山东省桑树细菌性疫病的发生与防治研究

Studies on Mulberry Bacterial Blight in Shandong Province

山东省已调查的 16个市 (县 )均有桑树细菌性疫病发生 ,病害主要有黑枯、枝裂、缩叶和叶斑 4种症状。每年 5月底至 6月初开始表现症状 ,7～ 8月份为发病盛期 ,发病率一般为 5 %～ 10 % ,重者可达 4 0 %以上。对病害症状、培养性状、致病性测定、生理生化特性的鉴定结果表明 ,山东省的桑树细菌性疫病病原菌绝大多数属丁香假单胞杆菌桑树致病变种 (Pseudomonassyringaepv .mori)生物型Ⅴ。疫病病原菌可随病残体在自然表土、灭菌土壤、自然土层 10cm深处以及桑树上越冬 ,存活到翌年 5～ 6月份。室内药效测定表明 ,70 %百菌清、卡那霉素和农用链霉素对桑树细菌性疫病病原菌具有较好的抑制作用。田间防治试验以 30 %琥胶肥酸铜悬浮剂的效果最好 ,达85 0 % ,其次为农用链霉素 ,防治效果达 4 5 %以上。

Mulberry bacterial blight was confirmed to occur in investigated 16 counties and cities in Shandong Province.There were mainly four symptoms of the disease,including black top,splitted stem,shrinked leaf and leaf spot.The disease symptoms appeared at the end of May or beginning of June,and became severest during July and August.The diseased mulberry rate usually accounted for 5% to 10%,occasionally could be more than 40%.Identification showed that the pathogen was Pseudomonas syringae pv. mori. Studies on infection cycle and control of mulberry bacterial blight and the inhibition of pesticides or antibiotics against the pathogen of the disease Pseudomonas syringae pv. mori revealed that pathogen in diseased tissues of mulberry could survive till May next year in sterilized soil,on the surface and 10 cm deep under the surface of field soil as well as on the mulberry trees.The pathogen even survived till June next year in sterilized soil and on the surface of field soil.It was suggested that Pseudomonas syringae pv. mori could over winter in diseased tissues in Shandong Province.On petri dishes,Likejun,70% chlorothalonil,kanamycin and streptomycin sulfate gave excellent inhibition against the pathogen,next came DT and ployoxin.In the fields DT gave the best control effects and next came 70% chlorothalonil.Their control effects were 85.5% and 45%,respectively.