponding (Lopes et al., 2001). Variables R² (%) η Variables R² (%) η As heritability showed low estimate MMFT 80 5.50 MMFC 80 19.70 values, the phenotypic value becomes an COMP 85 7.80 DIAM 85 27.92 unreliable measure of genotypic value, PT 90 12.39 PC 90 44.34 whose apparent relative superiority may NFT 95 26.16 NFC 95 93.61 not be due to the genetic cause. Thus, the 99 136.33 99 487.80 increase of number of measurements, 80 6.04 80 7.47 minimizing environmental influence or 85 8.57 85 10.59 adding greater genetic variability may 90 13.61 90 16.82 result in increased accuracy. 95 28.73 95 35.51 99 149.73 99 185.03 The number of measurements 80 20.93 80 13.47 performed for one R² of 80% accuracy 85 29.66 85 19.08 is considered appropriate according to 90 47.11 90 30.31 Resende (2002) and Souza Sobrinho 95 99.45 95 63.99 et al. (2010). Thus, the number of 99 518.21 99 333.44 evaluations performed in this study (six 80 40.46 80 15.28 months) was sufficient for two variables: 85 57.32 85 21.65 MMFT and COMP showed number of 90 91.04 90 34.39 measurements possible to be performed 95 192.21 95 72.60 (six months). (Tables 2 and 3). 99 1001.53 99 378.30 The other characters evaluated in this study showed measurements of high number, and over eight months of evaluation is necessary to confirm data authenticity with 80% certainty. The authors observed that for the most important character for commercialization and for being 92 Horticultura Brasileira 38 (1) January - March, 2020

Repeatability and heritability of production characters in strawberry fruits directly related to the size (average support for this study. This project MANFIO, CE; MOTOIKE, SY; SANTOS, CEM; mass of marketable fruit), at least 20 was supported by Coordination of PIMENTEL, LD; QUEIROZ, V; SATO, evaluations are necessary to reach this Improvement of Higher Education AY. 2011. Repetibilidade em características determination. Personnel (CAPES) Financing Code biométricas do fruto de macaúba. Ciência 001. Rural 41: 70-76. In order to reach determination levels greater than 90%, the characteristics REFERENCES MISHRA, PK; RAM, RB; KUMAR, N.2015. should be evaluated twice in relation to Genetic variability, heritability, and genetic determination of 80%. There would be ADEWALE, BD; ADEBO, UG. 2018. Phenotypic advance in strawberry (Fragaria × ananassa needed 12 evaluations for average mass identity, similarity and stability for selection Duch.). Turkish Journal of Agriculture and of total fruits, 44 evaluations for average of tomatoes (Lycopersicon esculentum L.) Forestry 39: 451-458. mass of marketable fruits, 14 for length, cultivars in South-western Nigeria. Scientia 17 for diameter, 47 for total production, Horticulturae 235: 264-269. OLIVEIRA, MSP, FERNANDES, GLC. 2001. 30 for commercial production, 91 for Repetibilidade de caracteres do cacho de number of total fruits and 34 for number AZEVEDO, AM; ANDRADE JÚNIOR, VC; açaizeiro nas condições de Belém-PA. Revista of marketable fruits (Table 3). The PEDROSA, CE; VALADARES, NR; Brasileira Fruticultura 23: 613-616. attempting to increase accuracy above ANDRADE, RF; SOUZA, JRS. 2016. Estudo 90% requires an increase in number of da repetibilidade genética em clones de couve. PIMENTA, S; MENEZES, D; NEDER, DG; measurements in relation to accuracy Horticultura Brasileira 34: 54-58. MELO, RA; ARAÚJO, ALR; MARANHÃO, gain, being useless besides making the EAA. 2016. Adaptability and stability of process expensive and time consuming. CARDOSO, AII. 2006. Número mínimo de pepper hybrids under conventional and organic colheitas em pepino híbrido estimado por meio production systems. Horticultura Brasileira To conclude, fruit average mass and do coeficiente de repetibilidade. Bragantia 34: 168-174. length obtained satisfactory number of 65: 591-595. measurements (six evaluations) to predict RESENDE, MD. 1995. Delineamento de their real value, with determination CARGNIN, A. 2016. Repetibilidade e número experimentos de seleção para maximização coefficient of 80%. All the characters de colheita de características para seleção de da acurácia seletiva e do progresso genético. showed estimates of repeatability and clones de variedades viníferas. Ciência. Rural Revista Árvore 19: 479-500. heritability coefficients with low to 46: 221-226. moderate magnitude, showing that RESENDE, MD. 2006. Software Selegen-REML. no regularity in measurements of the CRUZ, CD; REGAZZI, AJ; CARNEIRO, PCS. BLUP. Manual. EMBRAPA. Campo Grande, characters of strawberry fruit production 2012. Modelos biométricos aplicados ao Brasil. 