| Cotinus coggyria Scop, which is the main specie of red leaf landscape in Xiangshan Park, plays an important role in ecological development of Beijing. However, lack of effective control measure, the Verticillium wilt which happened in recent years not only destroyed the red leaf landscape but also lead to the death of C. coggyria on the large scale, and it had become the serious biological disaster that influenced the landscape construction in Beijing. Therefore, in order to better understand of the disease mechanism and provide the basic theory support for ecological control and non-harmful management, this paper carried on some experiments including finding best soil treatment methods of wilt disease and screening selevtive medium for Verticillium. dahliae microsclerotia, clarifying the relationship between occurrence degree of Verticillium wilt and environment factors, testing on efficacy determination of laboratory and field experiment in Xiangshan Park in Beijing. Through the analysis on result of experiment and investigation in stands of C. coggyria plantation in Beijing, the conclusion was made as follow:1 Five selective media for isolating microsclerotia V.dahliae from artificially infested soil, these selective media including that modified soil extract agar(MSEA), cotton No.1, Christen media, Yang Jiarong media and alcohol agar media. Yang Jiarong media and Christen media were effective medias for isolating V.dahliae, the two media were simple and quick. The microsclerotia V.dahliae from infested soil could be effectively isolated while they were rarely infected by other pathogens. Wet-seiving, sucrose-floatation and soil dilution methods were compared in results stability, recovery rate and separating artificially infected soil. The results showed that stability of wet-seiving method was the better and its recovery rate arrived at about 71.33%, sucrose-floatation recovery rate arrived at 41.48%, soil dilution recovery rate arrived at 33.87%. On the whole, wet-seiving method was more effective and suitable than the other methods in studying growth and decline of V.dahliae in soil.2 Through investigated the relationship between incidence rate of health and infective C. coggygria with environment factor. The investigation results indicated that disease index correlates with 5 factors of plot. These factors were canopy density, slope direction, slope level, soil type. The result indicated that Verticillium wilt disease index has close relationship with soil water content, with rising the extent of soil water content, disease index was also increase; The result of soil physical chemical factor shows that the content of the available P and the available K were positively correlated to the disease index, the available P and the available K of soil decrease with increase of the Verticillium wilt disease index.3 The result of the indoor experiment on Weijunjing,EM,Thiophanate-methyl,CuSO4,Dijunling,Oxamyl,Azoxystrobin,Arbendazim shows that Weijunjing,thiophanate-methyl,Oxamyl,Arbendazim,CuSO4 have the best repress effect on V. dahlia. The effect of EM and Azoxystrobin are not so good; the effect of Dijunling is the worst .It even has no effect to repress the fungi. The result of experiment in field enviroment shows that the relative control effect of nine medicament was between -32.77%～37.01%. Changeable temperature and humidity have influence to relative control effect of medicament. |
