干旱胁迫对南疆膜下滴灌棉田光合产物累积的影响

为明确适度干旱胁迫对新疆南部极端干旱区滴灌棉花生长及水分利用效率的影响。在常规滴灌(灌水量为4 650 m~3·hm~(-2))的基础上,设计4种减量滴灌模式(灌水量分别2 250、2 850、3 450和4 050m~3·hm~(-2)),分析不同滴灌量对棉花光合产物积累动态及产量形成的影响。结果表明,随着滴灌量的减少,蕾铃数比常规灌水量减少;蕾铃脱落率先减少后增加;根冠比呈现先增大后减小的趋势,在始花期滴灌量3 450m~3·hm~(-2)的根冠比大于常规滴灌处理;随灌溉量减少,干物质呈现先增加后减少的趋势,灌溉量为2 250~4 050m~3·hm~(-2)时干物质显著增加,常规灌水量下干物质量则呈下降趋势。随着灌水量的减少,单铃质量、单株结铃数也随着减小,从而阻碍棉花经济产量的提高。

Effect of Plastic Film on Evapotranspiration and Evaporation of Cottons under Drip Irrigation in Southern Xinjiang

This experiment is to determine the influence of moderate drought stress on the growth and water use efficiency of drip-irrigated cotton in extremely dry areas in South Xinjiang . With reference to the conventional drip irrigation (with irrigation amount of 4 650 m·hm^-2), four reduced-amount drip irrigation modles were designed (with irrigation volumes 2 250, 2 850, 3 450 and 4 050 m·hm^-2 respectively) to study the effect of varied drip irrigation amount on dynamics of photosynthetic mass accumulation and cotton yield. The results showed that,the number of buds and bolls reduced with the dwindling amount of drip irrigation compared with conventional irrigation, while bud and boll drop first decreased and then increased. Meanwhile, shoot ratio was in the trend of increase and then decrease at the early flowering stage, shoot ratio exceeded conventional drip irrigation when the amount of irrigation was 3 450 m·hm^-2. With reduced irrigation, dry matter increased at first , and then decreased. When the amount of irrigation was set at the range of 2 250-4 050 m·hm^-2, there was a significant increase in dry matter. Under conventional irrigation, the amount of dry matter tended to decrease with reduction of irrigation amount. The decrease of irrigation amount took its toll on individual boll mass and boll number on individual plants, and it limited the improvement of economic cotton yield.