Effect of Limited Irrigation on Growth and Yield of Bean Cultivars

A field experiment was conducted in 2008, to investigate the effects of different irrigation treatments (I1,I2,I3 and I4: well-watering on the bases of 70mm evaporation from class A pan and irrigation disruptions at flowering stage, grain filling stage and during flowering and grain filling stages, respectively) on growth and yield of three pinto bean cultivars (Talash, Khomain and COS16). The experiment was arranged as split-plot based on randomized complete block design in 3 replications, with the irrigation treatments in main plots and pinto bean cultivars in sub-plots. Dry matter accumulation, crop growth rate, relative growth rate and grain yield per unit area decreased, due to water stress at reproductive stages. The percentage of grain yield reduction under irrigation disruption during flowering and grain filling stages compared to well-watering condition was about 40.25%. The most reduction was happened at water disruption during flowering and grain filling stages. Dry matter accumulation and crop growth rate of Talash was higher than for Khomain and COS16. Grain yield of khomain was slightly higher than that of other pinto bean cultivars. However, this difference was not statistically significant.