棉花调亏灌溉的生态生理效应

在人工控制试验条件下 ,采用子母盆栽土培法 ,以棉花为试验材料进行了调亏灌溉试验研究。结果表明 ,棉花调亏灌溉是可行的 ,可以实现节水、高产和高效的目标。适时适度的水分调亏显著抑制蒸腾速率 ,而光合速率下降不明显 ,复水后光合速率又具有超补偿效应 ,光合产物具有超补偿积累 ,且有利于向棉铃运转与分配 ;抑制营养生长 ,促进生殖生长。棉花调亏灌溉的适宜指标是 :苗期轻、中度调亏 ,0～ 40 cm土层湿度控制下限为田间持水量的6 0 %或 5 0 %;蕾期轻度调亏 ,0～ 40 cm土层湿度控制下限为 6 0 %;花铃期不宜调亏 ,应保证充足供水 ,0～ 40 cm土层湿度应不低于 75 %;吐絮期可中度调亏 ,0～ 40 cm土层湿度可控制在 5 0 %～ 5 5 %。

Ecological and Physiological Effects of Regulated Deficit Irrigation in Cotton

A pot-cultivating experiment was carried out to study ecological and physiological effects of regulated deficit irrigation (RDI) in Cotton. Results showed that RDI was a practicable measure for water-saving, high-yield and high-efficiency in cotton. With appropriate level of water deficit at right growing stages, transpiration rate may be reduced obviously, but photosynthesis rate diminution was not obvious. There were super-compensation effects in photosynthesis and photosynthetic product accumulation from re-watering after controlled water deficit treatment. The proportion of photosynthetic products distributed to boll trended to increase. Vegetative growth was controlled and reproductive growth was promoted remarkably under RDI. The suitable indexes of RDI for water-saving and high-yield in cotton were as followings: seedling stage, bud stage and boll-opening stage are suitable for conducting RDI. The suitable controlling levels of water deficit are 50%θ F~60%θ F , 60%θ F and 50%θ F ~55%θ F for seedling stage, bud stage and boll-opening stage respectively.