Yield and water use efficiency of rice (Oryza sativa L.) relative to scheduling of irrigations

Irrigation scheduled at seven days’ interval during vegetative stage and four days’ interval during reproductive stage resulted in significantly higher panicle number and panicle weight, filled grains panicle-1 and grain yield. Permanent irrigation and interval irrigation methods had higher yield in comparison with saturated irrigation method in rice. Dry seeded rice significantly increased the water productivity with respect to irrigation water over wet seeded and transplanted rice. Intermittent irrigation in rice cultivation may reduce irrigation water use considerably (27-37%) compared with flooded rice cultivation. aerobic rice significantly required less water (67.91 ha-1 cm) to produce higher or on par yield as compared to transplanted puddled rice (122.59 ha-1 cm). Similarly, WUE was significantly higher in aerobic rice (81.31 kg ha-1 cm) as compared to transplanted rice (36.12 kg ha-1 cm). The irrigation schedule having three days’ drainage period after disappearance of ponded water yielded rice higher with maximum water use efficiency compared to continuous submergence or submergence at critical stages such as tillering, panicle initiation, flowering and milk, followed by saturation or field capacity between intermittent periods.