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据调查,我国危害棉花的害虫共有310种,每年因虫害造成的产量损失达10%—30%,严重时可达50%以上。现将几种主要棉虫的发生危害期和防治指标介绍如下:棉蚜一年可发生20—30代,通常按季节分为苗蚜和伏蚜。苗蚜发生在棉花出苗期至6月底,常年危害盛期在5月中旬至6月中下旬,7月份为伏蚜发生期,危害高峰期多出现在7月中下旬。防治指标:苗蚜,3片真叶前卷叶株率5%—10%,4片真叶后卷叶株率10%—20%;伏蚜,卷叶株率5%—10%。
According to the survey, there are 310 kinds of pests that endanger cotton in our country. The annual loss of pests caused by pests is 10% -30%, and in severe cases it can reach over 50%. Now the occurrence of several major insect pests and control indicators are as follows: Cotton aphid can occur 20-30 generations a year, usually seasonally divided into seedling aphids and aphids. Seedling aphid occurred in the cotton seedling until the end of June, perennial endangerment peak in mid-May to mid-June, July is the occurrence of the aphids, the most dangerous period occurred in late July. Control indicators: seedling aphid, 3 true leaves before the roll of plant rate of 5% -10%, 4 true leaves after the roll of the plant rate of 10% -20%; Aphid, roll leaf rate of 5% -10%.