FFA Research Digest 2017

THE UNIVERSITY OF THE WEST INDIES ST AUGUSTINE CAMPUS TRINIDAD & TOBAGO, WEST INDIES FACULTY of FOOD and AGRICULTURE RESEARCH DIGESTSoil Pro le St Augustine Series

Research Digest EditorsWayne Ganpat and Sarojini Ragbir The University of the West IndiesSt. Augustine, Trinidad and Tobago November 30th, 2017

Publisher: The Communications and Publications UnitPrinters: Faculty of Food and AgricultureCover design: The University of the West Indies St. Augustine Campus, Trinidad and Tobago Multimedia Production Centre, UWI, St. Augustine Trinidad and Tobago Terry Sampson ACKNOWLEDGEMENTSSpecial thanks to Ms Sarojini Ragbir, CommunicationsCoordinator for editing, typesetting and other tasks associatedwith this production.Thanks also go to Dr Gaius Eudoxie, Deputy Dean Outreachand Internationalization, for all his support in the production ofthis Digest.

1TABLE OF CONTENTSFOREWORD 2 SECTIONS:1. Food Production 32. Food Security 493. Nutrition, Food Safety and Consumer Science 604. Climate Change 825. Extension and Rural Development 92 1056. Geography and the Environment 7. Faculty Collaborative Research Projects' Summaries 115

2 FOREWORD The compilation of abstracts and summaries in this document standsas testimony to the vibrant work of the Faculty of Food and Agriculture insupporting food and nutrition security objectives in the region. An overviewof the research that has been conducted or that is on-going, shows therelevance of work being pursued; geared towards addressing some of themost important concerns in the Caribbean. Readers will note that while full-time academic staff are leading research initiatives, a fair amount of the workpresented represents valuable work done or being pursued by students; bothgraduate and undergraduate in some instances. This augurs very well forcontinued quality work out of the FFA in future years! The abstracts in this publication are categorized along major thematiclines. Under Food Production, abstracts refer to the exciting work done onprotective structures, controlled environment systems, breadfruit production,root crops, and soil and water management. Some of the extensive work inneo-tropical species as well as small ruminants are also abstracted. FoodSafety has become a major concern for the region and is being addressed,in the areas of processing, street foods and other post production practices.Work being done locally and regionally to address climate change impactsand regional food security are timely and encouraging; the FFA is contributingsignificantly in this important area. The FFA is actively addressing regionalconcerns in the area of nutrition; obesity, diabetes, hypertension, eatinghabits, and consumers’ behaviours are all being investigated and someare reported. Work being done to address environment concerns and ingeography validates that the Faculty shares national and regional prioritisationof ensuring environmental sustainability. The need for new extension andcommunications approaches to hasten agricultural development is alsobeing investigated regionally and some decisive findings are presented. Finally, abstracts presented are comprised of both published works,works completed but not yet published, as well as on-going research conductedwithin the last five years. Some minor editing of abstracts has been done to\"de-jargonize\" the work to facilitate wider understanding; particularly by ourstakeholders outside of the academic arena. I congratulate all members of the Faculty of Food and Agriculture fortheir strong commitment to quality research and their demonstrated desire toshare their work with the wider community; both in The UWI and Region. The FFA stands tall with this Research Digest!Wayne Ganpat, PhDDean, Faculty of Food and Agriculture

3FOOD PRODUCTION

4 Prediction of Clay and Sand Content Using Wilting Point and Hygroscopic Water Content Kegan Farrick1 and Mark Wuddivira2 1Department of Geography and 2Department of Food Production, UWI Soil texture is an important factor governing a range of physical,biological and chemical processes in soil. The clay content is particularlyimportant in controlling soil water retention, hydraulic properties, water flowand transport. Modern soil texture analysis techniques such x-ray attenuation,laser diffraction and particle counting have become more common. However,these methods are very laborious and the cost of the equipment is substantial.The recent development of chilled-mirror dewpoint potentiometers allowfor the rapid measurement of the permanent wilting point of soil. As thewilting point is strongly dictated by soil texture, the applicability of adewpoint potentiometer in determining the clay and sand content was tested. A comparison of the predicted values from the wilting point with thatof the hygroscopic water content whose determinations are rapid, cost effectiveand less laborious than other methods was done. Using nine surface and ninesubsurface soil samples, we determined the moisture content at wilting point.The r2 values for the regression equations of soil moisture at wiltingpoint as a function of clay and sand content were 0.92 and 0.86respectively. The root mean square error (RMSE) for the modelledclay and sand content using the wilting point was 4.9% and 6.6%respectively while the RMSE for the modelled clay and sand contentusing the hygroscopic water content was 5.9% and 8.8% respectively. The results suggest that the wilting point technique has a greaterpotential to estimate soil texture than hygroscopic water content. Despite theeffectiveness of the wilting point in determining the soil texture, the low costand low technical complexity using the hygroscopic water content makesit more attractive for use in developing countries. Ongoing work includesthe addition of more soil samples to capture a wider range of soil textures.

5 Evaluation of Local Epigeic Earthworms in the Vermicomposting of different types of Organic Substrates with Varying Qualities Micah Martin, Gaius Eudoxie and Gregory Gouveia Department of Food Production, UWI Vermicomposting is a process, which relies on the decomposingactivity of earthworms in association with beneficial microorganisms forrapid break down and stabilization of organic waste. The most commonly used species for vermicomposting are Eudriluseugeniae (African night crawler), Perionyx excavatus (India Blue) and Eisenafetida (California red). The adoption of vermi-technology locally is hinderedby the availability of these species and lack of research on the suitabilityof indigenous species. Regulations governing the importation of exoticspecies are also very stringent. This research therefore seeks to fill this gap byevaluating local species for their suitability in vermicomposting. Objectiveswere (i) Identify and classify local earthworms based on their taxonomy (ii)Understand how feed quality and feed rate influence reproductive behavioramongst species (iii) Evaluate the agronomic quality and potential use ofvermicompost. A purposive sampling method was adopted for collecting speciesin typical and non-typical areas around Trinidad and Tobago. Samplesof these species were then preserved in 80 % alcohol for taxonomicidentification and the rest were cultured in pen manure and observedfor their suitability. Earthworms that were regarded as suitable werefurther evaluated under experimental conditions. Earthworm responseto variations in C/N and feed rate were evaluated. Parameters measuredincluded earthworm adult and juvenile biomass and vermicast quality.The influence of bio-available forms of carbon amongst similar substrateswas further evaluated to determine variations in reproductive behaviorfrom the earlier experiment. Vermicompost derived was evaluated using aseedling bioassay for phytoxicity and growth response. Results suggest thatindigenous species are more acclimatized to local conditions, thereforethe need for importing exotic composting species is reduced. Moreover,the indigenous species would be more adopted to local waste substrates. The findings will guide the use of earthworms for processing differ-ent types of organic wastes and initiate the development of a new industry inearthworm farming, organic waste processing and other linkage industries.

6 Economic Feasibility of Plant Factory Grown Lettuce Productivity in Response to Supplemental Lights in Trinidad and Tobago Nkosi Felix1, Jessica Churaman1, Wendy-Ann Isaac1, Mattias Boman2, Renique Murray1 1Department of Food Production, 2Department of Agricultural Economics and Extension, UWI Trinidad and Tobago with a population of 1.3 million, imported$4 billion in food in 2014. The exchange rate compounds this expendituresince in 1995, 5.99TTD was equivalent to one (1) USD while at the end of2014 the exchange rate increased to 6.37TTD for one (1) USD. Thereforean additional 6% (TTD$76 million) was required to purchase same volumeof food in 2014, but with a 400% increase in imports in 2014 an additionalTTD$300 million was lost. It was shown that USD$1.6 million in lettuce(1,585,000 kgs/ 483,000) was imported in 2015, with 375,000 heads (114,000kgs) domestically produced. Although, Trinidad and Tobago has a tropicalclimate which allows for the production of this commodity, climatic factorsalong with environmental factors have negatively impacted its productiveefficiency. Therefore to reduce or eliminate the negative impacts of changingclimate on the production capacity, the feasibility of growing lettuce undercontrolled environments , such as a plant factory, was investigated. Twovarieties of lettuce were grown under High-Output florescent (T5), LightEmitting Diodes (LED), and Light Emitting Plasma (LEP) lights andcompared to lettuce grown in greenhouse and open field production systems.Growth models were established using regression models to identify thesignificance of light, temperature, carbon dioxide, and relative humidity onthe parameters of lettuce growth. In addition, given the increased capitaloutlay and energy requirements of plant factories, cost was also modeledwith agronomic factors to identify which system was the most efficient inconverting cost to yield. It was observed that plant growth was influencedby the modification of climatic factors, which had a positive impact on thecost to return ratio of a plant factory. Results of this study are expcted toencourage the investment into plant factories and therefore reduce Trinidadand Tobago’s dependency on imports and vulnerability to international shocks.

7 Ammonia Loss from Acid Soils as a Consequence of Over-Liming Gregory Gouveia, Shedonna Richardson and De Shorn Bramble Department of Food Production, UWI A factorial experiment with 7 soil-lime treatments x 3 N treatmentsreplicated 3 times were incubated in mason jars (63 experimental units) fora period of 28 days, to determine NH3 emitted based on a slightly modifieddesign of that described by Khan, Mulvaney and Mulvaney (1997). Ofthe seven soil-lime treatments, 6 included 3 acid soils of diverse textures(Arena, River Estate “RE” and Talparo “Tal”) with (C1) and without (C0)laboratory-grade CaCO3 applied at 5% w/w. The 7th treatment was a highactivity calcareous clay (Princes Town “PT”). The N treatments includeda no-N (control), urea and ammonium chloride (AC), each added at a rateof 100 kg N/ha. All soil-lime treatments were brought to 100 % FC priorto addition of the N treatments and rewetted only once after 18 days andthe NH3 emitted was monitored after 1, 3, 5, 8, 12, 18, 19, 22 and 28 daysby inserting a PVC cap attached to the jar-cover, with 5ml boric acidindicator solution for 24 hrs. On removal of the acid-traps the amount ofNH3 emitted was estimated after back-titration with standardized H2SO4.There was a significant (p < 0.05) interaction between the soil-lime treatmentsand the N treatments on NH3 emission rates. N controls were negligibleacross all soil-lime treatments, but the rates were highest when urea wasapplied to the arena soil. While with the limed Arena soil (Arena-C1)emissions on day 1 were negligible, by day 3 the highest rate of 10 kg N/ha/day was recorded and declined to < 3 kg N ha-1 day-1 by day 5 and to< 0.5 kg N ha-1 day-1 by day 12. Correspondingly, the limed Arena soiltreated with ammonium chloride (AC) did not show a delayed emissionas seen with urea but had its highest emissions (2.8 kg N ha-1 day-1) onday 1 which declined to less than 0.5 kg N ha-1 day-1 around day 18. Itmeant that the emissions lingered for a slightly longer time in the limedarena soil treated with ammonium chloride compared to urea. While therewas also delayed emission of NH3 from the un-limed Arena soil treatedwith urea that peaked at day 3 at just over 4 kg N ha-1 day-1 and declinedsignificantly to being negligible by day 12, emissions from the same un-limed soil treated with AC were negligible throughout the incubation period.Cumulative emissions (up to day 28) were the highest for the limed-arenasoil fertilized with urea at 31.9 % which was significantly (p < 0.05) higherthan all other treatments, and followed by un-limed arena also with urea at17.7 %, then limed arena with ammonium chloride at 16.9%. Cumulativeemissions from all other soil-lime-N treatment combinations were < 5 %. Themain effects of both the soil-lime treatments and the N treatments were alsosignificant (p < 0.05). The average cumulative emission from the limed arenasoil (24.4 %) was almost three times greater than the next highest, which wasthe un-limed arena soil and all other soil-lime treatments were actually < 4%.

