From the field to the pot: phenological, agronomic, and cookability traits of common beans ( Phaseolus vulgaris L .) grown in contrasting climatic regions in Uganda.

Abstract

Common beans ( Phaseolus vulgaris L.) phenotypic characteristics, cooking quality, and resilience to climate change are pivotal in making varietal choices of this crop in Uganda. This study evaluated 247 common bean genotypes across two climate-diverse regions, Mubuku (883 mm precipitation) and Namulonge (1300 mm precipitation), with 199 genotypes evaluated for phenological, agronomic, and cookability characteristics. The mixed model analysis indicated significant differences in both genotype and genotype x environment effects for days to flowering and maturity, number of pods per plant, 100-seed weight, seeds per pod, and per plant (P < 0.001). The environment significantly influenced days to flowering and maturity (P < 0.001), while the genotype affected cooking time (P < 0.05), but not water absorption capacity. Significantly longer cooking time (75 minutes, P < 0.05) for red color seeds and shorter cooking time (62 minutes, P < 0.05) for white color seeds were found compared to the mean. The medium-seed-size genotypes had the shortest cooking time. Meanwhile, both the medium and large-seed-size genotypes exhibited high yields. Seven genotypes (NAROBEAN6, SMR48, SCR60, SCR45, SCN20, KND100, SCN744), which showed superior performance based on best linear unbiased predictor values for the traits studied, should be further tested across multiple climates and considered in common bean improvement programs. The phenotypic trait, 100-seed weight, is important particularly when breeding for yield and cooking time. This study uniquely highlights the common bean genotypes that might be critically important in drought-stress environments and for the improvement of food security in Uganda and Africa at large.