73p. in the determined period was verified. melhoramento genético. Viçosa: UFV, 514p. Thus, low coefficient estimates showed RESENDE, MDV. 2002. Genética biométrica the difficulties, which surely caused GUIMARÃES, AG; ANDRADE JÚNIOR, VC; e estatística no melhoramento de plantas higher costs, concluding that superior or AZEVEDO, AM; GUEDES, TJ; PINTO, perenes. Brasília: Embrapa Informação inferior perform of the cultivars may not NAVD. 2016. Quality of strawberry grown Tecnológica. 975p. be maintained. Thus, another method in Brazilian tropical humid conditions for would be to improve the experimental breeding programs. Fruits 71: 151-160. RONQUE, ERV; VENTURA, MU; SOARES conditions indicating the need for greater JÚNIOR, D; MACEDO, RB; CAMPOS, BRS. environmental control or increasing the GUIMARÃES, AG; ANDRADE JÚNIOR, 2013. Viabilidade da cultura do morangueiro number of repetitions so that selection VC; ELSAYED, AYAM; FERNANDES, no Paraná-BR. Revista Brasileira Fruticultura could be carried out reliably. JSC; FERREIRA, MAM. 2015. Potencial 35: 1032-1041. produtivo de cultivares de morangueiro. ACKNOWLEDGEMENTS Revista Brasileira de Fruticultura 37: 112- SALES, WS; ISHIKAWA, FH; SOUZA, EMC; 120. NASCIMENTO, JHB.; SOUZA ER; LEÃO, The authors thank to Foundation PCS. 2019. Estimates of repeatability for for Research Support of Minas GUIMARÃES, AG, OLIVEIRA, CM, VIEIRA, selection of genotypes of seedless table Gerais (FAPEMIG) and to the G, PINTO, NAVD. 2014. Qualidade físicas grapes for Brazilian semiarid regions. Scientia National Council for Scientific and e químicas de morango passa em diferentes Horticulturae 245: 131-136. Technological Development (CNPq) for embalagens. Engenharia na Agricultura 22: the scholarships granted and financial 306-316. SILVA, HC; ANUNCIAÇÃO FILHO, CJ; BASTOS, GQ; DUTRA FILHO, JA; HENZ, GP. 2010. Desafios enfrentados por SIMÕES NETO, DE. 2018. Repeatibility agricultores familiares na produção de of agroindustrial characters in sugarcane morango no Distrito Federal. Horticultura in different harvest cycles. Revista Ciência Brasileira 28: 260-265. Agronômica 49: 275-282. LIRA JÚNIOR, JS; BEZERRA, EF; MOURA, SOUZA SOBRINHO, F; BORGES, V; LÉDO, RJM; SANTOS, VF. 2014. Repetibilidade FJS; KOPP, MM. 2010. Repetibilidade de da produção, número e peso de fruto em características agronômicas e número de cirigueleira (Spondias purpúrea L.). Revista cortes necessários para seleção de Urochloa Brasileira Fruticultura 36: 214-220. ruziziensis. Pesquisa Agropecuária Brasileira 45: 579-584. LOPES, R; BRUCKNER, CH.; CRUZ, CD; LOPES, MTG; FREITAS, GB. 2001. VIEIRA, SD; SOUZA, DC; MARTINS, IA; Repetibilidade de características do fruto de RIBEIRO, GHMR; RESENDE, LV; FERRAZ, aceroleira. Pesquisa Agropecuária Brasileira AKL; GALVÃO, AG; RESENDE, JTV. 36: 507-513. 2017. Selection of experimental strawberry (Fragaria x ananassa) hybrids based on selection indices. Genetics and Molecular Research 16: 1-11. Horticultura Brasileira 38 (1) January - March, 2020 93

Scientific communication LIMA, SF; JESUS, AA; VENDRUSCOLO, EP; OLIVEIRA, TR; ANDRADE, MGO; SIMON, CA. 2019. Development and production of sweet corn applied with biostimulant as seed treatment. Horticultura Brasileira 38: 94-100. DOI - http://dx.doi.org/10.1590/S0102-053620200115 Development and production of sweet corn applied with biostimulant as seed treatment Sebastião F Lima ;1ID Anderson A Jesus1ID; Eduardo P Vendruscolo2ID; Tabata Raissa Oliveira3 ;ID Maria Gabriela O Andrade4ID; Cátia Aparecida Simon5ID 1Fundação Universidade Federal de Mato Grosso do Sul (UFMS), Chapadão do Sul-MS, Brasil; [email protected]; anderson.jesus@ ufms.br; 2Universidade Estadual de Mato Grosso do Sul (UEMS), Cassilândia-MS, Brasil; [email protected]; 3Nufarm, Chapadão do Sul-MS, Brasil; [email protected]; 4Universidade Estadual Paulista (UNESP), Botucatu-SP, Brasil; gabriela13andrade@hotmail. com; 5Universidade de São Paulo (USP), Piracicaba-SP, Brasil; [email protected] ABSTRACT RESUMO Sweet corn has potential to increase farmer’s income. Thus, Desenvolvimento e produção do milho doce tratado com biostimulants may contribute to increase productivity of sweet bioestimulante corn, being indicated and used in various crops. The objective of this study was to evaluate the effects of applying biostimulant on O milho doce é uma cultura com potencial para aumentar a renda sweet corn crops and to establish the ideal dose aiming to increase de propriedades agrícolas. Dessa forma, os bioestimulantes podem the crop’s agronomic characteristics. The experiment was installed contribuir para o aumento da produtividade do milho doce, sendo in the municipality of Chapadão do Sul-MS and was conducted from indicados e utilizados em diversas culturas. O objetivo deste estudo November 15, 2012 to February 19, 2013. Treatments were composed foi avaliar os efeitos da aplicação do bioestimulante para a cultura