Location: Tropical Crops and Germplasm Research
Title: Five-year agronomic and phenotypic data summary for a replicated cacao (Theobroma cacao L.) germplasm collection Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 14, 2012
Publication Date: N/A
Technical Abstract: Loss of genetic diversity found in centers of origin necessitates the establishment of ex situ germplasm collections for long-term conservation. Cacao genetic resources have been acquired, preserved and evaluated at the USDA-ARS, Tropical Agriculture Research Station in Mayaguez (TARS), Puerto Rico for over 80 years. Beginning in 2001, a consolidated new planting was re-established with 154 unique germplasm accessions, held at the time, in a completely randomized block design. Field characterization efforts began January 2007, with monthly data being collected on disease resistance and production. A subset of randomly selected pods for each accession, at each harvest, was evaluated for other important agronomic and phenotypic traits including, pod index values, length, width, weight and shape of the pod, weight of the shell, color and number of seeds per pod. Data analysis showed peak of production generally was during the cooler winter months (December-February). Disease ranged from 2.5% for the most resistant accession to close to 50% for the most susceptible accession. Pod index values ranged from 51.6 to 14.0. Production, which was calculated by taking the average number of healthy pods per tree per year and multiplying it by the accession’s pods index, ranged from 0.13 for the least productive to 1.94 kg/tree for a local hybrid selection ‘TARS 27’. Under existing TARS cacao germplasm cultural and management practices, some of the most productive clones yielded approximately 3000 kg/hectare. Characterization data for all accession evaluated is being loaded and will become available through the USDA, National Plant Germplasm System, Germplasm Resource Information Network (GRIN-Global) database http://www.ars-grin.gov/. Accessions being characterized are available for distribution in limited quantities for research purposes.