Effect of arboscular mycorrhiza on water use efficiency and grain yield of mungbean under water Stress conditions

In order to evaluate the effects of mycorrhizal fungi and different irrigation regimes on water use efficiency (WUE) and zone profit on mungbean NM92, an experiment was conducted under field conditions at two seasons of 2009-10. A split plot experiment was based on Randomized Complete Blocks Design with three replications carried out at research field of Urmia University. Four levels of irrigation (50, 100, 150 and 200 mm evaporation from class A pan) and mycorrhiza species (Glomus mosseae, Glomus intraradices and non-inoculation) were arranged at main and sub plots, respectively. Combined analysis of variance showed that the effect of mycorrhiza and water stress on all traits; root colonization, grain yield, leaf nitrogen and phosphorus, water use efficiency, net profit and zone profit were significant differences (P≤0.01). Also, interaction between water stress and mycorrhiza showed significant differences(P≤0.01) on colonization percentage. With increasing water stress, colonization percentage was the most in G. intraradices compared with G. mosseae. The highest and lowest grain yield obtained from 50 and 200 mm evaporation with 1833.51 and 1139.56 kg/ha. In mycorrhiza treatments,maximum and minimum grain yield obtained in G. intraradices andnon-inoculation with 1612.72 and 1307.92 kg/ha. Although, water stress decreased grain yield, but two species of mycorrhiza strongly reduced its effect. Mycorrhiza with increasing of nitrogen, phosphorus and water use efficiency caused high grain yield under well watered and water stress. With reducing of water consumption decreased WUE; hence maximum (0.60 kg/m3) and minimum (0.32 kg/m3) WUE obtained from 200 and 50 mm evaporation from pan. G. intraradices had the highest (0.49 kg/m3) WUE. With reducing of water consumption decreased net profits, but zone profit increased due to use of water saving. Therefore, for increasing grain yield is recommended the use of G. intraradices as a biological fertilizer.