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关于稻纵卷叶螟的经济阈值,近十年来开展了广泛研究,但国内外的研究结果都不大一致,低的定为每亩5000头,即每丛稻0.2头;高的如马来西亚定为每亩75000头,我国江苏亦提出杂交稻为每亩75000头(胡建章,1986);有的品种如“661”在生长偏旺的情况下,每亩有虫50000头有增产作用(陆自强1986)。笔者1981—1985年在洞庭湖区连年进行稻纵卷叶螟主害代第二代为害“湘矮早九号”的为害损失率测定及其防治指标研究,现
As for the economical threshold of rice leaf roller, extensive research has been carried out in the past ten years, but the research results at home and abroad are not very consistent. The low is set at 5,000 heads per mu, that is 0.2 per bundle of rice; 75000 heads per acre. Jiangsu Province of China also proposed 75,000 heads of hybrid rice per acre (Hu Jianzhang, 1986). In some varieties such as “661”, there are 50000 heads of pests per mu yielding increased production (Lu Ziqiang 1986). The author from 1981 to 1985 in Dongting Lake area year after year for the second generation of the dominant rice leaf roller borer damage, “Xiang short morning on the 9th” damage loss rate determination and control index research, the