“两杂”制种时双亲花期能否相遇,是杂交制种成败的关键。因此必须从父、母本出苗开始就经常不断地进行花期预测,以便及时采取促控措施,达到花期相遇的目的。1预测方法1.1察叶法。双亲自交系的总叶片数基本一致,可在制种田内选有代表性的点进行定株观察,一般每块地可选3￣5点, It is the key to the success or failure of hybrid seed production that the two parents have the chance to meet the flowering date during the seed production. Therefore, it is necessary to constantly forecast the flowering period from the beginning of the emergence of the parent and the female so as to promptly take the control measures to achieve the purpose of the flowering encounter. 1 prediction method 1.1 leaf inspection method. The total number of parents of inbred lines is basically the same, can choose the representative point in the system of farming for observation of plants, generally each optional 3 ~ 5 points,