The Effect of Irrigation Intervals Scheduling and Nitrogen and Zinc Content on Wheat Yield and Yield Components in Drought Stress

In order to evaluate the effect of irrigation interval on yield and quantitative-qualitative characteristics of bread wheat, splited plot experiment in randomized block with four replications in the 2010-11 crop years was conducted in the research field of Islamic Azad University of Gonabad. A number of 7, 9 and 10 days irrigation treatments formed the main factors of test, and spraying and non-spraying of nitrogen and zinc were considered as subfactor of test. The results showed that the effect of irrigation was significant for the number of grains per spike in the level of 5% and on 1000-grain weight and fat percent at the level of 1%, and had no significant effect on grain yield, biological yield, number of spikes/sq m stem height, stem diameter and protein content. Nitrogen treatment was significant at the level of 5% on biological yield and number of spikes/sq m, but had no significant effect on grain yield, number of grains per spike, 1000-grain weight, stem height, fat and protein percent, and stem diameter. Treatment with zinc was statistically significant in probability level of 1% only on percentage of fat and had no significant effect on grain yield, biological yield, grain numbers per spike, weight of 1000 seeds, spikes/sq m, stem height, protein percent and stem diameter. Seven days irrigation with of nitrogen allocated for highest seed yield (265.38 g/m²/sq m) and biological yield (659.33 g/m²/sq m). Means comparison showed the highest 1000-grain weight was obtained from 7 days irrigation (47.10 g) and the lowest from 13 days irrigation (40.44 g). According to the experiment results, 7 days irrigation was recognized as the best irrigation to achieve maximum economic performance and 13 days irrigation were determined as most appropriate irrigation for maximum performance for the region due to lack of water and weather conditions of Gonabad, spraying zinc and nitrogen to improve production was proposed depending on different irrigation and the purpose of production.