在杂交稻南优二号制种实践中我们常可看到,尽管两亲本花期相遇很好,但异交结实率不一定高,往往还有大量母本颍花不能受精结实,对制种产量的提高影响极大。其原因,我们通过三年的观察研究,认为除了与品种特性有关外,还与气象条件的影响有密切相关。从一九七六年晚造开始,我们以亲本花期相迂和亲本行比、株行距以及栽培技术措 In the practice of hybrid rice Nanyou 2, we often see that although the flowering of the parents is very good, the rate of outcrossing is not necessarily high, and there are often a large number of female flowers that can not be fertilized. The impact of the increase is enormous. The reason, we through three years of observational studies, that in addition to the characteristics of the species, but also with the impact of meteorological conditions are closely related. Since the late 1976 construction, we have adopted the principle of flowering parents and their parents, spacing and cultivation techniques