8 The Arena soil had the highest emissions of NH3 (31.9 % of addedurea-N) while the emissions from the Talparo clay soil was negligible, theeffects of liming on emissions were most significant for the Arena soil. TheNH3 emissions from soils treated with ammonium chloride were only lowerthan that from urea for the Arena soil (with and without lime), while for allother soils, including the calcareous Princes Town clay soil, there was nosignificant (p < 0.05) difference in the emissions between the two N fertil-izers. The emissions from these soils ranged from 0 – 3.9 % of added-N.

9Yield, Quality and Nutritional Status of MMEX Cassava Grown onTropical Acid Soils in Response to Conjunctive use of Nitrogen and Lime Gabrielle de Souza, Gaius Eudoxie and Lynda Wickham Department of Food Production, UWI Food security has become a major issue and alternatives to staple foodssuch as wheat, rice and potato is vital for sustainability. Root crops have beenidentified as a suitable alternative; specifically cassava. Cassava (Manihotesculenta Crantz) is the third largest source of carbohydrates in the tropics(FAO, 2008). The tubers are a nutritious source of starch and they containsignificant amounts of calcium, phosphorus and vitamin C (Pilla, 2011).Cassava is traditionally grown on poor quality soils, resulting in lower thanaverage yields. Low yields (10,000-15,000 lbs/acre) are associated withgenetic and ecological factors, in addition to inappropriate soil fertility andcrop nutrient management. Cassava in particular is tolerant of soil acidityand high levels of aluminium (Gunatilaka, 1977; CIAT, 1979; Islam et al.,1980), but some varietal differences in acid soil tolerance have also beenobserved (CIAT, 1982; 1985a; Howeler, 1991a). In very acid (pH<4.5) andhigh aluminium (>80% Al saturation) soils, lime application may increasecassava yields, mainly by supplying calcium and magnesium as nutrients.Thousands of fertilizer experiments conducted by FAO worldwide indicatethat cassava is as responsive to fertilizer applications as other crops, withyield increases of 49% (West Africa) to 110% (Latin America) vs. increases of43% (yams and rice in West Africa) to 102% (rice in Latin America) for othercrops. In West Africa (Ghana) cassava responded mainly to potassium; inLatin America (Brazil) to phosphorus; and in Asia (Indonesia and Thailand) tonitrogen (Richards, 1979; Hagens and Sittibusaya, 1990).The main objectiveof this study was to determine the interactive effects of nitrogen rate andlime on soil fertility, yield, crop nutrition and post-harvest quality of cassava.Experiments will be conducted to determine the optimum nitrogen rate forMMex cassava cultivation. In addition, compounding effects of soil propertiesand liming will also be ascertained. Analyses would be done on the nutritionalstatus of the soil and leaves, with particular attention on micronutrientavailability in the aforementioned. Tubers will be analysed on yield, dry mattercontent, cooking time and occurrence of vascular streaking. It is expected thatoptimal rates of nitrogen fertilization for cassava will result in improved yieldsand quality of cassava tubers. Similarly, liming should also improve cassavayields as well as micronutrient availability and uptake in acidic soils inTrinidad.

10 Predicting the Distribution of Naturally Occurring Phosphatic Soils across a Countywide Landscape, Florida, USA Ravindra Ramnarine1,2, Willie G. Harris2 and Sabine Grunwald2 1Department of Food Production, UWI 2Soil and Water Science Department, University of Florida, Gainesville, Florida, USA A GIS approach was used to test a conceptual soil-landscape modelwhich integrates topographic, geologic and soil information for predictingthe distribution of phosphatic soils. The hypothesis was that phosphaticsoils occur on erosional landscapes where phosphatic geologic materialsare exposed at or near land surface. Areas of high (scarp), medium (plain),and low (plateau) likelihood of such exposure were delineated based ontopographic and geologic information. An initial predictive phosphatic soilsmap was created and validated by field sampling. Samples were taken at twodepths: upper (0–25 cm) and lower (100–125 cm); and the total phosphorus(TP) was determined. Mean TP concentration for the lower depth was 6195mg kg−1 for the scarp, 2485 mg kg−1 for the plain, and 193 mg kg−1 forthe plateau. The initial map was revised to show that the probability offinding a phosphatic soil was highest for the scarp region (73%), mediumfor the plain region (33%), and lowest for the plateau region (7%).Source: Ramnarine, Ravindra, Willie G. Harris, and Sabine Grunwald. 2015.\"Predicting the Distribution of Naturally Occurring Phosphatic Soils across aCountywide Landscape, Florida, USA.\" Communications in Soil Science and PlantAnalysis 46:1391-1410

11 Conventional and No-Tillage Effects on the Distribution of Crop Residues and Light Fraction Organic Matter R. Ramnarine1,2, R. P. Voroney2, C. Wagner-Riddle2, K. E. Dunfield2 1Department of Food Production, UWI 2School of Environmental Sciences, University of Guelph, Canada Tillage management on agricultural soils is important because ofits effect on soil organic matter (SOM) dynamics. The decomposition offresh crop residues to stabilized organic matter by soil microbes results in acontinuum of intermediary SOM fractions or pools. The light fraction organicmatter (LFOM) represents one of the SOM pools formed in the early stagesof decomposition and is distinguished as a potential labile SOM pool which issensitive to changes in management practices. The objective of this study wasto measure the quantity, distribution, and d13C signature of the LFOM pool infarmland soils managed under a conventional tillage (CT) and no-tillage (NT)system. The study used the d13C natural abundance technique which involveda crop rotation of C3 and C4 species on a calcareous Typic Hapludalf soil.The LFOM was obtained using density fractionation, while the organic C,N, and d13C of whole soil and light fraction were measured using hightemperature combustion coupled with isotope ratio mass spectrometry.Our findings showed that there was a significant increase in the lightfraction C and N pools in the NT soils compared with the CT soils after6 yr of NT. There was a higher proportion of corn-derived C in the lightfraction in the 0- to 10- and 10- to 20-cm depth of NT soils. The differencesin the isotopic signature of the whole soil and SOM fractions also show apreservation of newly derived C in the NT soils compared with the CT soils.Source: Ramnarine, R., R. P. Voroney, C. Wagner-Riddle, and K. E. Dunfield. 2015.\"Conventional and no-tillage effects on the distribution of crop residues and lightfraction organic matter.\" Soil Science Society of America Journal 79: 74-80

12 Rotary Drum Compost and Compost Tea as Substrates, Amendments, and Biocontrol Agents for Damping-off (Pythium ultimum) Management in Tomato (Solanum lycopersicum) Chaney St. Martin, R.A.I. Brathwaite and G. Eudoxie Department of Food Production, UWI The use of costly imported peat (Sphagnum spp.)-based substrates,which are conducive to damping-off, limits the profitability of commercialvegetable enterprises in the Caribbean. The primary goal of this dissertationresearch was to assess high-rate rotary drum technology as a means ofproducing mature banana leaves (Musa acuminata Colla) and lawn clippings[Axonopus compressus (Swartz) Beauv.] composts of consistent quality, foruse as soil-less growth substrates, which are suppressive to damping-off(Pythium ultimum) in tomato (Solanum lycopersicum). The use of compost teaas a nutrient amendment and biocontrol agent against damping-off of tomatocultivated in compost-amended peat-based substrate, which is inoculatedwith the endomycorrhizal fungi Glomus intraradices, were also investigated.Stable composts, which were produced within 19 d using rotary barrelcomposters, had significantly higher P. ultimum suppression efficacythan the commercial fungicide UltraFlourish® (Nufarm AmericasInc., Illinois, USA), consistent quality across production batches, andwere suitable for use as substrate components at an inclusion rate of20% (v/v) with peat-based substrate inoculated with G. intraradices.Across compost types, bacterial population was positively related togrowth inhibition of P. ultimum whereas total microbial population had apositive relationship with growth inhibition in lawn clippings compost.Compost teas stimulated in vitro seed germination of tomato andsignificantly higher P. ultimum growth inhibition levels were achievedwith lawn clippings compost teas (86%) compared to banana leavescompost teas (36%). Yeast populations of aerated compost teas werepositively related to growth inhibition whereas bacterial populations had apositive relationship with growth inhibition for non-aerated compost teas.Damping-off was suppressed 100% when aerated compost tea made fromlawn clippings compost was applied to peat-based substrate inoculatedwith G. intraradices. G. intraradices did not colonise tomato andunfiltered compost tea + fertiliser applied to peat-based substrate resulted insignificantly higher tomato seedling growth than the fertiliser only treatment. Research findings show that the compost teas produced, may be ofgreater practical relevance to farmers as amendments and biocontrol agentsagainst damping-off than compost.

13 Molecular Microbial Ecology and Nitrifying Communities of Tropical Composts and Soils Vidya De Gannes1, Gaius Eudoxie1 and William J. Hickey2 1Department of Food Production, UWI 2O.N. Allen Laboratory for Soil Microbiology, Department of Soil Science, University of Wisconsin-Madison, Madison, WI, USA Microorganisms such as prokaryotes and fungi play key roles indecomposition processes while ammonia- oxidizing bacteria (AOB) wasbelieved to be the only group of microorganism that mediated nitrification,a key process in both composting and soils. While some previous studieshave reported on some microorganisms in composts, many questionsremained regarding the dynamics of prokaryotic and fungal communitiesin the composting process, such as, whether unifying patterns in one orboth groups of microbes can be identified as composting progress acrosscompost types, about compost safety and how microbial communitycomposition vary throughout the composting process across composttypes. The recent discovery of ammonia-oxidizing archaea (AOA) haschanged the century-old paradigm that nitrification is mediated solelyby AOB and has driven re-examination of nitrifying communities insoils and composts. Thus, the main objectives of this research were:to investigate how AOA and AOB communities vary among composttypes during the composting process, to determine prokaryotic and fungalsuccessions in composts and to understand potential role of AOA andAOB in nitrification in tropical soils. Agricultural wastes, rice straw, sugarcane and coffee hulls were combined with either sheep- or cow-manurefor the composting process and microbial communities were determinedfrom samples at initial, mesophilic and mature phases. Next-generationsequencing was applied to analyze prokaryotic and fungal patterns. For theprokaryotes, in all composts, diversity expanded as composting progressedand mature-phase compost was a preferred niche for prokaryotes: Archaea,Planctomycetes, Chloroflexi and Deltaproteobacteria. The AOA in compostwere more abundant than AOB in composts and nitrification patterns andlevels differed in the composts which, for the mature material, could havesignificant effects on its performance as a plant growth medium. In soils(9) from Trinidad, nitrification potential and AOB and AOA quantities weredetermined. Results revealed that AOA and AOB communities were affectedby different sets of soil factors.Source: De Gannes, Vidya. \"Molecular microbial ecology and nitrifyingcommunities of tropical composts and soils.\" PhD diss., 2015

