effect of water deficit stress on some vegetative aspects and yield of cotton genotypes

in order to study of water deficit effects on yield and some vegetative aspects of cotton, 30 cotton genotypes evaluated in 2014 summer at garmsar agricultural research station in greenhouse and field conditions. the experimental design was split plot based on a completely randomized blocks with three replications. six superior genotypes including k8801, k8802, avengard, varamin, khordad and qum red boll selected for field experiment. main plot was stress levels including control, mild and sever water deficit and subplots designated to genotypes. in greenhouse, the results showed that vegetative indices of genotypes significantly affected by water deficit stress. based on the result of field experiment, vegetative traits, yield and yield components of genotypes were significantly different. in general, traits such as dry matter of root and shoot, number of root branches, crown diameter and chlorophyll content (spad value) had positive and significant correlation with yield in filed, so could be used in evaluation of cotton drought tolerance. also, k8801 had higher yield than other genotypes in water deficit condition and could be introduced as a superior genotype for the region of study.