Effect of tillage and moisture levels on growth, yield and nodulation of common bean (Phaseolus vulgaris) and mungbean (Phaseolus radiatus) in the dry season

Abstract

A field experiment was conducted at the Experimental farm of the University of Peradeniya, Sri Lanka, over 2 dry seasons (May-August 1999 and 2000) to evaluate the impact of tillage and soil moisture on growth, yield and nodulation of common bean (Phaseolus vulgaris L.) and mungbean (Phaseolus radiatus L). The legumes were grown in tilled or compacted soils, under rainfed or irrigated conditions, which corresponded to low or high soil- moisture regimes. Germination of the small-seeded mungbean was reduced by soil compaction and low moisture. Crop growth of mungbean was also reduced to a greater extent by soil compaction and moisture stress. In contrast, the adverse impact of soil compaction and moisture stress was greater on pod yields of com- mon bean than on seed yields of mungbean. Tillage promoted root branching to a greater extent than root dry weights of both species, especially in the low soil-moisture regime. Nodulation was reduced to a greater extent by soil-moisture stress especially in common bean, the poor nodulating species.