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调查表明,二代棉铃虫卵在番茄植株上的垂直分布特征是:上部多于下部,明显地分为两层,大约95%的卵分布于顶尖至第四复叶层上,根据 Iwao 的两级抽样模型计算得出:每块田抽取100株,每株只调查顶尖至第四复叶层上的卵数,即可满足相对精度 D=0.10的要求。测报与防治调查卵密度时,每块地可取100株,取样时,以每点4株(2株/行×2行),共25个点为好。这种抽样方法较全株调查方法提高工效1—2倍。
The survey showed that the second generation of cotton bollworm eggs in tomato plants vertical distribution characteristics are: the upper part of more than the lower part, clearly divided into two layers, about 95% of the eggs distributed in the top to the fourth compound leaf layer, according to Iwao’s two Level sampling model calculated: each field extraction 100, each plant only to investigate the top to the fourth leaf layer on the number of eggs, to meet the relative accuracy of D = 0.10 requirements. Reported and control survey egg density, the desirable 100 per block, sampling, the point of 4 per plant (2 / line × 2 lines), a total of 25 points as well. This sampling method than the whole plant survey method to improve work efficiency 1-2 times.