TERMINAL WATER STRESS IMPOSED TO IDENTIFY DROUGHT TOLERANT MESOAMERICAN BLACK COMMON BEAN BREEDING LINES IN SOUTHERN MEXICO

INTRODUCTION: Productivity of the dry bean crop is low in the humid tropical environments of southeastern Mexico, due in large part to the effect of different biotic and abiotic factors which reduce grain yield. The most important abiotic factor is the presence of terminal drought that occurs frequently after flowering, during pod filling stages and physiological maturity (Acosta-Gallegos et al., 1998), particularly in the crop season with residual moisture, which restrict yield and cause partial and severe losses in commercial crops. The development of improved varieties with resistance to this environmental factor is a viable alternative to increase yields of beans under conditions of water stress (Frahm et al., 2003). The objective of this study was to field test recombinant inbred Mesoamerican black dry bean lines for their resistance and/or adaptation to terminal drought and high plant relative yield efficiency grown under nonstress and water stress conditions in tropical southeastern Mexico