我省北部棉区无霜期较短，生育期偏紧，部分棉田常因管理措施跟不上而贪青晚熟，形成大量霜后花，严重影响了产量和品质。据调查：有的低产田每公顷平均单产不足８２５ｋｇ（公斤），与管理技术较高的高产田平均每公顷产２２５０ｋｇ水平差距极大。总结有关实践经验，北部棉区 In the northern part of our province, the frost-free period in the northern part of the province is shorter and the growth period is tighter. Some cotton fields often fail to keep up with their management due to management measures, resulting in a large number of flowers after frost and blooming, seriously affecting yield and quality. According to the survey, the average yield per hectare of some low-yielding fields is less than 825kg (kg), which is greatly different from the average yield of 2250kg per hectare of high-yielding fields with high management techniques. Summarize the relevant practical experience in the northern cotton area