近年来,由于推广了加大密度、改进了行比等技术措施,玉米制种的产量有了较大幅度的提高。但由于在播期上掌握不好,产量仍不稳定。例如: 1.1981年,我县白池村白单4号制种基地上出现了以下三种情况:4队段增录于4月15日播种3亩,由于伏天大旱,造成颗粒无收;而于5月20日播种的相邻地块,亩产达150多公斤;同年,8队于6月14—18日播种的30亩,每亩只收了50余公斤,因未成熟,不能作种。 In recent years, due to the promotion of increased density and improved technical ratios, production of maize seeds has been greatly increased. However, due to poor grasp of the sowing date, the output is still not stable. For example: 1. In 1981, the following three situations occurred on the seed production base of Baidan No.4 in Baicun Village in our county: In the 4th stage, 3 acres were sown on April 15, In the adjacent plots sown on the 20th, the yield per mu reached more than 150 kilograms. In the same year, the 8 units of 30 mu sown on June 14-18 received only 50 kilograms per mu. Because of immature, they can not be planted.