Effects of Irrigation Rate and Frequency on Growth and Yield of Hybrid Cotton under Drip Irrigation

Field experiments were conducted to investigate the effects of irrigation rate and frequency on growth and nitrogen uptake of hybrid cotton under drip irrigation.Two irrigation rates were set as 400 and 520 mm and two irrigation frequencies were set as 5 and 10 d.Soil water content at 0-40 cm depth in highfrequency irrigation treatment(5 d) were higher than that in high-frequency irrigation treatment(10 d) under two irrigation rate levels.Dry matter accumulation of hybrid cotton was influenced by irrigation rate and frequency after flowering stage(day after planting 90 d).Total dry mass,yield and water use efficiency increased with irrigation rate and frequency increasing.The order of total dry mass,yield,and water use efficiency for different treatments followed as W520F5 W400F5,W520F10 W400F10.These results suggested that yield and water use efficiency of hybrid cotton can enhanced by increasing irrigation frequency under drip irrigation.