Elucidating the Effect of Genotype x Environment Interaction and Storage Period on Cooking Time of Selected Common Bean (Phaseolus vulgaris L.) Genotypes

The cooking time of Common beans (Phaseolus vulgaris L.) is among the important consumer’s preferred traits. Slow-cooking beans lose some important micronutrients (Fe and Zn) because prolonged cooking degrades the beans at a cellular level. Fast-cooking beans save fuel energy and time which could have been spent on slow-cooking beans. Storage conditions, seed composition, cooking method, and growing environment also have an effect on the cooking time of common beans. Thirty bean genotypes with checks (Rojo and SUA-90) were laid in a Randomized Complete Block design in three environments (Ndole, Kasanga, and Mlali) in the Morogoro region. After harvesting cooking time determination was held using an automated Mattson Cooker soon after harvesting and repeated after three months (90 days). Analysis of variance revealed a significant variation (P < 0.001) among genotypes and across the environments for the first and second cooking tests. In a combined analysis, cooking time unveiled a continuous distribution ranging from 72.3-121.2 minutes for the first cooking test and 104.8-215.1 minutes for the second cooking test. Selian 10 and KT-002 recorded the shortest cooking time in the first and second cooking tests while TARI-06 and NUA-746 recorded the longest cooking time. The GGE biplot revealed SUA-90, Selian 10, NUA-672, and KT-002 were the most stable and fast-cooking genotypes in the first cooking test while NUA-746, TARI-06, and ADP-190 maintained stability but took a long time to cook. In the second cooking test, Selian 10, Uyole-04, and Selian 97 revealed high stability with a short cooking time while TARI-06 and NUA-746 revealed high stability with a long cooking time. These findings suggest that some bean genotypes can maintain the stability of fast cooking traits even after being stored for a certain time, hence these candidates can be used for breeding purposes or released as varieties.