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信阳地区种植水稻历史悠久,常年以单季春稻和稻麦两熟为主,七十年代有少量双季稻种植.三化螟是当地水稻的主要害虫之一,不同年份发生量悬殊很大.大发生年能使水稻严重减产.弄清其变化原因,可为发生量的中长期预报提供依据.从有记载的1954年到1980年的二十七年中,信阳地区三化螟几起几落.据资料记载:1954年为大发生,在固始县五个区一百个乡调查,受灾面积占67.4%,螟害程度十分严重.自1955年起,发生量大幅度下降,
The planting of rice in Xinyang has a long history and is dominated by single season spring rice and double crop of rice and wheat, while a small amount of double cropping rice is planted in the seventies. Borer borer is one of the main pests of local rice, with great disparity in different years. Year of the big can make a serious crop of rice to find out the reasons for the change, can provide the basis for the medium and long-term forecast of occurrence.From 1954 to twenty-seven years in 1980, the few borer in Xinyang several According to data records: occurred in 1954, a survey of 100 townships in five districts of Gushi County, the affected area accounted for 67.4%, the degree of borer damage is very serious since 1955, the occurrence of a substantial decline,