do of eight biostimulant doses (0.0, 4.0, 8.0, 12.0, 16.0, 20.0, 24.0 and milho doce e estabelecer a dose ideal para aumentar as características 28.0 mL kg-1 of seeds), arranged in a randomized complete block agronômicas da cultura. O experimento foi instalado no município de design with four replicates. The responses of the variables to the best Chapadão do Sul-MS, e foi realizado de 15 de novembro de 2012 a dose of biostimulant were 12.4, 15.3, 13.7, 12.4, 15.7, 16.4, 15.4 and 19 de fevereiro de 2013. Os tratamentos foram compostos por oito 12.5 mL kg-1, respectively for plant height, first ear insertion height, doses de bioestimulantes (0,0, 4,0, 8,0, 12,0, 16,0, 20,0, 24,0 e 28,0 stem diameter, final population, number of ears per hectare, ear mass mL kg-1 de sementes), dispostas em delineamento em blocos ao acaso, with and without straw and ear index. Considering that the ear with com quatro repetições. As respostas das variáveis à melhor dose de straw is the source of economic return to the producer, the dose of bioestimulante foram 12,4, 15,3, 13,7, 12,4, 15,7, 16,4, 15,4 e 12,5 16.4 mL kg-1 is the best indication in this condition. mL kg-1, respectivamente para altura da planta, altura da inserção da primeira espiga, diâmetro do colmo, população final, número de espigas por hectare, massa de espigas com e sem palha e índice de espigas. Considerando que a espiga com palha é a fonte de retorno econômico ao produtor, a dose de 16,4 mL kg-1 é a melhor indicação nessa condição. Keywords: Zea mays convar. saccharata var. rugosa (sweet corn), Palavras-chave: Zea mays convar. saccharata var. rugosa, phytohormones, growth regulators. fitormônios, reguladores de crescimento. Received on September 10, 2019; accepted on January 24, 2020 Brazil is the third largest producer attributed it to be classified as a special than 13.00 t ha-1 (Luz et al., 2014), the of corn in the world, only after cultivation (Oliveira Junior et al., 2006). technological cultivation conditions China and the United States (FAO, maintain productivity below those 2018). This productive potential implies In terms of land, the world observed in countries such as the USA, that the country also has the necessary area cultivated with sweet corn is with around 17.17 t ha-1 (FAO, 2018). characteristics for producing other approximately 1.04 million hectares. types of corn such as popcorn and those The United States of America is the Provision of appropriate directed to in natura consumption or for country with the largest productive management forms allows the country industrialization. So, sweet corn (Zea area of about 100,000 hectares and an to target higher productivity (Souza mays convar. saccharata var. rugosa) average yield of 8.09 t ha-1 (USDA, et al., 2015, 2016) and the insertion is largely cultivated for the canned 2017). The Brazilian scenario does not of this product into large consumer products industry, almost exclusively for present great popularity for sweet corn, markets. In addition, this scenario human consumption. This characteristic although edaphoclimatic conditions contributes to this species being inserted contribute to a productivity of more in rural properties as an alternative for 94 Horticultura Brasileira 38 (1) January - March, 2020

Development and production of sweet corn applied with biostimulant as seed treatment production diversification, while its happens until the V3 phenological stage used for sowing. Seeds were treated cultivation presents a good profit margin (Magalhães & Durães, 2006). with fungicide (8.5% Thiabendazole + to the producer (Jesus et al., 2016). 35% Thiran) at 200 g per 100 kg seeds. Despite all positive expectations In addition to the necessary with biostimulants and the good results The biostimulant was applied using a improvements in cultural management, obtained from the germination of the graduated pipette directly onto the seeds we seek differentiated strategies that seeds to the growth in height of plants, packed in transparent plastic bags with enable the producer to enter the market observed by Avila et al. (2008) in the 2.0 kg capacity. After application the in a competitive way with higher soybean crop, Ferreira et al. (2007) whole amount was vigorously stirred quality products, but without incurring warn that biostimulants cannot always for two minutes, aiming to standardize productive losses. In this context, be favorable, because they depend on the treatments on the seed mass. introducing biostimulant products several factors such as the plant species, into production systems is seen as an the composition of the product used, Seeds were sown manually, being opportunity, and although there is no among others. sowing and top dressing based on