Scheduling Irrigation as a Water Saving Practice for Corn (Zea mays L.) production in Iraq

A field experiment was conducted by using a factorial randomized complete block design (RCBD) in three replicates with four irrigation intervals (7, 8, 10 and12 days), which equivalent to 14, 12, 10, and 8 irrigations for two seasons of 2012 and 2013. Irrigation water was applied to the spring var. 5018. The results showed that different irrigation intervals applied had statistically significant effect on number of days to male and female flowering, plant height, leaf area, root dry weight, biological weight and yield. The results in both full irrigations (7and 8 days) which was equivalent to 14, 12 irrigation respectively indicated that no significant difference (P<0.05) between these two treatments, although the maximum yield was obtained from full irrigation 7 days, but these treatments have significant difference (P<0.05) with deficit irrigation treatments (10and 12 days) which equivalent to 10and 8 irrigation in above plant traits and yield. The treatment of 8 days irrigation interval gave highest productivity of irrigation water 0.631 and 0.693 kg/m3 than other irrigation intervals of 7,10 and 12 days which were 0.604, 0.622, 0.552 and 0.587, 0.415 , 0.575 kg/m3in the two seasons respectively. The irrigation interval of 8 days saved about 14% of irrigation water per hectare comparing with other intervals. It can be concluded that the deficit irrigation can improve and increase the water productivity of corn associated with increased yield within an acceptable level under Iraq's semi-arid conditions.