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实践证明,在农药防治褐稻虱中,防治3代对抑低4代虫量,减轻4代为害程度效果明显.但对防治3代的虫量标准未作定论.另外,对3代防治田块的农药用量和成本也未予评价.为此,1979年我们在萧山县迳游公社下俞大队就解决以上两个问题进行了试验,结果如下. (一)试验方法 1.选定试验田块:于3代低龄若虫盛发后10天左右,对该大队种植的晚稻嘉湖4号等常规稻品种上的褐稻虱虫口密度和虫态比
Practice has proved that in pesticide control brown planthopper, the prevention and control of three generations of 4 generations to reduce the amount of parasites, reduce the degree of harm to the 4th generation effect is obvious, but the prevention and control of three generations of insects standards no conclusion.In addition, The amount of pesticides and the cost of the block has not been evaluated.To this end, we Xiaoshan Yu Xia tour in Xiaoshan County in 1979 to solve the above two problems were tested, the results are as follows: (a) test method 1 selected test plots : In the third generation of nymphs about 10 days after the flourishing, on the brigade planted late rice Jiahu 4 and other conventional rice varieties of brown rice pest population density and insect status