【摘要】 <正> 樟子松(Pinus sylvestris Var. mongolica)是大兴安岭地区的乡土树种,由于它具有耐干旱、抗寒、速生等性,近年来培养了大量苗木上山造林。随着大兴安岭地区的迅速开发和更新造林,对苗木的需要更加迫切。但是自1980年发现苗木针叶上有退绿更多还原

【Abstract】 A new disease of the needle Cast of mongolian-pine(Pinus sylvestris var. mongolica) has been observed in Daxinganling Area in recent years. It caused serious damage in several forest nurseries.Inoculation showed that the pathogen is LoPhoderrniurn seditiosum Minter, Staley et Millar (imperfect stage is Leptostrorna rostruPii Minter). The fungus overwinters by mycelium or unmatured peritheeia in diseased needles. Ascospores are dispersed by rain and air current from seedling to seedling in seedling bed from June to August, but the maximum is in July. Conidia are discharged in the whole growth season, but the maximum is between June and July. The temperature and moisture are important to ascospore germination and infection.Among the eleven fungicides that were used to control the needle cast in the field test, 75％ chlorothalonil (500—700 times) solution was the most effective.更多还原