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松苗立枯病是东北地区针叶树育苗上的重要问题,其中以落叶松、樟子松、和红松等幼苗发病较重,油松和赤松等幼苗发病为轻。幼苗发病征状有土内腐死、猝倒、立枯、地上腐烂、和一、二年生大苗发生枯萎落叶等五个类型。诱致松苗发生侵染性立枯病的病菌,有 Rhizoctonia、Pythium 和 Fusarium等三种菌类,其中 Rhizoctonia 尤为主要。松苗立枯病发生的轻重与育苗措施有密切关系,地势低洼或位于山脚下坡的苗圃或苗床,一般发病较重。种子经雪藏混砂催芽处理后,能提早种子萌芽、出土和齐苗,有降低发病程度的作用。光照多少对幼苗发病有影响。根据苗圃的调查观察,全光育苗发病率低,遮蔭育苗发病率高;但在沈阳试验结果还不能证实这一点,相反的半遮蔭育苗要好些。
Blight of pine seedlings is an important issue of coniferous seedlings nursery in northeastern China. Among them, larch, Pinus sylvestris var. Mongolica and Pinus koraiensis are heavier, while those of Pinus tabulaeformis and Pinus koraiensis are lighter. Symptoms of seedling emergence of soil erosion, cataplexy, standing withered, the ground rot, and one or two annual seedlings withered and decayed five types. Rhizoctonia, Pythium and Fusarium are the three pathogenic bacteria that cause the infested damping-off disease in pine seedlings, of which Rhizoctonia is the most important. Pine seedling blight incidence and nursery measures are closely related to the low lying or lying in the foothills of the nursery or seedbed, the general incidence of heavier. Seed germination by the sand after the sand mixed processing, early seed germination, unearthed and Qi Miao, reduce the incidence of the role. How much light on the incidence of seedlings affected. According to the nursery survey, the incidence of all-photo-nursery seedlings is low, and the incidence of shading and nursery is high. However, the test results in Shenyang can not confirm this point. On the contrary, the semi-shade seedlings are better.