Pathogen Identification and Control of Asparagus Stem Blight in Hangzhou City
SHI Yanxia1，WANG Duo1，ZHANG Xujuan2，SHI Jianjun2，LU Yajing1，XIE Xuewen1，CHAI Ali1，LI Lei1，LI Baoju1*
1Institute of Vegetables and Flowers，Chinese Academy of Agricultural Sciences，Beijing 100081，China；2Hangzhou Jiahui Agricultural Development Co.， Ltd.，Hangzhou 311200，Zhejiang，China
Abstract：During 2018—2020，suspected asparagus stem blight case was discovered in Hangzhou Jiahui asparagus planting base．In order to definit the pathogenic species，this study conducted seperation，purification and identification on collected disease samples．It was definited that the disease was asparagus stem blight．According to pathogenic bacteria morphology character，and comparison results of amplification sequences between universal primer and specific primers，the homology of this pathogenic bacteria and Phomopsis asparagi（Sacc.）Bubak was 100%．It was identified as rhizome mildew of asparagine．The results of biological activity determination indicated that mycelium of this pathogenic bacteria was completely inhibited by 25% pyraclostrobin suspending agent．The inhibiting effect to this pathogenic bacteria was followed by 75% chlorothalonil wettable powder．EC50 was 0.13 μg · mL-1．Pot experiment verified that 25% pyraclostrobin suspending agent had the best effect on controlling stem blight，reaching 94.56%．It could be used as a highly effective agent for preventing and controlling asparagus stem blight．
