就我国广大棉区而言，棉花的花朵一般都在上午 7～ 10时开放、授粉。花粉落到柱头上不久就可萌发伸出花粉管，花粉管沿着棉花花柱经 8～ 12 h就可到达子房，从授粉到受精需 24 h以上。在花粉受精过程中，如遇到雨水冲刷或喷洒药液，不但冲散花粉，使花粉破裂，丧失生活能力，而 In terms of the vast cotton area in our country, the flowers of cotton are generally open at 7-10 am and pollination. Shortly after the pollen fell to the stigma, the pollen tube could sprout out of the stigma. The pollen tube reached the ovary along the cotton style after 8 to 12 hours. From pollination to fertilization required 24 h or more. In the pollen fertilization process, such as in the event of rain or spray liquid spray, not only break the pollen, pollen rupture, loss of ability to live, and