بررسی تاثیر مقدار آبیاری و تاریخ برداشت بر صفات زراعی در ذرت میان رس

To study the effect of irrigation amount and harvesting date on yield and yield components of two Medium-maturity Corn cultivars, an experiment was carried out as split- split plot, using randomized complete block design (RCBD) with three replications at Khorramabad Zone in 2005 cropping season. The experimental factors were irrigation amount at two levels (complete irrigation =control, irrigation sress at stages of 6 until 8-leaf) as main plot, two cultivars(540 single cross hybrid and 647 three way cross hybrid) as sub-plots, and three harvesting dates(20 days before and after physiological maturity, physiological maturity time) as sub-sub plots.The results showed that effect of low irrigation amount on the number of row per ear, the number of grain per ear and ear diameter , grain yield were significant at 5% probability level and the effect of harvesting time was significant on ear diameter and grain yield at 1% probability level.The interaction of irrigation stress and harvesting time was significant on grain yield at 5% probability level. Mean compirson according to Duncan test showed that there were significant difference among among treatments for mentioned traits. The highest grain yield (10060 kg/ha) was obtained from treatment of complete irrigation (control) ×540 cultivar ×harvesting at physiological maturity time, and the lowest grain yield (2830 kg/ha) was obtained from treatment of irrigation stress ×540 cultivar ×harvesting at time of 20 days before physiological maturity time. Also, correlation analysis showed that traits of the number of row per ear, the number of grain per ear had positive and significantly correlation with grain yield.