improving tolerance to water deficit using zn foliar spraying in two common bean cultivars

in order to investigate the impact of foliar zn application in reducing the negative effects of water stress on bean growth and yield, a field experiment was carried out in the research field of ilam university in 2011. the experiment was arranged in split factorial based on a randomized complete block design with three replications. the experimental factors were water stress including water withholding at flowering, water withholding at pod formation and control (full irrigation) as main plot, and the factorial of zn application levels including; 0, 2000 and 4000 ppm and two bean cultivars including; akhtar and dorsa as sub-plots. results showed that water stress significantly reduced grain yield and the lowest grain yield obtained from water stress at flowering stage. the highest (3163.6 kg/ha) grain yield achieved by zn application with 4000 ppm concentration. there was a significant difference between cultivars in different treatments and in overall dorsa with 3846.4 kg/ha produced the highest grain yield. according to the results the most sensitive stage of bean plants to water stress is flowering stage and zn application with a concentration of at least 4000 ppm can improve plant tolerance to water deficit.