effect of sodium nitroprusside application on leaf area, growth and water use efficiency of kidney bean under water deficit stress

in order to study of sodium nitroprusside(snp) application effect on growth indices and water use efficiency of kidney beans cultivars(akhtar and derakhshan) under water deficit stress, an experiment was conducted in split factorial based in randomized complete block design with three replications in bu-ali sina university research field at 2012. water stress treatments included vegetative stress, reproductive stress, vegetative+reproductive stress and non-water stress (control). foliar application of snp was done in 3 concentration(0, 150 and 300 µm snp). reproductive stress reduced leaf area, crop growth rate and total dry weight in both cultivars. snp foliar application (300 µm) increased mentioned indices 28, 26 and 20 percent in akhtar and 28, 20 and 20 percent in derakhshan in comparison to without foliar application, respectively. water use efficiency of grain and water use efficiency of biomass in vegetative stress was more than of non-water stress. maximum amount of water use efficiency was for akhtar cultivar with 300 µm sodium nitroprusside foliar application and were 0.72 and 2.9 percent for grain and biomass, respectively. snp foliar application ameliorated and improved negative effects of vegetative and reproductive stress. snp application(300 µm) had more effect on growth and yield in both cultivars at all water regimes. therefore, foliar snp(300 µm) it’s desirable for kidney bean under water deficit stress.