The Effect of Water Stress on Grain Yield and Protein of Spotted Bean (Phaseolus Vulgaris L.), Cultivar Talash

In order to investigate drought stress and plant density the yield, yield components and protein of spotted bean grain (cultivar Talash), an experiment was carried out as split plots in randomized complete blocks with three replications in Yasouj, in 2012. Factors of the test including irrigation in three levels; without stress (control treatment), water stress in vegetative stage (interrupting the irrigation at the opening stage of the third to fourth true leaf), and water stress at reproductive stage (interrupting the irrigation at the stage of 50% flowering) as the main factors and four density level including 15, 25, 35 and 45 plants per m2 were considered as subfactors. The results showed that, the effect of water stress, plant density and interaction of water stress and plant density on grain yield, grains number in the pod, pods number in the plant and the weight of 100 grains was significant. The maximum yield was observed in the control plot and density of 45 plants per m2, also the minimum yield was observed in the reproductive stress treatment and density of 25 plants per m2 by 2398 and 1629 kg/ha respectively. Water stress treatment caused yield reduction at the stage of vegetative and reproductive growth by 10.4% and 32% respectively. The maximum amount of protein was obtained in the water stress treatment at the stage of reproductive growth. Considering the results of this experiment, the densities of 45 plants per m2 for normal irrigation conditions as well as 35 plants per m2 under water stress conditions are suggested