早稻纹枯病流行预测及损失估计

prognosis and yield Loss Assessment of Early Season Rice Sheath Blight

本文研究了气象要素和初始病情对早稻纹枯病病情进展的影响，不同氮肥用量、不同早稻品种受纹枯病为害所致的产量损失，以及水稻不同生育阶段的病情与最终病情的关系。结果表明：早稻纹枯病病情进展呈Ｓ型曲线，其进展过程分为三个阶段；水稻不同生育阶段的病情与最终病情是高度正相关，据此建立了不同抗病水平品种的病情预测式；日平均温度和相对湿度及初始病情与流行速率关系最密切，据此建立了病害不同进展阶段的流行速率预测模式；不同品种受纹枯病为害所致损失不同，组建了不同品种的产量损失估计模型，施氮量对同等病情程度的损失影响不显著。

Eftect of meterological Conditions and initial disease index on early season rice sheath blight (RSB) development was studied. Meanwhile, researches on yield loss by Rhizoctonia solanl in different varieties, N application were Carried out, too. The results were as follows: 1. Development Curve of RSB is S trpe. 2. Disease index in different growth stage has high relations with than in rice yellow ripe ness stage, disease Prediction formulate for RSB were built based on the relationship. 3. The apparent infection rate equations in different disease development stages for RSB,and the model of yield loss assessment were set up.