a specific legislation to this group of soil analysis presenting the following products, research is continuously being In light of the above, the objective characteristics: 8.0 mg dm-3 P(mehlich-1); conducted to improve the performance of the study was to evaluate the effects 31.1 g dm-3 M.O.; 4.8 pH (CaCl2); K+, of different crops such as popcorn of applying biostimulant in sweet Ca2+, Mg+2 and H+Al = 0.38; 2.80; (Oliveira et al., 2016) and sweet corn corn cultivation and the proper dose 1.10 and 4.9 cmolc dm-3, respectively, itself (Cunha et al., 2016). establishment aiming to increase and 46.6% base saturation. Liming the crop’s biometric and productive was performed 60 days before sowing, By definition, biostimulants are characteristics. using dolomitic limestone, 75% PRNT, mixtures of one or more growth to raise the base saturation to 60% regulators with other compounds of MATERIAL AND METHODS (Souza & Lobato, 2004). Weeds, pests different chemical nature, such as and diseases were controlled according mineral salts (Castro & Pereira, 2008), The experiment was installed in to the plant breeding recommendation which promote hormonal balance and the municipality of Chapadão do Sul- for cultivating corn. Fertilization for stimulate root growth (Silva et al., 2008) MS, (18º46’18’’S, 52º 37’28’’W, 813 sowing consisted of 30 kg N ha-1, due to action mechanisms, especially m altitude) and was conducted from 120 kg P2O5 ha-1 and 60 kg K2O ha-1, when using products composed by November 15, 2012 to February 19, using urea, simple superphosphate and growth regulators (Taiz et al., 2017). 2013. According to Köppen, the climate potassium chloride fertilizers. For top is tropical humid (Aw), with a rainy dressing, 180 kg N ha-1 and 90 kg K2O In the context of costs related to season in summer and dry in winter, ha-1 were applied, divided into two the production system, it is observed and an average annual rainfall of 1850 applications, when the crop presented that pre-planting treatment with mm with average annual temperatures 4-6 leaves and 8-10 leaves, respectively, biostimulating products is a procedure varying from 13ºC to 28ºC, while the using urea and chloride fertilizers. that barely burdens rural producers experimental area’s soil is classified as Sowing and top dressing were based on (Jesus et al., 2016). This is mainly Oxysoil. recommendations of Souza & Lobato due to the low concentrations of plant (2004). regulators necessary to incur changes in The experimental design was a the physiological plant system (Taiz et randomized block with four replications, The evaluated characteristics were al., 2017). In this way, small increases totaling 32 plots. Each plot was plant height (PH), first ear insertion in productivity are sufficient to cover composed of five lines, five meters height (EH) and stem diameter (SD). the investments for acquiring this in length, spaced at 0.45 m between Height was determined from the ground technology. rows and 0.30 between plants, with a level to the tassel insertion node and to final population of 74,000 plants ha-1, the first ear for PH and EH, respectively. In addition, biostimulant action can featuring a dense sowing for sweet Stem diameter was measured with a tape promote vegetative and reproductive corn. The three central plot lines were measure in the second internode from performance when it is implemented considered useful area. the plant base. in the initial stages due to the developmental characteristics of corn Treatments were composed of All ears of the plot areas were crops, improving the crop’s nutritional eight commercial biostimulant doses harvested manually. The harvest time conditions by developing its root system of Stimulate (0.0; 4.0, 8.0, 12.0, 16.0, was visually determined when green (Cunha et al., 2016) and increasing 20.0, 24.0 and 28.0 mL kg-1 seeds), ears and kernels were in a milky cell division and expansion rates (Taiz composed of three plant regulators in the stadium. The final plant population et al., 2017), provided that optimal following formulation: 0.009% kinetin (POP) was also determined at this doses of the product are implemented. (cytokinin), 0.005% gibberellic acid time, counting the plants in the useful Good nutritional and physiological (gibberiline) and 0.005% indolebutyric plot area, also considering the bedded conditions are determinants for the acid (auxin). and/or broken plants, transforming the crop, considering that determining the population obtained per hectare. productive and vegetative potential Sweet corn GNZ 2004 hybrid was The number of ears (NE) per area Horticultura Brasileira 38 (1) January - March, 2020 95

