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纹枯病系我省水稻的首要病害。为适应生产水平提高和水稻品种变更的需要,1979和1983～1984年,我们对不同施氮量对田间病程与产量损失的影响和药剂防治指标进行了研究。 一、田间病程 (一)病穴、病株的增长:亩产千斤左右的单季杂交水稻,纹枯病病穴率、病株率达到20％的日期分别在7月25～28日与7月30日～8月5日,病指达20是在8月15～21日。病穴率、病株率达60％的日期分别在8月8～18日与8月12～20日,病指最高值出现在9月中下旬,即病情停止期。
Sheath blight is the most important disease of rice in our province. In order to meet the need of increasing the production level and changing rice varieties, we studied the effects of different nitrogen application rates on disease course and yield loss and pesticide control indexes in 1979 and 1983 ~ 1984. First, the field of disease (A) disease points, the growth of diseased plants: about one kilogram of per acre about single-season hybrid rice, sheath blight disease point rate, the strain rate reached 20% of the date in July 25 to 28 and 7 Month 30 ~ August 5, the disease refers to 20 in August 15 to 21. Disease point rate, the rate of diseased plants reached 60% in August 8 to 18 and August 12 to 20, the highest value of the disease appeared in late September, that is, the disease stopped.