14 Effects of Composting Systems on the Quality of Neem Compost and Non-aerated Compost Teas, and their Combinatory Effects on CropNutrition and Phytophthora capsici Suppression in Moruga Red Pepper (Capsicum chinense) Bryan Smith, Gaius Eudoxie and Ravindra Ramnarine Department of Food Production, UWI Hot pepper (Capsicum chinense) is an important export crop suitedfor the diversification of traditional crop selections. However, several factorsaffect its competitiveness on the export market despite the crop having anecological advantage in the Caribbean. Two of the main challenges havebeen the prevalence of Phytophthora capsici, a soil-borne pathogen, infields causing immense losses to farmers, as well as the decline in cropnutrition and yield as a result of the pathogen. To date, control strategiesin developing Caribbean territories have been limited and geared towardschemical control which is not sustainable and poses several environmentalrisks. These challenges have prompted investigations into alternativeand sustainable strategies that can improve crop health and nutrition. The production and use of compost and compost teas have beenrecognized as a sustainable soil management strategy of reasonableoperational cost that can reduce reliance on chemical inputs in cropproduction. However, composting system and feedstock content mayinfluence the efficacy of the resultant product. Such inconsistenciesin quality and effectiveness of compost have prompted investigationsinto feedstock blends subjected to differing composting systems. Neem has been documented as a plant with vast potential inthe agricultural sphere, particularly because of its unique antimicrobial,insecticidal and nitrification inhibitory properties that are attributed to aclass of bioactive compounds called isoprenoids (Azadirachtin related-limonoids). Yet, the utilization of Neem leaves as a substrate in compostinghas been investigated on a limited scale with efforts being placed on itsability to be consumed without debilitating effects on earthworms duringvermicomposting. Neem fruits have also been emphasised in the literaturebecause of their high concentration in azadirachtin, an insect growth regulator.However, Neem fruits are seasonal and not abundantly obtainable in highvolumes through pruning practices in comparison to the leaves. Furthermore,to date, there is no information regarding the transformation and prevalenceof Neem bioactive compounds throughout and after the decompositionprocess known as composting. However, if bioactive compounds dopersist in the compost, the combinatory action of the microbial consortia

15along with neem bioactive compounds may improve the suppressive andnutritive value of the compost. Consequently, this research will evaluate ifthe addition of Neem leaves at varying rates to two different compostingsystems (vermicomposting and rotary drum thermophilic composting) willincrease the inherent properties of the end product as a disease suppressantfor P. capsici and nutrient amendment in Moruga Red Pepper production.Additionally, the outcome of this research is expected to:• Provide a cost-effective and sustainable alternative to syntheticfertilizers and fungicides that can be easily adopted by small rural farmers byincreasing the suppressive and nutritive capabilities of the compost.• Aid in creating more public knowledge surrounding Azadirachtaindica (Neem) role in crop protection and as an organic soil amendmentwithin the Caribbean region.• Provide sufficient data on Neem compost and compost tea as adisease suppressant and nutrient amendment to convince farmers of the use,application, timing, and benefits.• Allow for an economic analysis (competitive ability) of the usageof Neem based compost and compost teas on P. capsici suppression in hotpeppers in comparison to commercial fungicides.• Increase the potential to create novel bio-formulations from thebioactive compounds and neem-compost specific microorganisms which canbe used to increase fertility and disease suppression in the field.

16 Alternative Greenhouse Technology: The use of Bamboo forGreenhouse Construction in Manzanilla Government Secondary School Lincoln McDonalda, Kenia-Rosa Campoa, Rakesh Bhukalb, Wendy-Ann Isaaca, and Wayne Ganpatc aDepartment of Food Production, bFaculty of Medical Sciences, cDepartment of Agricultural Economics and Extension, UWI High-tech agriculture, as it is practised in the technologicallyadvanced countries, is exorbitantly costly. Need was urgently felt forstandardising a cheaper technique, more suited for the conditions inMayaro/Manzanilla. A study was undertaken by The University of theWest Indies and Perenco to identify the role played by each elementin the high-tech agricultural technology. This study showed that thegreenhouses in Trinidad and Tobago were based on the European conceptof growing crops in a hot-house during winter, with the difference thatinstead of heating, they were cooled naturally and artificially in Trinidadand Tobago. So in the Caribbean the technology was adapted to serve thepurpose of protecting the crop from hot, dry winds and providing additionalcarbon dioxide to the plants for increasing their rate of photosynthesis.A greenhouse structure was constructed out of bamboo as analternative to steel. It showed weight for weight, the load bearingstrength of bamboo to be six times that of steel, while, its cost isjust 20 percent that of steel with labour for harvesting included.

17 Biocontrol Potential of Bacillus amyloliquefaciens against Postharvest Anthracnose of Hot Pepper Rayanna Boodram and Duraisamy Saravanakumar Department of Food Production, UWI The Scotch Bonnet Hot pepper (Capsicum chinense) is one of themore popular varieties cultivated in Trinidad. It’s vibrant color, aroma andtaste makes it an excellent choice for hot pepper by-products and it is highlydemanded for export. The Anthracnose disease caused by Colletotrichumgloeosporioides is one that devastates the crop because all stages of thecrop’s lifecycle is susceptible. The study aims at exploring antagonisticeffects of Bacillus strains against Colletotrichum, the pathogen that causesthe pre and postharvest anthracnose disease in hot pepper plants and fruits.The pathogen was isolated from an infected hot pepper fruit and grownin laboratory conditions. Bacillus strains isolated in the Plant PathologyLaboratory of the Department of Food Production under UWI RDIFund AIMS project were tested against the anthracnose pathogen usingdual culture technique. Among various Bacillus species tested, Bacillusamyloliquefaciens strains showed high inhibition to the anthracnosepathogen under in-vitro conditions. The biocontrol potential of B.amyloliquefaciens strains was further studied against anthracnose infectionin hot pepper fruits under in vivo conditions. Results indicated reducedinfection in hot pepper fruits by application of B.amyloliquefaciens strainsCHAG1D and PRIN6 compared to untreated control. Further experimentsto test the potential of these strains under field conditions are in progress.

18 Antagonistic effect of Rhizobacteria against Black Mould Disease of Okra Riad Rampat and Duraisamy Saravanakumar Department of Food Production, UWI Okra (Hibiscus esculentus) is one of the more important vegetablecrops cultivated in Trinidad. The cultivation of this crop is affected byvarious pests and diseases. Of several diseases, the occurrence of foliardisease appears to be a major problem in commercial cultivation of Okra.Leaf samples showing black coloured spots in okra plants were widespreadin farmers’ field in the location of Orange Grove area, Trinidad. The infectedleaf samples were collected from the farmers’ field for further diagnosis. Thesymptoms were black to brown in colour that predominantly appeared onlower side of the leaves. The infected leaf samples were used for isolationof the pure culture. The fungus isolated from infected leaf samples showedelongated, cylindrical and Cercospora conidia produced typically fromclustered conidiophores with 5 to 7 septations. A survey was carried out onthe occurrence of disease in various okra grown areas. The percent diseaseindex ranged between 18-72% at different locations. The maximum diseaseindex (72%) was recorded at Orange Grove, followed by Aranguez (42%) andRio Claro (18%). Severe leaf spot disease was conventionally sprayed witha commercial fungicide to control spores, but this had no significant effect. The widespread occurrence of this Cercospora leaf spot disease hasfurther triggered research interest to devise a suitable management strategyfor the successful cultivation of okra and to minimize the use of chemicalcontrol. Rhizobacterial strains were isolated from the soil were used to studythe plant growth promotion and antagonistic activity against Cercospora ofOkra. Results showed that rhizobacterial strains ROX 2i, ROX 2B, ROX2J, SCAB 1E, SCAB2A significantly increased the root and shoot growthof okra seedlings in continuous experiments carried out under in-vivoconditions. The biocontrol potential of these strains in the control of okraleaf spot disease is the subject of ongoing research. Results could change thepesticide-driven approach to more biological approaches to crop protection.

19 Can Indigenous Rhizobacteria Defend Tomato Against Bacterial Wilt Disease? Augustus Thomas and Duraisamy Saravanakumar Department of Food Production, UWI The successful production of tomato is hindered by occurrence ofpest and diseases in the Region. Of several pests and diseases, wilt diseasecaused by a soil borne bacterium, Ralstonia solanacearum is considereda serious constraint in the production of tomato. It has been reported inmany of the Caribbean islands including Dominica, Trinidad, Belize,Cuba, Martinique, Guadeloupe, St. Lucia, Puerto Rico, St Vincent and theGrenadines, Haiti, Grenada, Jamaica, Costa Rica and Dominican Republic.Use of pesticides and already existing practices like soil fumigation,soil solarization have limited effect on the control of bacterial wilt. Several researchers outside the Caribbean Region have exploredthe successful use of indigenous beneficial rhizobacteria in the controlof bacterial wilt disease. Thus, it is hypothesized in the current researchthat exploration of native rhizobacteria could offer a solution to thecontrol of bacterial wilt disease in tomato. This research is conductedto isolate and evaluate the antagonistic potential of native rhizobacteriaagainst bacterial wilt disease in tomato under greenhouse conditions. The bacterial wilt pathogen was isolated from the wilt affectedtomato plants. It was further confirmed on tetrazolium chloride agar. Sixty-two rhizobacteria strains were isolated and tested for their efficacy against thewilt pathogen using filter paper disc and streak method in the laboratory. Out of 62 isolates, nine rhizobacteria isolates inhibited the growthof the bacterial wilt pathogen. However, Bacillus subtilis strain OG2demonstrated the greater level of suppression of the bacterial pathogen onthe Filter Paper Disc Method with the complete obstruction of the pathogenin the lab. Nine rhizobacteria isolates were evaluated for their efficacy todefend tomato plants against wilt disease under greenhouse conditions. Theexperiment was conducted by raising tomato plants treated with rhizobacterialstrains and artificial inoculation with bacterial pathogen. It was found thatthe greater level of protection was offered by Bacillus subtilis strain OG2 totomato plants against bacterial wilt disease under greenhouse conditions. Theassessment of growth promoting potential of rhizobacterial strains exhibitedthe increased growth in tomato plants treated with Bacillus subtilis strain OG2and Azotobacter strain SAG19. The preliminary results in the greenhousestudy have demonstrated some potential of the rhizobacteria, Bacillus subtilisOG2 against bacterial wilt in tomato plants.

20Assessing the Biological Control of Rhizobacteria against Choanephora and Cercospora on Cowpea Akielia Mc Pherson and Duraisamy Saravanakumar Department of Food Production, UWI The Commercial production of Cowpea has affected within theTrinidad and Tobago due to wide range diseases. Two of attributing diseasesare Choanephora pod rot and Cercospora leaf spot. The increased chemicalapplication to control these diseases has left consumers concern with pesticideresidue on produce purchased. These diseases were predominately severe infields cultivated in Orange Grove, Trinidad. Infected plant samples of leavesand pods were collected from farmers’fields. Samples isolated to produce purecultures of both disease for further investigation. Of both fungi isolated, thereconidial structured differed in appearance. Chaonephora conidia appearedas cluster of fine, reddish, oval conidiophores while, Cersocpora condiaappeared to be elongated cylindrical conidiophores with 5 to 7 separation. Forfurther investigation biological control, was seek, providing an alternative tochemical measures. Rhizobacteria strains were explored as potential biologicalcontrol. Rhizobacteria strains were collected from villages of Roxborough(ROX) and Scarborough (SCAB) located in Tobago. Initial test were done toprove effectiveness of Rhizobacteria strains in the form of dual plate assayand growth promotion assay, to test the efficacies of the strains. Results ofthe dual plate assay of Chaonephora and Cercospora asserted ROX 4A andROX 2E had highest inhibition average of 32.94% and 91.76% respectively.However, pertaining to growth promotion assay ROX2B resulted in mean rootlength value of 25.80. SCAB 2P had highest mean shoot length of 14.70 withcombined root and shoot length. ROX 2B surpassed all the other treatmentsin the growth promotion test, resulting in total plant length of 39.6cm.Greenhouse trails to assert the potential biological control of Rhizobacteriastrains on Choanephora and Cercospora diseases in Cowpea are ongoing.