SF Lima et al. was obtained during harvest, counting reached a minimum of 124.6 cm without The effects on plant vegetative all ears in the useful lines of each plot. biostimulant application (Figure 1A). development are related to the All harvested ears had their masses phytohormone action present in the measured with and without husks after In relation to stem diameter, the dose biostimulant’s composition. Cytokinin harvest. In order to obtain the ear index of 13.7 mL kg-1 applied to the sweet and auxin phytonutrients act on cell (EI), plants were counted in the useful corn seeds provided stems with larger differentiation and on phloem and lines of each plot (number of plants per diameters, reaching a value of 24.3 xylem differentiation, respectively, and plot = NPP) and the total number of ears mm. This maximum dose estimated both act on cell division and stretching per plot (NEP) at the time of harvest. culminated in an increase of 4.89% on these structures, especially in the early The index is generated by the relation the stem diameter (Figure 1B). Higher development stages (Taiz et al., 2017). between these factors (EI = NPP/NEP). yield of corn ears are also positively This promotion of rapid development linked to stem diameter (Table 1), since in the early stages may improve plant Regression analysis was used to it means higher photoassimilate storage establishment and plant growth in later verify the fit of polynomial models for capacity, which are fundamental for stages, since the plant development dependent variables as a function of the developing the grains (Kappes et al., point is below the soil surface up to Stimulate doses applied to the seeds at 2011). the V3 stage, becoming vulnerable to a 5% probability level. abiotic factors such as low temperatures, Stem diameter is a highly relevant lack or excess of water (Magalhães & RESULTS AND DISCUSSION factor during the sweet corn plant cycle. Durães, 2006). In testing 85 different corn genotypes at The biostimulant doses interfered in five sites, Gomes et al. (2010) observed Gibberellins are also important the characteristics of plant height, first that bedding resistance is linked to for the establishment, development ear insertion height and stem diameter, the genotype and the environmental and reproduction of plants. This final plant population, number of ears conditions in which the cultivation is phytohormone is involved in seed per hectare, mass of ears with and conducted. Thus, the increase in stem germination, stem elongation, leaf without husks per hectare, and the ear diameter observed in the present study expansion, pollen maturation and index for sweet corn cultivation (Figures may indicate that these same treatments flowering induction, and the occurrence 1 and 2). have the potential to reduce bedding of levels below adequate levels risk. may result in dwarfism and other There was an increase in the mean physiological deficiencies (Davière & height of sweet corn plants up to the There was also a positive correlation Achard, 2013). Its exogenous application dose of 12.4 mL kg-1, reaching 234.6 cm. between other evaluated characteristics can alleviate the deleterious effects of Compared to the control treatment this (Table 1). This fact implies the need the environment, allowing the plants to maximum dose obtained increase plant to maintain better values for these maintain vegetative and reproductive height in 4.24%. Similar behavior was characteristics in the plant in order to development even in adverse conditions verified for the first ear insertion height, obtain higher yields. In addition to the (Hamayun et al., 2010; Sakata et al., where a dose of 15.3 mL kg-1 enabled direct effect of stem diameter on yield, 2014; Khan et al., 2015), resulting an the first ear to reach the maximum other characteristics greatly affect this appropriate growth. height of 141.1 cm. Higher biostimulant same variable, such as ear insertion doses impaired the first ear insertion height and number of ears per area, The results corroborate studies on height; however, the insertion height which in turn have a high correlation different species of commercial interest with other characteristics, generating and sweet corn, which relate increases an indirect effect. Table 1. Estimates of Pearson’s linear correlation coefficients, between characteristics of sweet corn plants under different biostimulant doses (mL kg-1) applied to the seeds. Chapadão do Sul, UFMS, 2013. Characteristics HP HE SD POP NE MEW EI MEN HP 1 - - - - - - - HE 0.779** 1 - - - - - - SD 0.665** 0.628** 1 - - - - - POP 0.914** 0.795** 0.657** 1 - - - - NE 0.362* 0.722** 0.319ns 0.475** 1 - - - MEW 0.646** 0.781** 0.400** 0.647** 0.511** 1 - - EI 0.607** 0.477** 0.346ns 0.435* 0.267ns 0.300ns 1 - MEN 0.424* 0.664** 0.570** 0.475** 0.752** 0.395ns 0.325ns 1 HP= plant height; HE= first ear insertion height; SD= stem diameter; POP= final plant population; NE= number of ears per plot; MEW= mass of ears with husk; EI= ear index; MEN= mass of ears without husk; *,** and ns = significant at 1%, 5% probability and non-significant by t-test. 96 Horticultura Brasileira 38 (1) January - March, 2020

