水稻二化螟防治指标研究——Ⅱ.二化螟为害和产量损失率测定及经济阈值静态模型探讨

STUDIES ON INDEX OF CHEMICAL CONTROL OF STRIPED RICE BORER, CHILO SUPPRESSALIS WALKER Ⅱ. STUDIES OF YIELD LOSS BY THE LARVAL POPULATION AND THE STATIC STATE MODELS OF ECONOMIC THRESHOLD

本文通过1984～1985年早,晚稻三个品种上不同卵块密度下二化螟幼虫造成水稻的不同被害丛率,枯鞘茎率和枯心率调查,并进行协方差分析后指出:二化螟化学防治指标不仅可以使用卵块密度,还可以使用防治适期的被害丛率和桔鞘茎率。在对水稻产量损失率测定的基础上,探讨并建立了二化螟的化学防治经济阈值静态模型。卵块密度(卵块数/亩)指标: 被害丛率(%)指标: 枯鞘茎率(%)指标: 1986年进行了验证性大田防治试验。

An investigation of the percentage of injured rice hills, plants with withered leaf sheath and plants with withered central stalks of three early and late rice varieties caused by striped rice borer from different density of egg clusters was conducted in 1984—1985. Covarience analyses showed that not only the egg cluster density but also the percentage of injured hills and plants with withered leaf sheath could be used as index for chemical control of the pest. Static state models of economic threshold of chemical control were built up on the bases of determination of yield loss. Field control experiment was conducted in 1986 and threeformulas were developed.