Evaluating common bean lines for disease resistance and yield

Abstract

Plant disease resistance and seed yield are the result of many plant growth processes affecting the yield components of pods per plant, seeds per pod, and seed weight. The present study evaluated the common bean lines for disease resistance and yield. Field experiments were carried out in the CIAT Africa screen house based at Kawanda Agricultural Research Laboratories Institute (KARL), Uganda, for two main cropping seasons. A total of 36 common bean lines were evaluated for their disease resistance and yield performances for two seasons. The results showed that the majority (32) of the common bean lines in season 1 were resistant to Angular Leaf Spot in the field, unlike in season 2, where the majority (33) were moderately resistant, and in both seasons, no common bean line was susceptible to the Angular Leaf Spot in the field. The results also showed that in both seasons 1 and 2, most of the common bean lines were resistant to Anthracnose, Ascochyta blight, Rust, and Common Bacterial Blight on leaves in the field. However, season 2 had 12 common bean lines susceptible to Anthracnose on leaves. Both in seasons 1 and 2, most of the pods of all the common bean lines were resistant to Anthracnose, Rust, and Ascochyta blight in the field. In season 1, the pods of all common bean lines were resistant to Angular Leaf Spot and Common Bacterial Blight, while in season 2 majority were moderately resistant, and 7 common bean lines were susceptible to Common Bacterial Blight in the field. The average number of plants per effective area (PLPLOT) ranged from 43.0 to 6.5 plants per plot, with KDA17 common bean line having the highest and KDA44 having the lowest in season 1, while in season 2, it ranged between 60.0 and 16.5 plants per plot, with KDA17 having the highest and KDA8 having the lowest. The average number of plants per effective area for most of the common bean lines was generally higher in season 2 than in season 1, except for MEXICO54 and CAL96. From the present study, it can be concluded that the common bean lines were generally resistant to many of the diseases in season 1, while they indicated better growth and yield in season 2. The susceptibility of the common bean lines to diseases in both seasons was very low. I recommend that further studies should be conducted to prove the disease resistance of these common bean genotypes at various locations in Uganda.