Effect of water stress at different growth stages on yield and yield components of Kidney bean cultivars

Investigation on the effect of water stress on crop yield is very important in Iran duo to arid and semiarid climates and limited water resources. In this research, a field experiment was conducted in research station of Zanjan University as split plot based on randomized complete block design (RCBD) with three replications. Water stress application at different growth stages including: vegetative (V), flowering (F), poding (P) stages were considered as main factor and kidney bean cultivars of Sayad, Akhtar, Derakhshan, Naz and D- 808 were placed in subplots. Irrigation index was decreasing 50 mm from evaporation pan (class A) and addition 50 mm for each water stress treatments. Measured traits were number of grains per pod, number of pods per plant, length of pod, 00 kernel weight, grain yield, biological yield and harvest index. Analysis of variance showed that there was significant differences between cultivars, stage of water stress application and their interaction in grain and biological yield of common bean. Results revealed that Sayad had better performance than other cultivars and high sensitivity of cultivars was observed to water stress at flowering stage. The greatest biological and grain yield was observed in Sayad cultivar in control (non stress treatment) and Naz in V treatment. The lowest value of the mentioned parameaters were observed in Akhtar cultivar in F treatment. In addition, Sayad had higher harvest index in control. Number of pods per plant and grain per pod were significantly reduced in F treatment and 00 kernel weight in treatment P. Among cultivars, Sayad produced more pods per plant and grain per pod, and Akhtar showed the highest 00 kernel weight. Grain yield showed significant positive correlations with harvest index and biological yield, but it had negative relationship with 00 kernel weight and number of pods.