Development and production of sweet corn applied with biostimulant as seed treatment of the biometric characteristics observed until 28 mL kg-1, caused reduced ear These results may be related to the in the plant’s initial development with production, but the minimum production cell multiplication action promoted the physiological effect provided by the was reached without biostimulant by the phytohormones present in the biostimulant. For cucumber, tomato and application, reflecting the lower plant biostimulant during initial development lettuce crops, Vendruscolo et al. (2016) population obtained in this treatment, stage (Taiz et al., 2017) of sweet corn observed increases in the plant height, applying the dose of 15.7 mL kg-1. The plants, since determining the maximum leaf number, leaf size and shoot dry variation between the extremes in ear number of kernels is established in matter accumulation of the seedlings production was 18.6% (Figure 2A). stage V3 (Magalhães & Durães, 2006). when the seeds were maintained for 30 The results again refer to the adequacy In this sense, Dourado Neto et al. minutes in solution concentrations of 7.0 of the biostimulant doses employed so (2014) observed a similar situation in mL L-1, 4.92 mL L-1 and higher than 3.33 that the plant stand is adequate, since which application of Stimulate 10X mL L-1, respectively, before sowing. On the plant stand and number of ears are (1.0; 1.5; 2.0 mL kg-1) in corn seeds rice cultivation there are gains in shoot intrinsically linked characteristics. positively influenced the number of development by applying doses up to rows and number of kernels per ear 10 mL kg-1 to seeds (Rodrigues et al., For the variable mass of ears with when compared to the control treatment 2015), and for sweet corn increases in husk, the highest productivity per without biostimulant application. height, stem diameter, leaf area, stem hectare was reached using the dose dry matter, leaf dry matter and root dry of 16.4 mL kg-1, reaching 15,813 kg The cellular differentiation and matter were observed in applying doses ha-1, while higher doses reduced ear division during the plants vegetative up to 20 mL kg-1 on seeds (Cunha et yield. However, the lowest value was development is significantly affected al., 2016). obtained without applying biostimulant, by the flow of intracellular auxin. This 13,558 kg, representing a variation of flow allows the maintenance of adequate The highest population of sweet corn 16.6%, which is 2,255 kg per hectare. levels of this phytohormone which is plants was obtained at a dose of 12.4 mL kg-1, reaching 73,673 plants per hectare, Figure 1. Plant height (HP), first ear insertion height (EH) (A) and stem diameter (B) of an increase of 13.37% (8,688 plants) in sweet corn plants under different biostimulant doses (mL kg-1) applied to the seeds. Chapadão the final plant population comparing do Sul, UFMS, 2013. to the control treatment. Barbieri et al. (2005) verified that the sweet corn ear yield increased linearly with the increase of plant population. The authors also reported that sweet corn practically does not have productive plasticity, not compensating for the productivity when there is a smaller number of plants per area. In this way, the importance of correctly treating seeds using products with biostimulating action is perceived with the view to maintain the plant stand, and consequently good productivity. There was a decline in the plant population from the dose of 12.4 mL kg-1 to the lowest final plant population observed with a biostimulant dose of 28 mL kg-1 with 59,993 plants per hectare, inferring in 22.8% variation between these two extreme populations. In addition, when the dose of 28 mL kg-1 was applied to the sweet corn seeds a loss of 4,992 plants or 7.68% was observed on the final plant population. The highest amount of ears per hectare was reached with the dose of 15.7 mL kg-1, reaching 61,457 ears in a population of 73,061 plants ha-1. This reduction in ears is probably due to the high population density used. On the other hand, higher doses, Horticultura Brasileira 38 (1) January - March, 2020 97