21Evaluating the Potential of Rhizobacteria for the Control of Cercospora Leafspot in Lettuce Augustus Thomas and Duraisamy Saravanakumar Department of Food Production, UWI Lettuce is a widely produced vegetable in the Caribbean and itgenerates income for farmers in short term vegetable crop production. Thoughthe crop duration is short, the fungal disease caused by Cercospora spp. isconsidered to be a serious constraint in lettuce production. The application offungicides has been the prevailing disease control strategy for managementof Cercospora leaf spot in the region. The continuous and indiscriminateapplication of fungicides especially in leafy vegetables like lettuce havebeen the major concern as it leads to the persistence of pesticide residues anddevelopment of resistance in the pathogen. Considering this scenario, it isnecessary to develop the alternate strategies which could reduce the applicationof pesticides and ensure the production of quality food. In this regard, thedevelopment of biological control strategies has gained attention in this study.The current study focused on (i) isolation and use of host extract on growthand sporulation of Cercospora infecting lettuce and (ii) identificationand characterization of rhizobacteria that are able to antagonizethe pathogen Cercospora which causes leafspot disease in lettuce.Being the hembiotrophic fungus, it was reported as difficult to isolate andsporulate the culture. The study standardized the innovative isolationtechnique and developed the suitable medium for sporulation. Nearly 200rhizobacterial strains were isolated from different agricultural ecosystems ofTrinidad. All the rhizobacterial strains have been tested for their antagonisticactivity against Cercospora isolated from the infected lettuce samples. Of200 rhizobacteria strains, 64 strains inhibited the fungal growth in dualculture technique. Among 64, ten rhizobacterial strains proved to be moreeffective and accounted for more than 50% inhibition of the fungal pathogenin vitro. The molecular analysis of these strains revealed that they areBacillus amyloliquefaciens. The strains were identified as strong producersof lipopeptides such as surfactin, iturin, bacillomycin, bacilysin, fengycinand zwittermycin in PCR studies. Further research is in progress to test theefficacy of elite rhizobacterial strains under cultivation conditions and tounderstand the mechanisms involved in the control of leaf spot pathogen.

22 Major Diseases Affecting Christophene Production in Trinidad Duraisamy Saravanakumar1, Aldo Hanel2, Augustus Thomas1, Naitram Ramnanan3 and Govind Seepersad4 1Department of Food Production, UWI 2Faculdade Integrado de Campo Mourão, Campo Mourão/PR, Brazil 3Plantwise, CABI, Trinidad and Tobago 4Department of Agricultural Economics and Extension, UWI A survey was carried out to acquire the latest information about theconstraints involved in the cultivation of Christophene (Chayote: Sechiumedule) in Trinidad. It was conducted in 2016 from different regions in theNorthern Range, covering 74 acres of land. The survey results indicatedthat fungal diseases pose serious constraints to the successful productionof Christophene on farmers’ holdings. The infected leaf, stem and fruitssamples from 10 random farms inclusive of main clusters were collectedand diagnosed in the lab. Laboratory analysis of the samples showed thatall the samples were infected with Didymella spp. [Syn: Stagonosporopsis][Anamorph: Phoma cucurbitacearum] which is reported to cause gummystem blight disease in most of the cruciferous vegetables. The samplesexhibited shot hole, stem blight and black rot symptoms in leaf, stem and fruitrespectively. The lesions were either circular or elongated and possessingminute, dark-coloured structures. The dark structures were confirmed aspycnidia in microscopic analysis. The cylindrical hyaline conidia wereobserved from infected samples and isolated pure cultures during microscopicanalysis. Out of 10 samples examined, 7 samples exhibited downy mildewinfection and 2 samples showed Cercospora infection. In addition, theanalysis of root samples showed nematode infection. Overall, the analysisof infected samples revealed the major occurrence of gummy stem blightinfection in all stages of Christophene production in Trinidad. These findingsinformed the development of a factsheet for farmers and a pest managementdecision guide, in collaboration with Plantwise, CABI, Trinidad and Tobago.

23Physiological Manifestations of Chilling Injury in Breadnut (Autocarpus camansi )Majeed Mohammed and Lynda Wickham Department of Food Production, UWI The breadnut or chataigne qualifies as a commodity with a uniqueflavour, high fibre content, high percentage of complex carbohydrates andthe ability to be utilized in a myriad of ways. However, the fruit is highlyperishable with a shelf life of not more than 2 days under ambient conditions.The breadnut is also very chilling-sensitive if stored below 50C to 6oC andchilling injury is a major limitation during transport, distribution, and displayunder refrigerated conditions. Studies were conducted to determine thephysiological manifestations of chilling injury when fruits were individuallyseal-packaged in low density polyethylene bags (LDPE) and paper bags(control) at 5-60C up to 8 days. Chilling injury symptoms of whole fruitsstored in paper bags were evident after 4 days at 5-60C. Appearance of visiblechilling injury symptoms were seen on the spines and skin which changedfrom a bright green to a dull green colour and eventually to a uniform browncolour over time. Other symptoms included water-soaked areas, translucencyof seed internal tissue, irregular brown coalesced sheet pitted lesions on seedsurface, invasive browning from seed perimeter into seed internal tissue,detrimental flavour changes, increased water loss and increased susceptibilityto secondary infections. These symptoms became more severe when fruits weretransferred to 20-220C for 1 or 2 days respectively. However, when fruits wereindividually seal-packaged in LDPE bags visible evidence of chilling injurywere not apparent until 8 days at 5-60C plus 2 days and more upon transfer to20-220C. Thus, the modified atmosphere created within the sealed bags as wellas the prevalence of high relative humidity delayed the appearance of visiblechilling symptoms. Despite the absence of chilling injury symptoms for fruitsin sealed polyethylene bags, measurements of reduced bioelectrical resistanceand increased electrolyte leakage suggested impairment to membrane integrityand the inverse relationship could therefore be a useful early detectionprocedure for the determination of the occurrence of chilling injury.Source: Tropical Agriculture (2016). Special Issue International BreadfruitConference: 149-155

24 Postharvest Quality Attributes of Twelve Ornamental Pepper Genotypes during Storage at Refrigerated and Non-Refrigerated Temperatures Mohamed, M.E.Sa; Mohammed, Mb; Bridgemohan, Pa and Baird, Jb aCentre for Biosciences, Agriculture and Food Technology, The University of Trinidad and Tobago bDepartment of Food Production, UWI Twelve ornamental pepper genotypes were selected to determinequality characteristics, storage potential and relative sensitivity to chillinginjury. The fruits were evaluated prior to storage at refrigerated and non-refrigerated temperatures for fresh weight, shape, number of seeds, placentafresh weight, skin colour, firmness, pH, total soluble solids (TTS), totaltitratable acidity (TTA), TSS: TTA and fruit dimensions such as length,width and pericarp thickness. Measurements were also taken for fruits ineach genotype that was sealed in low density polyethylene bags (LDPE)and stored for 15 days at 70C and 280C. These measurements includedpercentage fresh weight losses, percentage marketable fruits and percentagedecayed fruits. Chilling injury symptoms were rated for all genotypes after15 days at 70C and upon subsequent transfer for an additional day at 280C.Quality attributes varied among the 12 genotypes. However, genotypes3 and 4 demonstrated the best shelf life with fruits securing marketablevalues of 67% and 62% respectively after 15 days at 70C which was almosttwo-folds greater compared to those stored at 280C. While the same twogenotypes were chilling tolerant after 15 days at 70C, they succumbed tosevere chilling injury when transferred after 15 days plus 1 day at 280C.Source: International Research Journal of Natural and Applied Sciences4 (1): 189-206

25 Effect of a Biostimulant, Selected Agronomic Practices and Fruit Characteristics on the Relative Pungency in Caribbean Hot Peppers Puran Bridgemohan1, Musa El Sharief Mohamed1, Majeed Mohammed2 and Ronell S.H. Bridgemohan3 1Centre for Biosciences, Agriculture and Food Technology, The University of Trinidad and Tobago 2Department of Food Production, UWI 3Georgia College and State University, GA, USA Pungencyincapsicumfruitsisduetothebiosynthesisandaccumulationof the alkaloid capsaicin which adds flavour and colour to food in addition topharmaceutical properties. Studies were conducted to evaluate the effects ofa biostimulant, selected agronomic practices and fruit characteristics on therelative pungency in hot pepper. The trials were conducted in greenhousesand in full sunlight using several potting media namely: coconut fibre (CF),bagasse (B) and peat (P). Aqueous application of a biostimulant [BS] whichcontained boron (8.0%) and molybdenum (0.004%) was done weekly atvarying rates (5, 10, 15, and 20 ml/100 ml) at fortnightly intervals until firstharvest. Crop phenology and yield characteristics were conducted on fourvarieties namely Carvalho Hot (CH), Bhut Jaloka (BJ), Trinidad Scorpion(TS) and Trinidad 7-Pot (T7-P). The biostimulant on CH on fruit yielddisplayed a quadratic response. Peat and BS (5 ml) had the highest yield (72fruits/tree). In greenhouse, the effect of BS on yield displayed a quadraticresponse. CH in comparison with TS and T7-P (full sunlight/CF medium)was not significant for flowering and fruiting. Statistical modelling confirmedfruit lobes (L), seeds (S), pericarp (Pe) and placenta (Pl), as individual or ininteractions (L*S and S*P) had no influence on capsaicin and fixed oil yields.However, S*Pr*Pe significantly enhanced pungency in ripe peppers. All threeparts of the pepper fruit contributed to the overall pungency. The pericarp,seed and placenta are engaged in biosynthesis and storage of the capscinoids.

