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为弄清棉苗期害虫在各种前作内的发生特点,以利准确测报,分类指导大田防治,现将笔者1982～1988年的研究报导如下。一、研究方法(一)调查取样:历年在观察区内,自棉苗出土开始至见蕾止(按前茬小麦、油菜和冬闲地),逢每旬5、10日观察一次,定点不定株,五点随机取样,各类型田每点10株共50株,记载全株成、若虫数量。(二)统计标准:发生期按16％、50％分别作为始盛期、高峰期的统计标准。发生量按百株(5天)累计虫量的标准统计。
To clarify the occurrence of cotton seedling pests within the various characteristics of the former, to facilitate the accurate measurement of the newspaper, classified guidance to control the field, now the author 1982 ~ 1988 research reports are as follows. First, the research methods (A) survey sampling: calendar year in the observation area, since the excavated from Miaon Miao see Lei only (according to the former crop of wheat, rape and winter fallow), observed every 5,10 days, fixed-point strains , Random sampling at five o’clock, each type of field 10 points per point a total of 50 strains, records of the whole plant into the number of nymphs. (B) of the statistical standards: the occurrence of 16%, 50%, respectively, as the peak, peak statistical standards. Occurred by the number of 100 (5 days) the cumulative amount of standard statistics.