SF Lima et al. responsible for numerous developmental water and nutrients. of 135 kg and 418 ears, when compared responses (Schaller et al., 2015). In to the doses of 15.7 and 16.4 mL kg-1, addition, the interaction between Considering the dose of 12.4 mL which promoted the highest number auxin and cytokinin governs virtually kg-1, where the largest plant population of ears per plant and mass of ears with all aspects of apical root meristem was reached, for the number of ears per straw. Despite the small difference, this development and, consequently, the hectare and mass of ears with straw, represents a value of about R$100 per growth of the root system (Schaller et the values obtained were 15,678 kg hectare. al., 2015), influencing the absorption of and 61,039 ears, respectively. These values represent a negative difference The highest yields of ears were reached using biostimulant doses close Figure 2. Final plant population (Pop) (A), number of ears (NE), mass of ears with husk to the best doses for stem development, (MEW), mass of ears without husk (MEN) (B) and ear index (C) of sweet corn under different characterizing a possible relationship biostimulant doses (mL kg-1) applied to the seeds. Chapadão do Sul, UFMS, 2013. between these variables. This occurs because a better stem structure may reflect increased kernel quality and yield through efficient use and translocation of carbohydrates to the kernels, since these events are negatively influenced by factors such as plant bedding (Pariz et al., 2011). Positive correlation was observed between most of the studied variables. Only among the variables index of ear with stem diameter, number of ears per hectare, ear mass with straw and ear mass without straw, between ear mass with straw and without straw and between number of ears per hectare and stem diameter no significance was observed for the correlations (Table 1). The mass of ears with straw, which is the main economic return variable for the producer, was positively correlated with plant growth characteristics, in addition to the final plant population and number of ears per hectare. This is a strong indication of the importance of seeking to improve other characteristics in the plant or crop in order to achieve higher yields. There is recommended that ears with husk mass is greater than 12 t ha-1 for corn destined for in natura consumption (Pereira Filho et al., 2003). In this context, all treatments reached higher productivity than this indication, with a general average of 15,061 kg ha-1. Even in the absence of Stimulate application, ears with husk productivity was above the recommendation of 13,558 kg ha-1. This higher value was expected because of the highest plant density used (74,000 plants ha-1), compared to the other study cited above (50,000 plants ha-1). For yield of ears without husks, biostimulant application of 15.4 mL kg-1 culminated in 11,444 kg ha-1, a value higher than that obtained by 98 Horticultura Brasileira 38 (1) January - March, 2020

Development and production of sweet corn applied with biostimulant as seed treatment Albuquerque et al. (2008) who obtained oxygen and, from these, the occurrence REFERENCES an average of 10,195 kg ha-1 of ears of oxidative degradation, senescence without straw with the same hybrid and cell death are observed (Pazmiño ALBUQUERQUE, CJB; PINHO, RGV; and a population of 50,000 plants ha-1. et al., 2012). This effect is widely used BORGES, ID; SOUZA FILHO, AX; The production behavior observed for in agricultural production systems for FIORINI, IVA. 2008. Desempenho de the ears without husk was similar to weed control (Grossman, 2010). In this híbridos experimentais e comerciais de milho that obtained for ears with husk, with way, the definition of optimum doses para produção de milho verde. Ciência e reduced productivity at doses above becomes essential in order to avoid Agrotecnologia 32: 768-775. 15.4 mL kg-1 and in the absence of productive and economic losses. biostimulant (Figure 2B). ÁVILA, MR; BRACCINI, AL; SCAPIM, CA; When used rationally, ALBRECHT, LP; TONIN, TA; STULP, M. The highest ear index was reached phytohormone-based biostimulants may 2008. Bioregulator application, agronomic with the biostimulant dose of 12.5 mL favor economic gains. It is observed that efficiency, and quality of soybean seeds. kg-1, reaching 0.89. The lowest ear index their use in different cultivated species Scientia Agricola 65: 567-691. was obtained at the highest applied dose results in increased productivity, as (28 mL kg-1), at which time the index carrot (Ávila et al., 2016), corn (Martins ÁVILA, J; LIMA, SF; VENDRUSCOLO, EP; reached 0.79, representing a variation et al., 2016) and soybean (Bertolin et al., ALVAREZ, RCF; CONTARDI, LM. 2016. of 12.7% (Figure 2C). Higher ear 2010). In this sense, sweet corn is also Adubação nitrogenada e uso de bioestimulante indices result in better utilization of the included, for which there was