Effect of Nitrogen Fixation on Yield and some Yield Component of Common Bean (Phaseolus vulgaris L.) Genotypes under Moisture Stress

Abstract

Moisture stress is a worldwide production constraint for common beans and biological nitrogen fixation. The effect of drought has been widely reported and is an important environmental factor resulting in crop yield losses. This study aims at assessing the effect of nitrogen fixation on yield and some yield component of common bean (Phaseolus vulgaris L.) genotypes under moisture stress levels. Experiments were carried out in screen house and field at Sokoine University of Agriculture. The genotypes used were Kijivu, Yellow, Msolini, Masusu, Kasukanywele, Uyole 04, Mbulamtwe, Bilfa-Uyole and G 51495 A, a non-nodulating genotypes as a check. The soil moisture was maintained at 100, 75, 50 or 25% of the soil’s field capacity. Moisture stress reduced yield up to 67%. Genotypes Yellow (2.9 and 11.2g/palnt), Msolini (3.3 and 10.7g/plant), Masusu (3.6 and 7.7g/plant) and Bilfa Uyole (4.1 and 7.2g/plant) were observed to have some degree of drought tolerance based on its response under moisture stress environments for yield. These results suggest that moisture stress has a substantial impact on the general performance of common bean genotypes. Selection of superior performing genotypes under moisture stress, and integrating them into the breeding programs is an important to increase crop productivity.

Keywords; N₂-fixation; Drought; Nodulation; Legumes