ElahehHasanzadeh, MehdiGhajar Sepanlou and Mohammad Ali Bahmanyar
In order to study the effect of potassium and manure fertilizer on yield and water use efficiency in wheat (N-81-18 cultivar) under drought stress, a pot experiment was conducted in split plot based on completely randomized design with four replications in 2009-2010 crop year. The main factor included irrigation after depletion of 75, 50 and 25 percent available plant water and the subsidiary factor was potassium in three levels (0, 300 and 600 kg/ha potassium sulfate fertilizer) and manure fertilizer in three levels (0, 20 and 40 ton/ha). Result indicated that irrigation treatment had significant effect on concentration of iron, zinc, copper and manganese in leaf and grain. The manure treatment had significant effect on concentration of iron, zinc, copper and manganese in grain at p<0.01 and on concentration of iron in leaf at p<0.05. Potassium treatment was significant (p<0.01) only on concentration of copper in leaf and grain. Interaction effect of irrigation and manure fertilizer treatments were significant on concentration of all micro element in leaf and grain and interaction effect of potassium and manure fertilizer was significant (p<0.05) only on concentration of iron. The most concentration of iron and manganese in leaf of wheat were observed in irrigation treatment after depletion of 75% of available plant water and maximum amount of zinc in irrigation treatment after depletion of 25% of available plant water and consumption of 20 tons of manure fertilizer ha-1. Also, maximum amount of copper in leaf of wheat was obtained in irrigation treatment after depletion of 25% of available plant water and consumption of 40 tons of manure fertilizer ha-1. Concentration of iron, manganese and copper in grain of wheat enriched to maximum in irrigation treatment after depletion of 50% of available plant water and consumption of 40 tons of manure fertilizer ha-1 and zinc of grain in irrigation treatment after depletion of 75% of available plant water without consumption of manure fertilizer.