安庆市第三代二化螟田间为害状况及水稻损失率的研究

Damages and yield lossing caused by the third generation of Chilo suppressalis (Walker).

本文阐述了 3代二化螟在双季晚稻上发生危害症状和出现的新特点 ,明确了各种受害症状均有产量损失 ,损失率为 12 .85%～ 59.6 3% ;建立了田间宏观受害状与产量损失之间的关系 ,为产量损失调查提供了参考依据。导致减产的主要原因是结实率和千粒重显著降低。药剂防治试验、示范表明 ,在本代卵孵盛期或初见红叶期选用杀虫双或三唑磷防治 1次 ,防治效果可达 72 %以上。于以上两个时期防治2次 ,防治效果可达 91%以上 ,同时可减少越冬虫源基数 76 .75%～ 83.2 %。作者认为 ,加强末代 (3代 )二化螟的防治既是当年保产的需要 。

This paper described the damages by the third generation of Chilo suppressalis (Walker) in late rice and the new characters, and defined the relationships between every kind of the damages and the yield lossing, which were 12 85%—59 63%.This provided the investigation of yield lossing with new methods.The main reasons of yield lossing were the obvious reduction in weight of thousand gains and the fructiferous rate.Under chemical controls, the control effect was more than 72% with one control operation by “sha chong shuang” or “triazophos” in one term of eggs high hatching or red leaves just appearing, and it was more than 91% with two control operations in two terms.Meantime, the Chilo suppressalis number over winter was reduced by 76 7%—83.2%. Controling the last generation (third generation) of Chilo suppressalis could protect yield, and was the important measures of integrated control of Chilo suppressalis over long period.