Effect of Water Deficit on the Growth and Water Production Benefit of Cotton in Planting Pattern of Cotton Intercropping with Melon

Abstract：The cropping pattern of cotton intercropping with melon which was cultivated relatively large area In Huanghuai region was taken as a research object,and the effects of water stress at different growth stages on growth,yield and water production efficiency of cotton were conducted to determine the suitable control indicators of soil moisture for cotton intercropping with melon.The results showed that proper water deficit at the seedling stage did not affect the growth and yields of cotton and melon significantly,but had a better effect of saving water.Water deficit at the square stage influenced cotton growth a little and got the best water saving effect,but had the most impact on the melon yield.As water deficit occurred during the early blossoming and boll forming stage,the number of bolls was less,boll shedding rate was high,as well as cotton and melon had a great reduction in yield,so the early blossoming and boll forming stage should be the key water demand period for both crop.Water deficit at the late blossoming and boll forming stage also resulted in boll shedding rate increase and blocked crop yield raise.Based on a comprehensive comparison of all indexes,the lower limit indexes of soil moisture for the high-yield and efficient of cotton intercropping with melon were proposed that soil moisture should not be less than 50% of field capacity at the seedling stage,and should be 60%~65%,75%~80% and 70%~75% of field capacity at the square stage,early blossoming and boll forming stage,late blossoming and boll forming stage,respectively.