稻飞虱和纹枯病化控的策略及复合指标研究

采取田间小区和网室盆栽试验,研究稻飞虱和纹枯病混合发生的化控策略及复合防治指标。结果表明,水稻孕穗期(7月上中旬)用高效、长效、安全药剂扑虱灵和粉锈灵混合防治的“治前控后”化防策略保产效果最佳。试验证明,稻飞虱和纹枯病对水稻有明显的交互作用。组建了稻飞虱(白背飞虱、褐飞虱)虫量(X_(1-2))、纹枯病病株率(X_3)的复合为害损失及动态经济阈值模型。经田间小区、大田应用检验,不仅防效高,保产效果好,而且减少施药次数,保护了天敌,三大效益显著。

STUDIES ON THE CHEMICAL CONTROL TACTICS AND MIXED ECONOMIC THRESHOLD OF RICE PLANTHOPPER AND SHEATH BLIGHT IN PADDY RICE FIELD

In 1987-1991,chemical control tactics against the combined damage of rice planthoppers Sogatella furcifera(Horvath) and Nilaparvata lugens Stål and rice sheath blight Rhizoctonia solani Kühn as well as their mixed action threshold to rice were studied,based on field plots experiment and caged potted rice test.The results showed that one time spraying in booting stage of rice(early to middle July) with a mixture of applaud and bayleton,both of which are highly effective and persistent to the pests and safe to human,domestic animals and natural enemies,got the better efficacy for reducing the yield loss.It was found that there was significant interaction between planthoppers and sheath blight on rice yield.A dynamic action threshold model reflecting the combined effect of the number of planthoppers(x_1-2) and shoot incidence of rice sheath blight(x₃) on rice yield loss(y) was developed.The application results got by plot test and field were examined to be effective.