Effects of mycorrhizal arboscular on grain yield and yield component of Mungbean [Vigna radiate (L.) Wilczk] under water deficit stress

Deficit irrigation is an effective method for alleviation of drought impacts and water usage reducing in drought period. Deficit (or regulated deficit) irrigation is one way to improve efficiency of water usage that crop is exposed to a certain level of water stress during a particular period.Therefore, in order to investigate the effect of deficit irrigation on yield and its attribute and water use efficiency of cotton under the terms of tape irrigation systems, a field experiment was carried out during 2010 growing season at experimental farm of Orzoueyeh Agriculture and Natural Resources Research Center in Kerman province. The treatments were laid out in split plot a Randomized Complete Block Design (RCBD) design with three replications. The treatments were comprised of three levels of irrigation including 100 (control), 80, 60 percent of crop water requirement in main plot and two irrigation systems as sub plot consisted of surface drip irrigation system (S1), subsurface drip irrigation system (S2). The results showed that In comparison with 100 percent of crop water requirement, 80 percent of water requirement caused parsimony of water usage equal 1500 m3 ha-1, and yield, number of bolls per plant and bolls weight decreased 12%, 11% and 2.5% respectively, but WUE was increased 5%. Also 60% of water requirement treatment compared with 100 % of water requirement caused parsimony of water usage equal 3200 m3 ha-1, and yield loss, number of bolls per plant and bolls weight decreased 38%, 37% and 24% respectively. The WUE amount is the same as it. Considering the results obtained in this study in the light of water saving as the main object in deficit irrigation and water use efficiency (WUE) for cotton cultivation in Orzoueyeh, the 80% of crop water requirement is preferred.