Responses of Popcorn to Irrigation Rates and Timing of Irrigation Termination

Abstract

Irrigation rates and timing of irrigation termination in relation to crop maturity directly affect yield and costs of popcorn production. Responses of a popcorn variety to 3 irrigation rates (the ratios of irrigation water to evaporation, IW/E 0.5 , 0.7 and 0.9) and 4 irrigation termination (R1 , R3, R4 nd R6) were examined on a clay soil at Chai Nat field Crop Research Centre. The number of irrigation throughout the growing season was between 4-8 with irrigation amounts of 108-315 mm, depending up on irrigation rates and timing of the last irrigation. The responses in growth and yeild o firrigation rates to irrigation termination were similar. Leaf area gave an average yield of 637 kg/rai, which was 6.4 and 17.0% higher than IW/E 0.7 and 0.5, respectively. Irrigation terminated at R4 and r6 stages showed no significant differences in yields, whereas irrigation terminated at R3 and R1 reduced yields up to 7.3 and 17.6% , respectively, compared to R6 termination. reduction in the number of ears harvested, and grain size was the main factors causing lower yields of lower irrigation rates and early irrigation termination.