Effect of nitrogen and phosphorus application on biomass and harvest index of mungbean (Vigna radiata L. Wilczek)

Nitrogen and phosphorus are essential nutrients in crop production. In order to investigate the effects of different nitrogen and phosphorus levels on biomass and harvest index of mungbean, Partow variety a field experiment was conducted at the Research Farm of the Islamic Azad University of Shahre-rey in Tehran, Iran in 2009. The Experiment was laid out with factorial arrangement in a Randomized Complete Block Design with three replications. Five levels of nitrogen (0, 30, 60, 90 and 120 kg N ha-1) and six levels of phosphorus (0, 30, 60, 90, 120 and 150 kg P2O5 ha-1) were the treatment variables. Results showed that application of N and P fertilizers significantly increased the biomass and harvest index. Interaction effect of nitrogen and phosphorus was significant. With the increase of phosphorus application, nitrogen had positive effect on increase of biomass and harvest index. The maximum biomass (793.8 g m-2) was obtained when 120 kg N ha-1 and 150 kg P2O5 ha-1 were applied. The highest harvest index (28.62%) was recorded when 90 kg N ha-1 and 120 kg P2o5 ha-1 were applied.