Production of black bean genotypes under residual moisture and terminal drought conditions.

Abstract

In Veracruz and Chiapas, autumn-winter growing cycle bean crops suffer periods of drought during the reproductive stage, causing low yields. The aim of this study was to determine the yield of bean genotypes evaluated under conditions of residual moisture and terminal drought during the autumn-winter 2013-2014 growing cycle, in the localities of La Candelaria, Medellín, Veracruz; Ixtacuaco Experiment Station (CEIXTA), municipality of Martínez de la Torre, Veracruz; and Centro de Chiapas Experiment Station (CECECH), municipality of Ocozocoautla, Chiapas. Eleven advanced bean lines were evaluated and compared with the control varieties Negro Tacaná and Negro Jamapa in a randomized block experimental design with three replications. The response variables were days to average flowering, days to physiological maturity, weight of 100 seeds and grain yield. In La Candelaria and the CECECH, both with terminal drought occurrence, the four response variables were significantly lower than those obtained in the CEIXTA, without drought stress. The SEN-56, SCN-2, SEN-70 and NCB-229 lines had significantly earlier average flowering in the three test locations, which on average occurred before 35 days after sowing. The first three lines also showed shorter time to physiological maturity, which on average was less than 71 days. The SCN-2 line produced the highest average weight of 100 seeds (27 g), which was significantly higher than those obtained with the other genotypes, which had weights below 25 g. In addition, SEN-70, NGO‑17-99 and Jamapa Plus, along with four other lines obtained an average yield of more than 1000 kg ha-1, which was significantly higher than those of the varieties Negro Jamapa and Negro Tacaná. SEN-70 was the highest-yielding line with and without occurrence of terminal drought.