26 Sodium Hypochlorite Combined with Calcium Chloride and Modified Atmosphere Packaging Reduce Postharvest Losses of Hot Pepper Majeed Mohammed, Lawrence A. Wilson and Patrick I. Gomes Department of Food Production The University of the West Indies, St. Augustine A ‘systems approach’ was used to investigate changes that wouldenhance final produce quality and reduce postharvest losses of hot peppers.A survey of producers and traders was completed at seven market outletsin Trinidad. The major technological and socio-economic constraintsleading to quality deterioration and postharvest losses were investigatedin the survey and tested experimentally to develop solutions for qualitymaintenance and management. As fruits moved through the various steps inthe postharvest handling system in the various market outlets, there weredeclines in marketable quality resulting in qualitative and quantitativelosses. Postharvest losses varied according to market outlet. At all marketoutlets indiscriminate use of modified atmosphere packaging at temperatureextremes had deleterious effects on fruit quality. Pathological losses oftenoriginated from physical damages and exposure to chilling temperaturesresulted in secondary infections. Inadequate pre-harvest disease managementprotocols also contributed to multiple infections and disease proliferation.Entomological damages incurred prior to harvest contributed to lossesdue to ineffective pest management and poor coordination of postharvestsorting and grading practices. Other socioeconomic constraints such as lackof postharvest knowledge and skills, impediments to flow of informationto system participants, absence of postharvest training programmes, poorinfrastructure and lack of incentives made early prediction of damagedifficult. Against this background experiments were conducted using variousapproaches to quality management including postharvest dip treatments,modified atmosphere packaging and temperature management. Accordingly,it was demonstrated that hot peppers treated with a combined dip consisting ofsodium hypochlorite and calcium chloride and packaged in micro-perforatedhigh density polyethylene bags (HDPE) stored best at 100C after 25 days.Chilling injury damage of hot peppers in micro-perforated bags at 50C wasslower than in fruits in sealed HDPE bags or control fruits in paper bags.Source: International Journal of Research and Scientific Innovation, Volume III,Issue X, October 2016

27The Evaluation of the Allelopathic Effects of Bamboo Leaf Extracts on the Physiological Growth Parameters of Parthenium hysterophorus and Cyperus rotundus in Trinidad Terence Jack Department of Food Production, UWI Competition from White Top (Parthenium hysterophorus) and NutGrass (Cyperus rotundus) negatively impacts crop growth and productivity,resulting in considerable losses to vegetable producers in the Caribbeanannually. Traditionally, the method of control for these two noxious weed specieshas been primarily influenced by the economics and efficacy of commercialsynthetic herbicides. The injudicious use of these chemical formulations havethe deleterious effect of not only inducing herbicide resistance in the weedspecies but also increases the risk of groundwater contamination, impactsnon-target organisms and also poses potential a risk to human health and well-being. There is a need to urgently address these environmental and healthconcerns through the adoption of responsible weed management strategies,such as biological weed control. Amongst the different biological methods ofweed control, allelopathy has the potential to lead to reduced labour costs andincreased efficiency, without any adverse effects on the environment. Manyof the compounds produced by green plants that are not involved in primaryplant metabolism are observed to function as chemical warfare agents againstcompeting plants and pests. Many such natural compounds have the potentialto be exploited as herbicides or as leads for discovery of new herbicides. This study aims to investigate the efficacy of Bamboo (Bambusavulgaris) exudates on the growth and development of Partheniumhysterophorus and Cyperus rotundus. Research and development into environmentally friendlyherbicides which also safe guard the wellbeing of the consumer canfeed into particular niche markets as well as translating into savingfor the farming community. In addition to providing an alternativemechanism for weed management in traditional farm production systems,the success of this study can also help to address weed managementissues in landscaping, horticulture, pastures and other related sectors.

28Evaluation of Various Strategies for Management of Rice Sheath Blight Disease in Guyana Rajendra Persaud and Duraisamy Saravanakumar Department of Food Production, UWI Rice (Oryza sativa L.) is one of most important agricultural industryin Guyana that supports more than ten percent of the country populationdirectly and contributes greatly to the export earnings and the country GrossDomestic Product (GDP). Sheath blight disease of rice caused by a fungalpathogen, Rhizoctonia solani Kühn (anamorph), Thanatephorus cucumeris(Frank) Donk (teleomorph) which was once a minor disease, has of-latebecome a major disease inflicting heavy losses, and is considered to be animportant disease next to rice blast in different rice growing regions of theworld. Yield losses may range from 5.2 to 50.0% (Ou 1973), and under severeinfection loss amounts even up to 90 percent, depending on the environmentalconditions, the plant growth stage at infection, the extent of infection, andthe susceptibility of the rice varieties grown. The soil-borne nature of thepathogen and prolong survival of its sclerotia makes the control of thisdisease more difficult. However, the use of host resistance is one of the mosteconomical and environmentally sound strategy in managing sheath blightdisease. Though breading for resistance is the most practical and economicalmethod, no rice germplasm in the world has been found to be completelyresistant and/or possessing donor level resistant to the sheath blight pathogenwhich impedes resistant varietal development programmes (Roy 1993; Mewet al., 2004, Pinson et al., 2005). In view of this, the present research focuseson (i) identification of resistant, slow blighting and/or tolerant germplasmthat can be deployed in diseased prone areas (ii) evaluating the viable plantproducts, bio-agents and new generation pesticides for the managementof the sheath blight disease under Guyanese agriculture conditions. Identification of resistant, slow blighting and/or tolerant germplasm:One hundred and one rice (Oryza sativa L.) germplasm were evaluatedincluding one check cv. Rustic against the sheath blight (Rhizoctonia solaniKühn) disease under natural (i.e. no artificial inoculation field conditions atOnverwagt back and artificial inoculated condition within a semi-controlledscreen house condition at the GRDB, RRS at Burma over 2015 and 2016cropping seasons (Fig. 1). Over the five test environment two genotypesviz., FG12-56 and GR1631-35-16-1-2-1-1 consistently recorded reactionstatus ranging from immune to resistant; Five genotypes (GR1440-52-23-4-1-1-1-1-2-1-2, GR1602-6-41-1-1-2-1, IR-94, G11-08 and G98-135)ranged from very resistant to resistant and another seven (FG12-02, FG12-

2914, FG12-41, FG12-270, G11-103, FG07-35 and BR-444) observed withconsistently resistant reaction over all environment and period tested.Out these with sheath blight disease reaction status (scores) ranging fromimmune to resistant, thirteen showed slow sheath blight development withrelatively low AUDPC value lesser than 99.02, eleven showed reduction inthe apparent rate of disease development at least once to thrice over thetwo season of trials. On the other hand, genotype GR 1568-31-9-1-1-2-1and check cv. Rustic recorded susceptible reactions over all experiment. Themajority of remaining genotypes showed unstable and fluctuating reactionsranged from resistant to intermediate between resistant and susceptible.The AMMI ANOVA of the five environment showed that 52.98 % of thetotal sum of square (SS) were attributed to genotype (GEN) effect; 7.50 % toenvironment (ENV) effects and 39.52 % to genotype by environment (G x E)interaction effects; with the first principal component axis (IPCA 1) capturingabout 46.10 % of the interaction SS in 25.75 % of the interaction degreeof freedom (df), thus indicating the differences of the genotypes across theenvironment were sizeable. This further indicated that the resistance appearedto be somewhat influenced by the genotype by environment (G x E) interactionseffects. The AMMI analysis appeared to be useful and IPAC1 capturing realsignal in the data so the different biplot will further elucidate the performanceof the different genotypes with in the different environment conditions.Evaluation of botanicals, biologicals and new generation pesticides:The application of extract of Lemon Grass @15 % and Thick/ Broad leafthyme @15 % reduced the sheath blight infection under screen house andfield experiments. Similarly, the application of Bacillus sp. strain OG2L @2g /L showed low sheath blight disease incidence in rice when comparedto untreated control. The testing of new generation pesticides viz. Antracol70WP (Propineb) at 500g /ac., Nativo 75 WG (Strobilurine, Triazole,Trifloxystrobin, Tebuconazole) at 250g/ac., Serenade 1.34 SC (BiologicalFungicide (Baciillus subtalis cepa QST 713) at 400ml/ ac. and Fugione(Isoprothiolane) at 300ml/ac showed superior control against the ricesheath blight disease, positive influence in terms of rice plant growth, yieldparameters and increase in average grain yields as compared to the control. The current research is focused to explore, identify and developviable options for the effective management of sheath blight disease of ricein Guyanese agricultural conditions.

30 Exploring Strategies for Management of Rice Blast Disease in Guyana Rajendra Persaud and Duraisamy Saravanakumar Department of Food Production, UWI In Guyana, rice is one of the most important crops cultivated in anarea of 82,400 ha, with a total production of 823,800 tons per year (FAOSTAT,2014). The rice industry supports at least 10% of Guyana’s population andassumed greater significance in agriculture as it contributes more than20% of the agricultural GDP. The production of rice has been adverselyaffected by a number of biotic and abiotic stresses of which fungal diseasesreported to cause 20 to 70% yield losses. Among various fungal diseases,blast is one of the most serious constraints in rice production in Republicof Guyana where the disease has been very devastating and threatening thesustainability and survival of the rice industry (GRDB, 2013). The diseaseaffects different stages of crop starting from seedlings to harvest. Thus ithas become necessary to explore different options for the management ofthis disease. In view of this, the present research focuses on (i) identifyingresistant germplasm lines and understanding the expression of resistantproteins; (ii) evaluating the viable plant products, bio-agents and newmolecules for the management of blast under Guyanese agriculture conditions. 103 rice lines were evaluated against blast disease using modifiedupland blast nursery (UBN) test method. The experiment was conductedat at Canje (Gangaram), Black Bush Polder and Onverwagt of Guayanduring the first (spring) and second (autumn) crop, 2015 and second crop,2016 and selected entries confirmed during spring season, 2017. Thegermplasm FL-127 was consistent in expression of high blast resistancein all seasons tested at all locations. The use of Additive Main Effects andMultiplicative Interaction (AMMI), Genotype and Environment (GXE)interaction studies revealed the suitable environment for the screeningof blast germplasms. The analysis indicated the stable expression ofresistance by genotypes across all environments. It also revealed thatthe germplasm FL 127 has expressed high resistance and high stabilityacross all the environments tested against blast infection. This could bean elite source of resistance against blast disease to breed the hybrids.Highly resistant FL127 and highly susceptible Rustic germplasm werefurther selected to study the differential expression of proteins against blastinfection. 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE)followed by MALDI-TOF (MS) and TOF/TOF (tandem MS/MS) wereemployed to study the differential expression of proteins. The study showedthe up and down regulation of 78 proteins. Of which, twenty prominent

31proteins were characterized. The study showed the up-regulation ofpathogenesis related proteins, stress related proteins and photosynthesisrelated proteins such as beta-glucosidase, beta-glucosidase, Cellulosesynthase-like protein, 4-coumarate--CoA ligase and Ribulose bisphosphatecarboxylase. The peptide sequence could be a potential informationto develop the markers for screening of blast resistant germplasms.Evaluation of botanicals, biologicals and new moleculesThe application of extract of Black sage @10 %, Bael @15 % andMadar plant reduced the blast infection in field experiments. Similarly, theapplication of Bacillus subtilis strain OG2A and OG2L recorded low blastdisease incidence in rice when compared to untreated control. The testing ofnew generation pesticides viz. Antracol 70WP (Propineb) at 500g /ac., Nativo75 WG (Strobilurine, Triazole, Trifloxystrobin, Tebuconazole) at 250g/ac., Fugione (Isoprothiolane) at 300ml/ac showed superior control againstthe rice blast disease, positive influence in terms of rice plant growth, yieldparameters and increase in average grain yields as compared to the control.

