雪松枯梢病的研究

STUDY ON THE DIEBACK OF CEDAR CAUSED BY BOTRYTIS LATEBRICOLA JAAP.

雪松枯梢病1986年在浙江的杭州、富阳、临安等地首次发现。引起雪松春梢上的针叶束和嫩梢大量枯死。11块标准地调查结果,平均株发病率为80.2％(31.8—100.0％),平均感病指数27.0(7.9—52.2)。经过分离培养、接种、再分离的程序试验,确认该病是由蛛形葡萄孢茵(Botrytis latebricola Jaap.)所引起。B.latebricola的发现在我国是新记录。 病原孢子萌茅的温度范围10—30℃,最适温度20—25℃;相对湿度90％以上孢子才能萌芽;在pH 3—10的清水中孢子均能萌芽,最适值为pH 4—5。5月份喷2—3次70％甲基托布津500倍液,防治效果为35.0—46.7％。

The dieback of Cedar, Cedrus deodara (Roxb.) Lond, was first found in May 1986 in Hangzhou, Fuyang and Linan, Zhejiang province. It caused the death of needles in bunch and tender spring shoots in great quantity. The results of investigation on 11 standard plots showed an average incidence of 82.2% (31.8-100.0%) and disease index of 27.0 (7.9-52.2). The pathogen has been examined through Koch's postulates and identified as Bo-trytis latebricola Jaap., a fungus thus with new record in China.The temperature and relative humidity range for spore germination of the pathogen are 10-30℃ and>90% respectively with the optimum temperature between 20-25℃. The pH value for spore germination is 3-10 with the optimum of 4-5.The disease control effect reached 35.0-46.7% when sprayed 0.14% wet table thiophanate methyl suspension 2-3 times in May.