由于杂交水稻父母本生育期相差较长,加之我省各地气候差异较大,所以杂交水稻制种时花期不遇是一个很辣手的问题。怎样才能使父母本花期相遇呢?实践证明,正确安排父母本的播种差期是非常重要的一环。确定父母本播种差期的方法很多,利用父母本从播种到始穗的有效积温差来确定是其中重要的一种。这种方法的进行步骤是: 首先通过分期播种实验确定父母本在当地自然条件下从播种到始穗所需要的最低温 Because hybrid rice parental growth period of a long difference, combined with large climatic differences across the province, so when the hybrid rice seed flowering is not a very hot question. How to make the parents meet the flowering it? Practice has proved that the proper arrangements for the poor sowing of parents is a very important part. There are many ways to determine the poor sowing date of the parents, and it is an important one to use the difference between the effective accumulated temperature difference of the sowing date and the starting date of the parents. The steps of this method are as follows: first, the staging experiment is used to determine the minimum temperature that the parents need from planting to starting spike under the local natural conditions