32A status report on the water buffalo (Bubalus bubalis (Linnaeus, 1758)) industry in Trinidad A. Mohammed1, M. D.Diptee2, A. Persad1, R. Mohammed3, N. Lambie4 and S. Sieuchand1 1The University of Trinidad and Tobago 2School of Veterinary Medicine, Faculty of Medical Sciences, UWI 3Department of Food Production, UWI 4Ministry of Agriculture, Lands and Marine Resources, Trinidad and Tobago The objectives of this study were (a) to determine the number ofwater buffaloes/buffalypso (WB) in Trinidad, (b) to identify the constraints toWB production faced by private farmers and c) to update on the present statusof brucellosis in the country. The survey was conducted in 2012 to determinethe number of Water Buffalo (WB) at seventeen (17) privately owned farmsand three (3) Government farms in Trinidad; and to identify the constraints toWB production on the former. The number of WB recorded from the locationssurveyed was 1513, comprising 1039 from government owned farms and474 from 17 privately owned farms. The 17 privately owned WB farmerswere interviewed via a questionnaire and responses tallied to determine thechallenges to WB production. Animal numbers of WB ranged from 4-150 onprivate farms. The purpose for which the animals were reared was for milkproduction (6%, 1/17), meat production (48%, 8/17), work (29%, 5/17) andpets (19%, 3/17). The major concerns faced by private farmers were a shortageof labour, pasture availability and a lack of extension services. Farmers wereinterested in expanding their herd size and forming an association to addresstheir concerns. The number of WB in Trinidad appears to have declinedin 2012 compared to 2004. The major factor responsible for the declinewas a Brucellosis test and cull policy implemented by the Government. New and innovative strategies including reproductive bio- techniquesare needed to preserve the genetic legacy of the Buffalypso, as the WBcan significantly contribute to sustainable food production in Trinidad.Source: Tropical Agriculture (Trinidad) 94, (2), 2017, Pp 200-208

33 Mammary Activity and Litter Size in Captive Red-Rumped Agouti (Dasyprocta leporina) Singh, M. D., S. Singh and G. W. Garcia Department of Food Production, UWI The red-rumped agouti (Dasyprocta leporina) produces precocialyoung and is the most popular game species in several Neotropical countries,as it is among the most hunted and farmed wildlife. To conserve the agouti,as well as to increase production through wildlife farming, an understandingof its reproductive biology, including the relationship between litter sizeand teat functionality is crucial. In precocial mammals, as the red-rumpedagouti, maintaining maternal contact to learn foraging patterns may bemore important than the energy demands and nutritional constraints duringlactation and suckling may not play important roles when compared toaltricial mammals. Therefore, in this study we evaluated the relationshipbetween mammary functionality with litter size, litter birth weight, andparturition number in captive red-rumped agouti. Functionality was tested bymanual palpation of four pairs of teats from un-sedated females (N=43). Wecompared the average birth weight of all newborns, male newborns and femalenewborns among agoutis with different litter sizes and different parturitionsby one way ANOVA, while Pearson’s Chi-squared tests were used to detectrelationships between teat functionality, litter size, and parturition number. Results indicated that parturition number had no effect on themean birth weight of all young (F=0.822, p>0.05), male young (F=0.80,p>0.05) or female young (F=0.66, p>0.05) in the litters. Pearson’s bivariateanalyses revealed (i) no correlations (p>0.05) between teat functionalityand litter size and (ii) no significant correlations (p>0.05) between teatfunctionality and parturition number. This suggests that whilst all teats pairswere functional, newborn agouti may not rely on maternal nutrition forsurvival; an evolutionary strategy resulting in large wild populations; henceits popularity as a game species. The obtained results can be used to guidemanagement of captive agouti production systems as it may be possible towean neonatal agoutis almost immediately, returning the mother to breedingthereby reducing the parturition interval, increasing productivity in captivity.Source: Braz. J. Biol. 78-3, Accessed October 24 2017. http://www.scielo.br/scielo

34 Perimortality in a Captive Reared Agouti (Dasyprocta leporina) Singh, M. D. and G. W. Garcia Department of Food Production, UWI Perinatal mortality has been reported in cattle, swine, goats, sheepand rabbits; however, there have been no documented reports on thisphenomenon in agouti (Dasyprocta leporina). The agouti is a Neotropicalpolytocous rodent, hunted for its meat. This study reports on an incidentof perinatal mortalities in a captive reared agouti from the wildlife unit ofthe Faculty of Food and Agriculture. The pluriparous female agouti wasreared in captivity from birth and had delivered three (3) previous litterssuccessfully. These ranged from 2-3 young, with a 100% survival rate.This case presented a difficult labor, with delivery of three (3) healthyfemale precocious offspring (434g, 378g and 402g), and three (3) perinatalmortalities (285g, 368g and 300g). The female agouti appeared exhaustedand died during delivery. Postmortem results indicated a pale liver whichappeared severely affected with no particular pattern with respect to lobulararchitecture. Microscopic lesions on other organs were absent and therewas minimal subcutaneous and visceral fat present. The pathology reportcited dystocia resulting in secondary uterine inertia as the cause of deathof the female agouti. However, further investigations are necessary todetermine the possible causes of dystocia in pluriparous agoutis in captivity.Source: Singh, M. D., and G. W. Garcia. 2015. \"Perimortality in a Captive RearedAgouti (Dasyprocta leporina).\" Wildlife Biology in Practice 11, no. 2

35 Serological Evaluation of Ovarian Steroids of Red-Rumped Agouti (Dasyprocta leporina) During the Estrous Cycle Phases Singh, M. D.1, M. J. Morris, D. A. Guimaraes, G. Bourne and G. W. Garcia1 1Department of Food Production, UWI The objective of this study was to evaluate serum progesterone (P4)and 17β estradiol (E2) concentrations throughout the estrous cycle in the red-rumped agouti (Dasyprocta leporina).Atotal of eight multiparous, captive-bredfemales were bled throughout their estrous cycle via saphenous venipuncture,with E2 and P4 concentrations being measured via ELISA of the serumcollected. Serum E2 ranged from 1212-3500pg/ml with a peak value coincidingwith observed estrus. However, two additional peak values for E2 were alsorecorded, one each in metestrus and proestrus respectively. P4 concentrationsreached a maximum of 4.23 ng/ml, and increases in P4 immediately followedthe second E2 peak in metestrus. The highest concentrations of P4 wererecorded in mid diestrus; between days 23-25 of the 31-day cycle. Thisphase was the longest in the agouti, consisting of approximately 19 daysand accounted for 61% of the cycle. This study increased the basal scientificreproductive knowledge of this potentially valuable neo-tropical species.Source: Singh, Michele D., Michael J. Morris, Diva Anelie Guimarães, GregoryBourne, and Gary W. Garcia. 2016.\"Serological evaluation of ovarian steroids ofred-rumped agouti (Dasyprocta leporina) during the estrous cycle phases.\" Animalreproduction science 175: 27-32

36 Towards the Determination of a “Weaning Age” for the Intensive Production of the Agouti (Dasyprocta leporina) Riyadh Mohammed, Uppoor Krishnamoorthy, Gary Wayne Garcia Department of Food Production, UWI The objectives of this study were to determine; 1) The best age atweaning agouti offspring to facilitate survival and good growth and 2) Toselect the best weaning age to allow the dam to re-conceive faster and tolose the least condition post-partum. Eighty parturitions were recorded (April2015-April 2017) along with weights of 136 offspring. After parturition,offspring were left with their dams for 1, 2, 3 and 6 week periods. Resultsshowed that there was a significant difference between the final weights of alloffspring (P < 0.003) and all dams (P < 0.001) at the 12th week after birth and 8weeks after parturition. Litter size had no significant effect on the final weightof offspring in the post weaned period (P > 0.369). However, litter size didhave an effect on the successive parturitions (P < 0.001). There were significantinteractions between dams’ age and parity number (P < 0.001) and paritynumber and birth weight (P < 0.019). The average litter size was 1.7 offspring per litter. The Average dailygains regardless of the weaning age were; singles 18.26 g/d, doubles, 18.05g/d, triples 15.28 g/d, and quadruples 14.14 g/d respectively. There were 45double births, 27 single births, 5 triple births and 1 quadruple birth respectively.Of the 136 offspring, 75 were males, and 61 were females. All males born hadan average birth weight of 183.52 g/d while females’ average birth weightswere 186.51 g/d. The Average Daily Gain for males regardless of pre weaningages were 18.14 g/d and females 18.36 g/d. Dams that experienced weaningages of 6 weeks, 3 weeks, 2 weeks and 1 week had an average body conditionof -4.7 g/d, -1.6 g/d, -1.6 g/d and -1.5 g/d respectively. Weaning ages haddifferent effects on the conception and successive parturition and are asfollows; at 1 week pre weaning had an average of 15.89 weeks until the nextparturition, at 2 weeks weaning dams gave birth 17.86 weeks after, at 3 weeksweaning dams gave birth 20.84 weeks after and at 6 weeks weaning damsgave birth 23.94 weeks after. From the 4 litter sizes; single, double, tripleand quadruple type births, a percentage was calculated using the mother’sbody weight at birth and the offspring weight at birth and at week 12. The study concluded that the best age at weaning is at 1 week old,which showed no negative effect on growth in the post weaned period amonglitter sizes and had the fastest reconception time for dams postpartum.

37 Effect of Supplementary Feeding of Commercial Sheep Ration orSprouted Black-Eyed Bean to Suckling Barbados Blackbelly Lambs on Milk Intake and Growth Performance Ali, S. A.1, Krishnamoorthy, U.1, Gopalan, K.2 and Paul, A.1 1Department of Food Production and 2Department of Agricultural Economics and Extension, UWI Barbados Blackbelly sheep, although known for high fecundity, thesurvivability and growth performance of lambs are often affected, perhapsdue to inadequate milk produced by the ewes. This study was conductedto assess if feeding sprouted black-eyed bean (SBB) as a supplement tosuckling newborn lambs has any beneficial effect on milk consumptionand its impact on growth in early phase of life. Further, milk productionpattern and body weight dynamics in lactating ewes were also studied.Twenty-two Barbados Blackbelly lambs were separated from the ewes 24hours after birth, and randomly allotted to one of the two groups. The lambswere allowed with the dam on the first day. From day 2, milk feeding regimewas restricted to two feedings per day. Milk consumption by the lambs wasobtained using a ‘weigh-suckle-weigh’ method, wherein, the lambs wereallowed to suckle the dam for 20 minutes. The difference in weights pre andpost suckling was regarded as the amount of milk consumed. Lambs in GroupI were offered commercial sheep ration (CSR), while the lambs in Group II,sprouted black-eyed beans (SBB) separately as creep feed from day 2 to day42. The lambs were weighed pre- and post-suckling from day 2 to day 42. The ewes were fed with fresh, chaffed tanner grass (Brachiariaarrecta) ad libitum and commercial sheep ration at the rate of 1kg perewe per day. The ewes were weighed post-partum day 2 and day 36, andhand milked once in a week for analysis of chemical composition of milk.The estimated means for daily gain in body weight (g) of lambs in the agegroup week 1-3 and week 4-6 respectively for the CSR and SBB groups were62.71 ± 0.80a, 61.76 ± 0.80a, 63.85 ± 0.80ab, 65.15 ± 0.80b. The estimatedmean for the SBB week 4-6 was significantly (P < 0.05) higher suggesting thatfeeding of SBB had an impact on body weight gain in lambs during week 4-6. The overall average daily milk production by the ewes for 6 weeksof lactation was 1009 g, with a peak yield of 1151 g/day in the fourth week.The total solids in milk ranged from 11.96 to 13.36 %, and fat from 2.31 to 3.49%. All ewes showed a body weight loss varying from 1.64 to 3.5 kg, betweenweek 1 and week 5 with an overall weight loss of 2.9 kg in 36 days of lactation.SBB feeding can be recommended for suckling lambs between 4 to 6 weeks of age.

