Influence of Irrigation Regimes at Different Growth Stages on Development and Yield in Maize (Zea mays L.)

THE MAIZE (Zea mays L.) was grown on a clay soil at Irrigation Development Area of Alwezaria, Kafr El-Shiekh, Egypt, during 2012 and 2013 seasons, to study the effect of irrigation regimes during different growth stages on growth, grain yield and water relations. Irrigation was applied at 50% (high level, H) and 65% (low level, L) depletion of available soil moisture (DAM) during different growth stages [vegetative stage (S-1) from the third leaf (V3) to onset tasseling (VT) stages, reproductive stage I (S-2) from VT to mid-milk (R3) stages, reproductive stage II (S-3) from mid R3 to physiological maturity (R6)]. I-HHH treatment (Irrigated at 50% DAM during three growth stages) or I-HHL (Irrigated with 65% DAM at S-3 stage only and 50% DAM was used during S-1 and S-2 growth stages), I-LHH (Irrigated with 65% DAM at S-1 growth stage only and 50% DAM was observed during S-2 and S-3 growth stages) and I-LHL (Irrigated with 50% DAM at S-2 growth stage only and 65% DAM was observed during S-1 and S-3 growth stages) resulted in significant increase in leaf area index (LAI) and dry weight/plant at 99 days after sowing (DAS), crop growth rate (CGR) at the period of 81-99 DAS, ear length, ear diameter, kernels number/ear, grain weight/ear, 100-grain weight and grain yield compared with I-LLL (Irrigated with 65% DAM during three growth stages) in the two seasons. There were no significant differences in grain yield among the irrigation treatments I-HHH, I-HHL, I-LHH and I-LHL in the mentioned traits in both seasons. Abundance soil moisture in root zone during S-2 stage (containing tasseling, silking, blister and mid-milk stages) is necessary to achieve high grain yield equal to that during entire season. I-HHH treatment recorded the highest values of applied water (7286 and 7321 m(3)/ha), while I-LLL recorded the lowest values 6171 and 6198 m3/ha in the two seasons. Although, the treatments received irrigation at 50% DAM during S-2 stage (I-HHL, I-LHH and I-LHL treatments) were equivalent to those received irrigation at 50% DAM during entire seasons (I-HHH treatment), they were lower in amount of applied irrigation water and water consumptive use. They saved at least 11.3, 16.0 and 19.9% applied water parallel with the yield decrease at the most 3.1, 3.2 and 5.3% than I-HHH treatment, respectively. Also, they increased the productivity of applied water (WPwater applied) and water consumptive use (WP (WCU)) (kg grain/m(3) water) compared with I-HHH in both seasons. At North Delta, Penman Monteith equation can be used in determining the actual consumptive use and the average of crop Coefficient (Kc) for the two seasons was found to be 0.43, 0.54, 0.64, 0.58 and 0.51 during emergence, vegetative, tasseling to milk, milk to dent and dent to maturity stages, respectively. Therefore, when irrigation water becomes a limited factor for agriculture, we can apply I-LHL treatment which resulted in high grain yield and water productivity equal to I-HHH with less amount of applied irrigation water and consumptive use in Kafr El-Shiekh Governorate.