Effect of Skipping Irrigation in Different Phenological Periods on Yield and Some Physiological Parameters of Corn (Zea mays L.)

This study was carried out in Southeastern Anatolia Region in Turkey between 2017 and 2018 to determine the effect of irrigation skipping in different phenological periods on yield and some physiological properties of corn (Zea mays L.) in second crop conditions. The trial is designed as randomized complete block design with three replications. DKC-6664 hybrid corn variety having classified as moderate maturity in the FAO (650-700) maturity classes were used in the study. Four irrigation skipping periods which are full irrigation treatments (S1, control), irrigation skipping in vegetative growth period (S2), irrigation skipping in pollination period (S3), and irrigation skipping in generative development period (S4) were studied in the research. According to the two-year averages; there were statistically significant differences in hybrid corn variety in terms of investigated characteristics. According to results, grain yield (GY), chlorophyll content (CC, spad), water use efficiency (WUE, mm), crop water stress index (CWSI) and plant water consumption (ETa, mm) were ranged from 12761.5 (S2)-14021.3 (S1) kg ha-1, 39.10 (S4)-44.50 (S1) spad, 1.902 (S1)-2.114 (S3) mm, 0.18 (S3)-0.33 (S4) and 6752 (S3)-7712.0 (S1) mm respectively. Because of drier weather conditions in 2017 compared to 2018, while GY, CC, and WUE parameters decreased, CWSI and ETa parameters increased. In the first year of the trial when dry weather conditions prevailed, the corn variety consumed more water and was more stressed. As a result, yield losses were experienced. There were positive and significant correlations between GY and CC and WUE, and negative and significant correlations between CWSI. The results of the study indicated that irrigation should not be skipped during the entire vegetative period for economical and profitable corn production in semi-arid regions.