Effect of water stress and foliar micronutrient application on physiological cahracteristics and nutrient uptake in mung bean

In order to study the effect of Mn and Zn micronutrients foliar application on quality and quantity characteristics of mung bean under water stress a field experiment was conducted at the University of Zabol in 2011-2012. The experiment was conducted in split plot design with three replications. Main plots were different levels of drought stress included: optimum irrigation, withholding irrigation in vegetative growth stage, and with holding irrigation in flowering stage. Sub plots were of four levels of micronutrients foliar application included: no foliar application, 3000 ppm foliar application of zinc, 3000 ppm foliar application of manganese, and foliar application of zinc+manganese. The results showed that the highest plant height, No. capsule in plant, No. seed in capsule, 1000 seeds-weight and biological yield and harvest index obtained from optimum irrigation treatment. The highest grain yield was achieved from optimum irrigation treatment and foliar application of zinc+manganese. The most amounts of carbohydrate percentage, zinc and manganese was achieved from treatments of micronutrients foliar application. But micronutrients application led to decreasing phosphorous uptake in plant. The results showed that interaction between irrigation treatments and micronutrients foliar significantly increased plant height, grain yield and biological yield. The highest grain yield (451 Kg ha-1) was achieved from optimum irrigation and foliar application of zinc+manganese. It can be concluded that water stress at the flowering stage had the most effect on reducing grain yield of mung bean. Although the highest concentrations of carbohydrates and proteine were found in water stress at the vegetative growth stage, Since reduction during seeds filling period and the lack of adequate absorption of micronutrients, the effects of the drought in was more pronounced at the vegetative growth stage than water stress the flowering stage, and drought stress in this stage decreased grain yield.