38The Effect of Partial Replacement of Commercial Sheep Ration withTrichanthera gigantea Leaves on Dry Matter Intake, Weight Gain, SerumEnzymeLevelsandCarcassCharacteristics inBarbadosBlackbelly Lambs Balraj, D.1, Krishnaoorthy, U.1, Nayak, S.2 , Paul, A.1 1Department of Food Production 2Department of Preclinical Sciences, Faculty of Medical Sciences, UWI There is a need to find cheaper substitutes for commercialsheep ration (CSR). The use of locally available protein rich foragescould make small ruminant production in Trinidad and Tobagosustainable and globally competitive. Since Trichanthera gigantea(TG) is one such protein rich forage, this study was undertaken toassess the potential of TG leaves (TGL) as a partial substitute for CSR. The 27 lambs used were divided into nine groups of three lambsand each group was housed in separate pens measuring 5 m x 6 m. In acompletely randomized design the pens were allocated to three differentdiets: (i) Tanner grass (Brachiara arrecta) offered ad libitum + CSR @ 2%of the body weight as a supplement to provide adequate energy, proteinand other nutrients as specified by the NRC (1975). – TGL-0 (ii) Tannergrass offered ad libitum + 20% of CSR replaced by TGL on dry matterbasis – TGL-20 and (iii) Tanner grass offered ad libitum + 40% of CSRreplaced by TGL on dry matter basis –TGL-40. The feeding trial lasted for11 weeks. In the last week of feeding trial, blood samples were collectedfrom the jugular vein to determine serum levels of total protein, albumin,alanine amino-transferase (ALT) and aspartate amino-transferase (AST). Onthe last day of the feeding trial, four lambs from each group were randomlyselected for slaughter to determine carcass yield and carcass components.The CSR contained 14.6 % crude protein (CP), 33.9 % NDF and 22.3% ADF.The respective components (% DM) in TGL were 18.1, 28.8 and 21.3 andin tanner grass, 6.5, 55.9 and 29.6. The total DMI (kg/head/day) in groupsTG-0, TG-20 and TG-40 were 0.57, 0.45 and 0.51 respectively. The DMIas a proportion of body weight were respectively 3.05, 2.71 and 2.83 and thedifferences among groups was not statistically significant. Average daily gain(ADG, g/day) for lambs in TG-0, TG-20 and TG-40 were 60.5, 30.8 and 18.5respectively. The TG-0 had a significantly higher weight gain than the TG-20and TG-40 (P < 0.01). The total protein in serum for TL-0, TGL-20 and TGL-40 were respectively 7.00, 6.43 and 7.04 g/100 ml and the difference was notsignificant. Similarly serum AST and ALT levels did not differ significantlyamong three groups. The carcass yield expressed as dressing percentage forTGL-0, TGL-20 and TGL-40 were 35.4, 40.3 and 37.4 respectively and thedifference was not significant.

39 Assessment of Saijan (Moringa Oleifera Lam) as a Feed Resource for Rabbits (Oryctolagus Cuniculus) in Trinidad And Tobago Maharaj R., Krishnamoorthy U., Garcia G., Paul, A. Department of Food Production, UWI While rabbit rearing is gaining popularity in Trinidad and Tobago,the cost of rabbit production is increasing. This study (three parts) wasinitiated to assess prevalence of morphological differences in Moringaoleifera plants in Trinidad, and explore its potential as a feed resourcefor rabbits. Part one involved morphological studies, wherein samplesof Moringa leaves, flowers and pods were collected. Part two involvedobservations on germination, establishment of a Moringa plot for foliageproduction and analysis of harvested leaves for nutrient composition. Chemical analysis of Moringa oleifera leaves and twigs (MOLT)revealed 23-30% crude protein, 13-15% crude fibre and 3-6% crudefat, indicating that it can serve as a good source of forage for livestock.Part 3 of the study included feeding trials to determine the effect differentcombinations of MOLT and CRF on the weight gain and carcass quality ofweaned rabbits. The study was conducted using 50 rabbits of mixed breedsweaned at 5 weeks. The weaned rabbits were grouped into 10 blocks of fiverabbits of similar body weight within each block. The five diets were (i) 20gcommercial rabbit feed (CRF) and 150g fresh Moringa oleifera leaves and twigs(MOLT) (T1), (ii) 40g CRF and 120g MOLT (T2) , (iii) 60g CRF and 110g MOLT(T3), (iv) 80g CRF and 100g MOLT (T4), (v) 100g CRF and 0g MOLT (T5).The feeding trial continued for seven weeks during which daily intake of CRF,MOLT were measured and the rabbits were weighed once a week. At the endof the trial rabbits were slaughtered from each group to quantify carcass yield. Significant differences (P < 0.01) were observed among treatmentsfor total dry matter intake (DMI, g/day), T1 40.6, T2 52.5, T3 64.9 and thehighest for T4 and T5 (71.8 and 71.2 respectively). The mean daily weightgain (g/day) differed significantly (P< 0.01) among treatments. The weightgain for T1, T2, T3, T4 and T5 were 8, 14, 20, 22 and 22g respectively.The feed conversion ratio (FCR) differed significantly among treatments (P <0.01) with T1 having 4.9 compared to T2 (3.7), T3 (3.2) T4 (3.2) and T5 (3.3).Significant differences (P<0.01) were observed among treatments for meandressing percentages. Animals belonging to the T1 had the lowest dressingpercentage (43.6%), followed by T2 48.7%, T3 51%, T4 52.1% and T5 52.4%.The dressing percentages of T3, T4 and T5 were similar, however they differedfrom the dressing percentages of the T2 and T1 significantly. Mean perirenalfat weight differed among treatments (P < 0.01) with rabbits who were fed on

40the T5 diet comprising of only CRF having greater amounts of perirenal fat(61.7g) when compared to animals who were fed the higher forage diet T4(51g), T3 (40.4g), T2 (19.9g),T1 (10.2g). Perirenal fat weight of the T3, T4 andT5 were similar, however they differed from that of the T2 and T1 significantly. The results suggested that MOLT can be used to partially replacecommercial rabbit feed to the extent of 28% on a dry matter basis.

41Research Summaries on Breadfruit and Chataigne (Breadnut-Fruit)1. Breadfruit Orchard Management – Pruning, Cultivar Selection and Plant Arrangement Laura B. Roberts-Nkrumah, and Michael Gloster Department of Food Production, UWI Work on breadfruit orchard management addresses constraints tosustainable commercial production. One key constraint is the considerableheight of mature trees of the commonly existing cultivars in the Caribbean. Thecurrent research investigations have focussed on two approaches to managingbreadfruit tree height – pruning and cultivar selection. Both factors are alsoinfluenced by tree arrangement, therefore, this aspect was also examined.In traditional on-farm production systems with breadfruit, the trees are grownon the borders or in mixed cropping systems especially with other tree crops.One major disadvantage of the existing Caribbean cultivars growing inthese systems is that they become quite tall which makes harvesting fruitsin the upper canopy difficult and increases postharvest losses. Therefore,tree height management is important for the sustainable commercialbreadfruit production. Pruning is the most commonly used cultural practicefor managing tree height in fruit trees but no studies were previously doneto evaluate the efficacy of pruning breadfruit trees. However, becausepruning can increase the cost of production, there is also need to examinewhether the use of cultivars that may be shorter than the local cultivars isa potentially less costly approach to tree height management. Accordingly,these studies in Trinidad and Tobago have been conducted on-farm atthe University Field Station, Valsayn and at the PCS Nitrogen TrinidadLimited Model Farm in Couva using the local ‘Yellow’, a tall cultivarand ‘Ma’afala’, a recently introduced cultivar that is reputed to be shorter.The results of studies on tree height management using different levels ofpruning on bearing 6 year old ‘Yellow’ and ‘Ma’afala’ trees at the Couvasite showed that one year after two consecutive annual prunings therewas no significant effect on either tree height or canopy width because ofthe growth of new branches on the pruned trees especially on ‘Ma’afala’trees. Over all pruning treatments, the mean height of ‘Yellow’ (5.2 m) wassignificantly (p<0.001) taller than that of ‘Ma’afala’ (3.9 m), while the latterhad a significantly (p<0.001) wider mean canopy width (4.0 m) than ‘Yellow’and produced more branches at all levels of pruning. The results suggestedthat the location of pruning cuts, time of pruning, soil moisture availability

42during the period after pruning and possible differences between cultivars inwater requirements were all factors that affected the response to pruning ofmature trees. Studies were also conducted on young ‘Yellow’ and ‘Ma’afala’trees at the same locations using different levels of pruning. All plants the twopruned treatments were headed back four months after planting and those inthe head back and thin treatment were thinned four months later. All prunedtreatments were repeated 10 months later. The results at 21 months afterestablishment confirmed that during early growth ‘Yellow’ is significantly(p<0.001) taller than ‘Ma’afala’ but that the latter cultivar was significantly(p<0.001) more branched. The control (unpruned) trees were significantly(p<0.001) taller and had more than trees in both pruned treatments. Over alltreatments and both cultivars, the trees at Valsayn showed superior vegetativegrowth than those at Couva. Over all pruning treatments and cultivars, two tree arrangements,rectangular and triangular were used in the studies with the young trees.Vegetative growth in terms of tree height, branch number and leaf number washigher in the rectangular than in the triangular arrangement. These studiesare continuing to evaluate the effect of pruning, cultivar and tree arrangementon fruit yield of both cultivars. 2. Breadfruit Orchard Management – Disease Management-Fruit Rot and Tree DeclineLaura B. Roberts-Nkrumah, Mark Wuddivira, Oral Daley, Frankie Solomon, Gem Thomas Department of Food Production, UWIBreadfruit (Artocarpus altilis (Parkingson) Fosberg) is not usually consideredas a crop that is prone to diseases, especially where it is not being grownfor commercial purposes. However, two diseases that occur on breadfruitin the Caribbean can impact commercial viability. Fruit rots caused by arange of pathogens e.g. Colletotrichum spp and Phytophtora spp can reducemarketability of the fruits. A more serious disease is Tree Decline that may beinduced by biotic or abiotic factors or both, and can lead eventually to tree death.Fruit rot - preliminary studies on fruit rots over a two year period focussedon understanding the relative importance of fruit rots to unmarketability ofharvested fruits, and the effect of cultivar and season of fruit production onthe incidence of fruit rot. Thirty nine accessions consisting of Caribbeanand recently introduced germplasm in the Breadfruit GermplasmCollection at the University Field Station at Valsayn were evaluated.The results indicated that over all accessions, 46.7% of all harvested fruit were

