1.选择最佳抽穗扬花期,创造适宜的授粉环境。制种成败及产量的高低很大程度上取决于抽穗扬花期的气候条件。扬花期间连阴雨,温度过高或过低,对父本的供粉和母本授粉及异交性能有很大负作用,从而大幅度降低异交结实率。而晴天,无高低温危害,日照时数长则有利于授粉。据本地基地资料,1990 1. Select the best heading and flowering, to create a suitable pollination environment. The success or failure of seed production depends largely on the climatic conditions at heading and flowering. During the flowering period, even the rainy days, the temperature is too high or too low, has a great negative effect on the male parent’s pollination and female pollination and outcrossing performance, thus greatly reducing the outcrossing rate. And sunny, no high temperature damage, long hours of sunshine is conducive to pollination. According to local base information, 1990