برهمکنش کم‌آبیاری و قطع ‌آب بر توزیع مجدد مواد ذخیره‌ای، فتوسنتز جاری و رابطه آن با عملکرد ذرت دانه‌ای

In order to evaluate the interaction of both treatments of deficit irrigation during growth duration and irrigation-cut in some growth stages, on reserve materials redistribution, current photosynthesis and its relation with yield of grain maize this research was conducted as factorial in randomized complete blocks design with three replications at research field of islamic azad university, sciences and research branch of khuzestan during 2007-2008 and 2008-2009 two cropping years. the research treatments were consisted of deficit irrigation at three levels (providing 100, 80, 60 percent of full irrigation requirement was measured for corn) and irrigation-cut at different growth stages at five levels (without irrigation-cut during growth duration (control), one time irrigation-cut at eight-leaf, twelve-leaf ,the pollination and milky stage). irrigation treatments applied at four to five leaf stages and continued until ten days before plant physiological maturity. the results of this research showed that the effect of deficit irrigation and irrigation-cut treatments on the amount, contribution and efficiency of current photosynthesis and redistribution was significant. with increasing intensifying deficit irrigation, current photosynthesis contribution decreased instead redistribution contribution in grain filling increased. in treatment of providing 100 percent plant irrigation requirement, the highest and lowest contribution of current photosynthesis belonged to treatments without irrigation-cut tension and lack of irrigation at flowering stage by the average of 81 and 41 percent, respectively.