43unmarketable and that fruit rots appearing on 63.4% of the unmarketable fruit.Among the accessions the mean incidence of fruit rot was 32.5% (± 1.78),and that there were very highly significant (p<0.001) differences among theaccessions with 23%, mostly Caribbean accessions, producing 50% or morefruits that were infected with fruit rots. Two of the new accessions, ‘Toneno’and ‘Pii piia’ produced no fruits with fruit rots over the two year period. Theincidence of fruit rot was tended to be higher on fruits born during the rainyseason. These results indicate that the fruit rots are the major contributorto serious losses of marketable yield of breadfruit especially during the wetseason on some cultivars. Longer term studies are continuing to confirmthese results and to determine the extent to which the incidence of fruit rotsmay be alleviated by cultivar selection and improved crop management.Tree decline – This disease was previously reported on breadfruit treesover 20 years old in the Caribbean and the loss of tree vigour and ultimatedeath was attributed to abiotic factors, especially water stress, and pathogensincluding nematodes. This syndrome is of greater economic importancewhen it occurs in trees that have not yet matured or are in the early maturestage. Chataigne (A. camansi), a close relative of breadfruit, Therefore,our studies have been conducted on during the early stages of breadfruitgrowth and development and have used preliminary pot studies and morelong-term field studies to compare the effect of cultivars on the physiologicalresponses to water logging and the survival of breadfruit plants graftedon chataigne rootstocks under different field conditions. The efficacy ofselected agrochemicals in controlling the disease is also being examined.Physiological responses to waterlogging – The results of pot studies revealedthat seedlings of three commercially available cultivars in Trinidad and Tobago‘Yellow’, ‘Musunwa’and ‘Ma’afala’were all susceptible to waterlogging withplant death after 5 weeks being highest in ‘Ma’afala’ (40%) compared withthe other cultivars (20% each). Photosynthetic efficiency, root mass, total leafnitrogen and leaf, stem and root dry weights were significantly (p<0.05) lowerunder waterlogged conditions than under well-drained conditions. ‘Ma’afala’had a significantly (p <0.05) higher percentage root loss than the other cultivars.Survival of grafted plants – Grafted plants of breadfruit cultivars ‘Yellow’,‘White’ and ‘Macca’ were established on a cambered bed at the UniversityField Station, Valsayn where the soil is the comparatively well-drainedRiver Estate Loam soil and at a site prone to waterlogging at the PCSNitrogen Trinidad Limited Model Farm in Couva on the poorly drainedPerseverance Clay. Five years after establishment, the survival rates atValsayn were 100, 80, 80, and 60 %, compared with 50, 40, 31 and 22% at Couva, for chataigne, ‘Macca’, ‘White’ and ‘Yellow’, respectively.These results indicate that while grafted plants can survive, soil conditions

44and cultivar both affected the survival rate. Comparisons with ungraftedplants are needed to determine the efficacy of grafting these cultivars. 3. Breadfruit Orchard Management – Crop Phenology and Growth Responses to Selected Plant Growth Regulators Carol Ann Mc Kenzie, Laura B. Roberts-Nkrumah Department of Food Production, UWIThe seasonality of production is one of the major constraints to thecommercial development of breadfruit. Studies were undertaken to evaluatethe efficacy of using phenological differences among cultivars selection andthe application of selected growth regulators on induction of reproductivegrowth to extend the production period for breadfruit in Trinidad. The results showed that vegetative growth in breadfruit wascontinuous but with periods of high vegetative growth alternating periodsof slow growth associated with the maximum air temperature and fruit load.Female infloresence production which marked the commencement of fruitingwas significantly related to solar radiation receipt. Based on their fruiting andharvesting patterns, any one of the recently introduced cultivars, ‘Porohiti’,‘Pii piia’, ‘Mein Padahk’, ‘Ma’afala’ and ‘Toneno’ may be used with thelocal cultivars, ‘Yellow’ and to extend the period of breadfruit availability.Environmental conditions during the dry and wet seasons of this study were notconducive to the prolonged periods of high rates of photorespiration necessaryfor foliar applications of methanol to affect vegetative and reproductivegrowth. The effects of multiple foliar applications of low rates (333.3 mg.L-1) of ethephon and paclobutrazol on slowing vegetative growth were notsufficiently long term to stimulate reproductive growth. Ethephon also causeleaf loss, and inhibited leaf area development and also suppressed flowering.Itwasconcludedthatcontinuousshootgrowthwasnecessarytosupportvegetativegrowth of breadfruit and that cultivar selection might be a better approach thanthe use of growth regulators for extending the production season of breadfruit. 4. Breadfruit - Propagation Laura B. Roberts-Nkrumah, Judy Rouse Miller*, Mr Frankie Solomon Michael Gloster Department of Food Production *Department of Life Sciences, UWIThe most widely consumed breadfruit cultivars are seedless and reproducevegetatively. The availability of adequate quantities of uniform, high qualityplanting material in the shortest possible time to facilitate establishment

45of commercial plantings has been identified as a constraint to commercialbreadfruit production. Additionally, it is recognised that even if this problemis resolved, in areas where tree decline occurs, planting material tolerantor resistant to the causal factors of this disease is necessary. Therefore,breadfruit propagation research at UWI has been geared to address both theproblems of availability of planting material by macro- and micropropationmethods and the production of disease tolerant materials by graftingbreadfruit scions to chataigne tree decline resistant or tolerant rootstock.While the use of root cuttings as planting material is well-known, there isno information on the performance of grafted plants or of tissue culturematerials, therefore, these materials have been evaluated in pot and field trials.Adventitious shoot production on root cuttings – Root cuttings are themost successful macropopagation method for seedless breadfruit cultivars,but typically only one new plant is produced from each cutting, whichlimits the multiplication rate. Studies were conducted to determine theadventitious shoot production potential of root cuttings and the effectsof cultivar and cultural practices on shoot production. Root cuttings5 – 7 cm in diameter and 15 cm long of the local cultivars, ‘Yellow’and ‘White’ were placed in propagating bins and subjected to differentlevels of exposure and fertiliser and different shoot harvesting methods.The results showed that more than one shoot could be obtained from oneroot cutting. Over 34 weeks, ‘Yellow’ produced significantly (p<0.001) moreshoots than ‘White’ with the mean shoot number per cutting of 31 and 15,respectively. Root cuttings with the upper surfaces exposed produced moreshoots than those with that were completed buried. Shoot production wasalso higher when semi-hard shoots were harvested than when harvesting wasdelayed. Application of foliar fertiliser and late shoot harvesting increasedshoot mortality. Therefore, with adequate exposure, early shoot harvestingand disease management, root cuttings can be used more efficiently toachieve higher levels of planting material production over longer periods.Grafting – Previous reports on grafting breadfruit indicated that the resultswere generally poor. Therefore, studies were undertaken to identify thekey factors influencing the successful development of the graft unionbetween breadfruit scions and chataigne grafts. The effects of plant growthregulators, rootstock age, cultivar of the scion, season of scion collectionand the morphology and anatomy of the rootstock and scion were evaluated.Based on the results of studies of chataigne rootstock age, all subsequentexperiments using breadfruit scions taken from stock plants in the field weregrafted on 6-week old chataigne seedlings. Scion materials were taken fromjuvenile trees of the breadfruit cultivars ‘Yellow’, ‘White’, ‘Macca’ andchataigne was used as the control. The application of the growth regulators,

466-benzylaminopurine (BAP) at 200 ppm and indole butyric acid (IBA) at 100and 200 ppm significantly (<0.05) reduced the survival rate of grafted plantscompared with the control. The survival rates of grafted plants were highestfor those with chataigne or ‘White’ scions and for scions collected in the wetseason. With improved scion quality collected in the wet season and a post-grafting environment with temperature between 24 to 29 0C and RH above 90%survival rates of 97, 83, 80 and 80% were achieved for grafted plants of ‘White’,‘Macca’, ‘Yellow’and chataigne. It was shown that the relatively higher successachieved with ‘White’ was related to the best match of the cambial regionsof the scion among breadfruit cultivars and the cambium of the rootstock. These studies revealed that juvenility of both scion androotstock was critical to the successful formation of the graft union.In order to remove the limitation of environmental conditions on thequality and therefore the time of scion collection for grafting, and tominimise the bulging at the graft union that was observed when scionobtained from field-grown juvenile plants, epicotyl grafting of 1 to 4weeks old chataigne seedlings was done with micro-grafted breadfruitshoots. The survival rate of the grafts on seedlings of all ages was 100%.Nine-month old grafted plants were established successfully in the fieldand fruiting began at 19 months after establishment on ‘Macca’, and at30 months on ‘Yellow’ and ‘White’ that was comparable with the timeearliest times reported for plants growing from adventitious shoots.Comparison of growth of different types of planting materials – Pot studieswere established to evaluate the growth of breadfruit plants by threepropagation methods in two breadfruit cultivars. Fourteen month old plantsconsisting of excised adventitious shoots and grafted on chataigne rootsstocks of the ‘Yellow’ cultivar were grown at the University Field Station atValsayn and at the PCS Nitrogen Trinidad Limited Model Farm at Couva inpots filled with soil from the site. The plants showed continuous increase inheight and girth over 15 months with seasonal fluctuation in rates. Branchingwas periodic. Plant height and girth of the plants from the adventitiousshoots were greater (p<0.01 and 0.03, respectively) than those of the graftedplants. Tree girth and leaf retention on plants at Valsayn were higher thaton those at Couva, but the latter had more branches. Therefore, the typeof planting material and the location influenced early vegetative growth.

47 5. Physiochemical Characteristics of Breadfruit Flour and Starch Jacklyn Broomes, Neela Badrie and Laura B. Roberts-Nkrumah Department of Food Production, UWIThe Caribbean is chronically insecure in terms of its food and nutritionstatus because the region relies heavily on imported food. Breadfruit(Artocarpus altilis (Parkinson) Fosberg) can contribute to food andnutrition security but is generally underutilized. One of the challenges togreater breadfruit consumption is that mature fruits have a short shelf-lifeof only 1 – 3 days at ambient temperatures. Conversion of fresh fruit toflour can alleviate this problem. Breadfruit flour lacks gluten which is ahighly desirable characteristic for consumers who are gluten intolerant,however, in the absence of gluten, the amylose content of the starch is avery important determinant of the end uses of breadfruit flour. There islimited information of the nutritional composition of breadfruit flour, starchcontent and the physicochemical and functional properties of the starch. The objectives of these studies were to address these gapsand to examine whether these characteristics were influenced bycultivar. Studies were conducted using 11 cultivars from the BreadfruitGermplasm Collection at the University Field Station at Valsayn.The results showed that cultivar influenced most of the characteristics. Theedible portion ranged from 58% to 79% with a mean of 68% and flour yield fromthe edible portion ranged from 29 to 51% with a mean of 33.5%. The mean starchyield from the edible portion was 13.5% with no significant cultivar effects.The nutritional analysis of breadfruit flour indicated that carbohydrates werethe major nutrients, it was a very good source of dietary fibre and it suppliedappreciable levels of potassium, calcium and iron. The flour from differentcultivars differed significantly in the mean content of some macronutrientscontent (g/100 g), but not of carbohydrates, energy and dietary fibre asfollows: carbohydrates – 75% ; energy – 342 kcal; crude protein – 4.1 %(range - 3.4 to 5.5 %; crude fat – 0.9 (range - 0.4 to 1.6%); dietary fibre – 9.9 %.The results showed that the amylose content in breadfruit was low to verylow. Among the cultivars with low amylose content were the Caribbeancultivars ‘White’, ‘Kashee Bread’, ‘Macca’, ‘Timor’and ‘Cassava’; a recentlyintroduced cultivar, ‘Pii piia’ was also in this group. Those with very lowamylose content included the Caribbean cultivars ‘Yellow’, ‘Creole’, ‘HopeMarble’ and ‘Common’; the recently introduced ‘Ma, afala’ was also in thisgroup. Therefore, in terms of end uses with pure breadfruit flour, the flourswith the very low amylose content can be used in products in which gellingis not required whereas those with low amylose content may be used for