a small em cenoura. Magistra 28: 360-368. planted area, since they indicate that it share of the costs with the application of is possible to obtain higher yields with biostimulants and a significant increase BARBIERI, VHB; LUZ, JMQ; BRITO, CH; an equal or smaller number of plants. in the monetary return (Jesus et al., DUARTE, JM; GOMES, LS; SANTANA, 2016). DG. 2005. Produtividade e rendimento The results are once again linked to industrial de híbridos de milho doce em função the phytohormone action during the early The financial return that can be de espaçamento e populações de plantas. germination and plantlet establishment. obtained with the use of biostimulant Horticultura Brasileira 23: 826-830. The production characteristics (defined can be simulated considering the current during the V3 stage) are dependent product price at R$90 per liter and BERTOLIN, DC; SÁ, MED; ARF, O; FURLANI on the nutritional, physiological and the value received per kg of corn ears JUNIOR, E; COLOMBO, ADS; CARVALHO, environmental conditions in which the with husk at R$0.74. Under these FLBMD. 2010. Aumento da produtividade crop is found (Magalhães & Durães, conditions, at a dose of 16.4 mL kg-1 de soja com a aplicação de bioestimulantes. 2006). Thus, in addition to the direct which resulted in 15,813 kg ears, the Bragantia 69: 339-347. physiological effect on cell division and control produced 13,558 kg, resulting expansion maximized by the presence of in a favorable treatment difference of CASTRO, PRC; PEREIRA, MA. 2008. the hormone compounds present in the 2,255 kg. Expenditure on the use of the Bioativadores na agricultura. In: GAZZONI, product (Taiz et al., 2017), the effects product was R$30 per hectare and the DL (coord). Tiametoxam: uma revolução na on root development both in size and final profit obtained reached, therefore, agricultura brasileira. Petrópolis: Vozes. in accumulating matter (Cunha et al., R$1,638.70 per hectare with the use of p.115-122. 2016) contribute to soil exploitation by biostimulant. the plant, increases water and nutrient CUNHA, RC; OLIVEIRA, FDA; SOUZA, absorption capacity, and consequently Based on the results observed MDL; MEDEIROS, JF; LIMA, LA; improves vegetative and reproductive in the study, we concluded that the OLIVEIRA, MKT. 2016. Ação de development conditions. use of biostimulant results in gains bioestimulante no desenvolvimento inicial in the vegetative and reproductive do milho doce submetido ao estresse salino. The negative effects observed in development of sweet corn. The range of Irriga 1: 191-204. this work when applying high doses of biostimulant doses that allowed positive biostimulant may be reflexes from the results varied from 12.4 to 16.4 mL DAVIÈRE, JM; ACHARD, P. 2013. Gibberellin action of indolbutyric acid (IBA) and kg-1. Individually, the responses of the signaling in plants. Development 140: 1147- kinetin. When there are occurrences variables to the best dose was 12.4, 15.3, 1151. of levels above the optimal auxin and 13.7, 12.4, 15.7, 16.4, 15.4 and 12.5 mL cytokinin levels in plant tissues, even kg-1, respectively for plant height, first DOURADO NETO, D; DARIO, GJA; though these phytohormones are part ear insertion height, stem diameter, final BARBIERI, APP; MARTIN, TN. 2014. of the complex activity of cell division, population, number of ears per hectare, Ação de bioestimulante no desempenho there may be a marked effect on organ ear mass with and without straw and agronômico de milho e feijão. Bioscience growth inhibition such as the stem, ear index. Considering that the ear with Journal 30: 371-379. leaves and the ears (Taiz et al., 2017). straw is the product of sale and therefore the source of economic return to the FAO. 2018. Faostats: Crops. at: http://www.fao. Specifically, in the case of auxins producer, the dose of 16.4 mL kg is the org/faostat/en/#data/QC. Accessed February the deleterious effects are triggered best indication in this regard. 15, 2018. by the formation of reactive forms of FERREIRA, LA; OLIVEIRA, JA; PINHO, Horticultura Brasileira 38 (1) January - March, 2020 EVR; QUEIROZ, DL. 2007. Bioestimulante e fertilizante associados ao tratamento de sementes de milho. Revista Brasileira de Sementes 29: 80-89. GOMES, LS; BRANDÃO, AM; BRITO, CH; MORAES, DF; LOPES, MTG. 2010. Resistência ao acamamento de plantas e ao quebramento do colmo em milho tropical. Pesquisa Agropecuária Brasileira 45: 140- 145. GROSSMANN, K. 2010. Auxin herbicides: current status of mechanism and mode of action. Pest Management Science: formerly Pesticide Science 66: 113-120. HAMAYUN, M; KHAN, SA; KHAN, AL; SHIN, JH; AHMAD, B; SHIN, DH; LEE, IJ. 2010. Exogenous gibberellic acid reprograms soybean to higher growth and salt stress 99