【摘要】 通过在田间进行人工接种模拟自然发病流行的情况，确定大豆灰斑病发病为２级时是引起大豆减产的病情低限。采用二元多项式逐步回归法，建立了生育期（生长发育天数）和病级单独及联合起来对单株产量、瘪荚率和百粒重影响的优化方程，同时建立了灰斑病对大豆田间群体产量损失估计模型。并且通过相关性分析，确定始粒期病情对大豆产量影响最大，建立了关键点模型更多还原

【Abstract】 By field inoculation to simulate the natural occurrence of frogeye leaf-spot of soybean in order to get plots with different disease severity theinfluence of each class of disease severity on yield,abortive pod rate and weight of 100 seeds were assessed. The result show that severity of class 2 induced obvious yield loss. Three optimized models for the influence of different class of severity in various growth stages were established by binary polynomial stepwise regression analysis with growth stage and severity class as independant variables and yield, abortive pod rate and weight of 100 seeds as dependent rariables. The models of population yield loss due to infection of soybean frogeye leaf spot were also established by the same way. By analysis of correlation it was shown that the seed beginning stage was the critical growth stage for yield loss assessment, the disease severity of that stage caused the greatest yield loss. Two models for critical point were developed.更多还原