小白菜花叶病流行曲线分析及两参数植病流行方程的非线性拟合

小白菜花叶病流行曲线分析表明,Weibull方程拟合效果最好,Logistic方程次之,Gompertz方程又次之。 探讨了两参数植病流行方程的非线性拟合方法:台劳级数展开法和麦夸尔特法。在小白菜花叶病等18个植病系统的94组流行曲线中,非线性方法的拟合结果均优于线性方法。

STUDY ON DISEASE PROGRESS CURVES OF CHINESE-SMALL-CABBAGE MOSAIC AND NONLINEAR METHOD FOR THE FITTING OF TWO-PARAMETER EQUATIONS OF PLANT DISEASE PROGRESS

It was shewn by applying different models ( Logistic, Gompertz and Weibull) to data obtained by field disease investigation that Weibull model described the progress curves of Chinese-Small-Cabbage Mosaic ( mainly caused by Turnip Mosaic Virus and Cucumber Mosaic Virus ) the best, and the Logistic better than Gompertz model. Nonlinear method, Gauss-Newton algorithm and Marquardt' s algorithm, was proposed for the fitting of two-parameter equations of plant disease progression. A comparison was made of nonlinear and linear method by using 94 sets of plant disease progress data o f 18 disease systeme; results showed that the nonlinear method was better than the linear method in all casas.