Biological Characteristics and Fungicide Screening for Corynespora Leaf Spot Pathogen on Pogostemon cablin

CHEN Xu-yu1,GAN Bing-chun1,SUI Chun2,WEI Jian-he1,2(1.Hainan Branch Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences & Peking Union Medical College/Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine, Wanning 571533,Hainan,China;2.Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences & Peking Union Medical College,Beijing 100193,China)

corynespora leaf spot pathogen of Pogostemon cablin;Corynespora cassiicola;biological characteristics;fungicide screening

[Aims] The aim is to master the biological characteristics of pathogenic fungus Corynespora cassiicola(Berk.& Curt.)Wei and to control the disease of corynespora leaf spot on patchouli.[Methods] Flat method and flat-stand method were used to observe the biological characteristics and to screen suitable fungicides,respectively.[Results] The investigation showed that the mycelia of C.cassiicola grows fastest in the PDA medium.The optimum temperature for the mycelial growth was 28 °C and the optimum pH value was 6.The mycelia grows well under the full light or light/dark alternation.Fungicides screening showed that the EC50 values of prochloraz-manganese 50% WP,mancozeb 80% WP and difenoconazole 10% WG were 0.1115,0.1594 and 0.1946 mg/L,respectively.[Conclusions] Fungicides of prochloraz-manganese 50% WP,mancozeb 80% WP and difenoconazole 10% WG showed good control against mycelial growth.