调亏灌溉对棉花生长发育及其产量和品质的影响

Effect of Regulated Deficit Irrigation on Growth and Development Characteristics in Cotton and Its Yield and Fiber Quality

在移动式防雨棚下，采用子母盆栽土培法，以美棉99B为试验材料进行调亏灌溉（Regulated Deficit Irrigation，缩写RDI）试验研究，旨在了解RDI对作物不同生育阶段生长发育特性、经济产量（Y）和水分利用效率（WUE）以及经济产品品质的影响，寻求适宜的调亏生育阶段（时期）和调节亏水度，为建立棉花RDI指标与模式提供理论依据。试验采用二因素（水分调亏阶段和调节亏水度）随机区组设计。结果表明，适时适度的水分调亏具有根系下扎的诱导效应，抑制植株营养体冗余生长，促进生殖生长，有利于光合产物向子棉运转与分配，提高经济产量；能够改善部分品质指标。棉花RDI的适宜指标是：苗期轻、中度调亏，0～40cm土层湿度控制下限为田间持水量的60％FC（Field capacity）或50％FC；蕾期轻度调亏，0～40cm土层湿度控制下限为60％FC；花铃期不宜调亏，应保证充足供水，0～40cm土层湿度应不低于75％FC；吐絮期可中度调亏，0～40cm土层湿度可控制在50％～55％FC。

Under the condition of mobile rain-proof shelter, by cultivating in pots filled with soil, with cotton （Gossypium hirsutum cv. 99B） as material, the experiment in Regulated Deficit Irrigation （RDI）, aimed at investigating the effects of RDI on growth and development dynamic of plants, unginned cotton yield and fiber quality, was conducted during the growing season from 2004 to 2006, seeking for the right stages of RDI and the amount of water deficit, offering theoretical basis for the establishment of RDI model in cotton. A twofactor （RDI stages and the amount of water deficit）randomized-block design was adopted in cultivating in pots. The results showed that there was an inducing effect of RDI on amount of roots of cotton distributed in deeper layer of soil. RDI was able to inhibit the excess vegetative growth and promote reproductive growth of cotton. Under appropriate amount of water deficit at some growing stages, the proportion of photosynthetic products distributed in the unginned cotton tended to increase, unginned yield was increased and some of fiber quality indices were improved. The suitable indices of RDI for water-saving and high-yield in cotton as fol lows： the optimum stage of regulated water deficit is seedling stage, the amount of water deficit is 50%FC （Field Capacity）～60%FC, or regulated water deficit at budding stage, the amount of water deficit is 60% FC, or regulated water deficit at boll-opening stage, the amount of water deficit is 50%FC～55%FC.