研究和实践证明,把某些作物通过间作、套种或混合等形式合理搭配种植,往往可以控制或减轻某些病虫害的发生,从而收到“不施农药,胜施农药”的效果。 麦棉套种 对控制棉花苗期蚜虫十分有利。麦套棉由于小麦的屏障作用,不仅直接影响棉蚜迁入,而且棉田温度要比单作田低1℃左右,再加上麦行天敌的作用,苗蚜不用施药防治即可控制。据辽宁省2000年4处试验点观察,全年不治虫,单作棉田平均减产31.3％,麦套棉田平均减产18.1％。 棉花绿豆间作 5、6月份,单作田棉棵小,不利于天敌 Research and practice have proved that it is often possible to control or mitigate the occurrence of some pests and diseases by reasonably collocating some crops through intercropping, intercropping or mixing, so as to receive the effect of “not applying pesticides and winning pesticides.” Wheat and cotton intercropping control of cotton seedling aphids is very favorable. Wheat wheat cotton barrier effect, not only directly affect the cotton aphid immigration, and the cotton field temperature is lower than the single field about 1 ℃, coupled with the role of the wheat line natural enemies, seedling aphids can be controlled without application of pesticides. According to the observation of 4 pilot sites in Liaoning Province in 2000, the annual pest free production was reduced by 31.3% on average for single cotton fields and 18.1% on average. Intercropping cotton mung bean in May and June, a single cotton field for cotton, is not conducive to natural enemies