Planting date and genotype effects on tepary bean productivity

Abstract

Our objective was to evaluate production potential of eight tepary bean (Phaseolus acutifolius A. Gray) genotypes and three planting dates. Significant variation (P < 0.05) existed among eight genotypes and three planting dates in 1997 and 1998. The genotype x planting date interaction was nonsignificant (P > 0.05) for seed yield and harvest index. Seed yields of eight genotypes, when averaged over three planting dates and 2 years, varied from 1618 to 1988 with a mean of 1816 kg.ha-1, indicating that tepary bean is adapted to Virginia's agro-climatic conditions. The harvest index (ratio between seed and total plant weight, expressed as percentage) ranged from 38% to 47%. Seed weight varied from 12.6 to 18.8 g with a mean of 14.5 g. Genotypes with tan-colored seeds had significantly larger seed than those with black or white seeds. Planting dates significantly affected seed yield, seed weight, and harvest index. The highest seed yield (2239 kg.ha-1) and harvest index were obtained from the late May plantings.