Effect of Limited Irrigation on Yield and Yield Component of Several Sweet Corn (Zea mays L.var Saccharata) Varieties

A randomized complete block design with four replications and a split plot arrangement was conducted in 2010، in order to study the effect of limited irrigation on yield and yield component of sweet corn. Water levels were (100%، 80%، and 60% replacement of plant water requirement) which served as main plots. Subplot was a factorial arrangement of three different sweet corn varieties (Merit، Obsession and KSC403) with two planting methods (raised bed and furrow planting). The evaluated traits were ear length، ear diameter، kernels number per row، seed rows per ear، kernel depth، seed thousands weight، kernel yield، shoot biomass، harvest index and Anthesis- silking interval. Results show that limited irrigation significantly decreased all measured characteristics but harvest index. Effect of varieties was significant on evaluated traits too. Kernel weight and seed depth were significantly affected by interaction between variety and planting method. The highest yield was found for 100% replacement of water requirement irrigation level whit 15. 2 tones per hectare kernel weight and the lowest belongs to 60% replacement of water requirement by 8. 6 tones per hectare kernel weight. Merit and KSC 403 produces the highest (15. 9 ton/ha) and lowest (8. 8 ton/ha) seed yield، respectively. Harvest index of different varieties were not affected by irrigation regime. Results show that، in whole، limited irrigation، decreased seed yield in all varieties by affecting diverse yield component.