Effect of potassium sulfate on chlorophyll and drought toleranceindexin the Mungbean genotypes in the north of Khuzestan Province

In order to evaluate the effect of potassium sulfate nutrition on chlorophyll contentand drought tolerance indexon Mungbean genotypes in the north of Khuzestan Province, this study was conducted in split plot factorial in a randomized complete block design with three replications in 1390 and 1391 at the agricultural Research center south of west Country (Safiabad). The main plot was irrigation after 120, 180 and 240 mm evaporation from pan evaporation (respectively marked I120, I180 and I240),and the subplots were potassium fertilizers with 0, 37.5 and 75 kg K2O per hectarfrom potassium sulfate(respectively marked F0,F1 and F2) and genotypes (Parto, Hindi and VC6173, Cn95 and KPS1lines ) in a factorial arrangement.The results showed that grain yield in I180 and I240 treatments, reduced 21.8 and 30.4 percent respectively in comparison with control treatment(I120).the highest and lowest tolerance to drought stress were allocated to Hindi (0.83) and KPS1 (0.47) respectively. Potassium application at the rate of 75 kg/ha in I240 treatment, increased drought tolerance in all genotypes except KPS1. chlorophyllcontent was influenced irrigation regimes, irrigation and genotype, irrigation-fertilizer as well as the interaction of three factors at the of 1% and fertilizer and genotypes at the level of 5%.The overall results showed that Hindi due to high drought tolerance and VC6173 due to shoot standing and high drought tolerance were superior to other varities.