论文部分内容阅读
棉蚜(Anhis gossypii Glover)是上海郊区棉花早中期主要害虫之一,但近几年来,很多人改变了对棉蚜为害的看法,有的认为有虫无害,有的认为天敌能控制棉蚜为害,所以可以不进行防治。作者从1977～1981年对棉蚜的为害进行了研究,为综合防治提供正确的防治指标。本试验在小区及大田中进行。结果表明,在1～2张真叶卷叶时,单株减产率为31.02％～51.46％,而在3～4张真叶时为24.80％～42.97％,在大田条件下,不同卷叶株率(x)与减产率(Y)的关系式为: y=0.7034×-1.4641利用y=0.7034×-1.4641关系式,结合当地棉花的生产水平,可确定防治指标。
Anis gossypii Glover is one of the main cotton pests in the suburbs of Shanghai in the early and middle stages. However, in recent years, many people have changed their view on the damage caused by cotton aphids. Some think that pests are harmless and some believe that natural enemies can control cotton aphids Damage, so you can not prevent. The author studied the damage of cotton aphid from 1977 to 1981, and provided the correct control index for comprehensive prevention and control. The test in the district and the field. The results showed that in the case of 1 ~ 2 true leaves, the yield reduction per plant was 31.02% ~ 51.46%, while in the case of 3 ~ 4 true leaves it was 24.80% ~ 42.97%. Under the field conditions, The relationship between rate (x) and rate of decrease (y) is: y = 0.7034 × -1.4641 Using the relation of y = 0.7034 × -1.4641 and the production level of local cotton, the control index can be determined.