Variation Trend of Leaf Area Index, Yield and Yield Components of Green Beans (Phaseolous vulgaris L.) by Using Zinc Sulfate and Nitrogen

Proper nutrition of plant is one of the most important factors to improve both quality and quantiy of crop yields. Accordingly, the effect of different levels of zinc and nitrogen on leaf area index, yield and yield components of green beans investigated in the summer of 2012. The experiment used was a split plot in randomized complete block design with three replications in the Dezful. In this study, the main plots consisted of four nitrogen rates of urea (0, 30, 60 and 90 kgha-1), and sub plots of four levels of zinc sulfate (0, 10, 20 and 30 kg.ha-1). The results showed that application of 90 N kg.ha-1 increased leaf area index, plant dry matter, grain yield, biological yield, harvest index and protein content. Use of zinc sulfate at the rate of 20 kg.ha-1 was superior in grain yield and yield components. The highest leaf area index, grain and biological yields harvest index and protein content were achieved by application of 90 kg nitrogen and 20 kg of zinc sulfate per hectare. It seems that the use of zinc with appropriate rates, through its involvement in physiological processes and nitrogen metabolism in plants as an essential element, accelerates green beans growth processes and increases green bean yield.