Effect of Sulfur and Zinc Fertilizers Application on Yield, and Yield Component of Corn (Zea mays L.) Under Different Irrigation Levels

In order to study the effect of zinc and sulphur fertilizers application on yield and yield component of corn under different irrigation levels an experiment was conducted in the experimental farm of agricultural faculty, university of Kurdistan in the growing season of 2010. The experiment was arranged in split-plot factorial based on a randomized complete block with four replications. Three irrigation levels consisted of full irrigation (-2 bar), moderate drought stress (-7 bar) and severe drought stress (-12 bar) that was considered as main plots. Two sulphur fertilizer levels included application of zero (control) and 30 kg/ha with two zinc fertilizer levels consisted of application of zero (control) and 1 kg/ha which were allocated to sub plots. The measured traits were: number of ears m-2, number of grain row per ear, number of grains per row, number of grains per ear, ear weight, weight of ear cob, grains weight per ear, seed thousand weight, grain yield, dry matter yield and harvest index of corn. Results showed that drought stress decreased amounts of all studied properties. The number of row per ear, number of grains per row, grain and dry matter yield characteristics were significantly affected by interaction of irrigation levels × sulphur fertilizer interaction. Interaction between zinc and sulphur fertilizers noticeably was significant on traits of number of grain row per ear and number of grains per row. The application of sulphur fertilizer under full-irrigation condition increased grain and dry matter yield and also reduced the effects of severe drought stress on corn yield. The zinc fertilizer application under well-irrigated condition caused to increase in amounts of some properties, but in the major studied traits had not any role in reducing the effect of drought stress.