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系统观察表明，油松赤枯病病原菌孢子 ５ 月上、中旬开始飞散，５ 月下旬侵染当年生油松针叶，病害初期症状出现在 ６ 月下旬，病情变化与气象因子、立地条件有一定相关性。病害轻重和分布与林木所处位置有关，病情从重至轻的顺序为：南＞ 北＞ 东＞ 西；山脚＞ 山中＞ 山脊；海拔低＞ 海拔高；纯林＞ 混交林。
The results of systematic observation showed that the spores of the pathogen of P. oleracea began to fly in mid-May and mid-May. In late May, the pine needles were infected, and the initial symptoms of the disease appeared in the end of June. The change of the disease was related to the weather factors and site conditions Sex. The severity and distribution of diseases were related to the location of the trees. The order of the disease from heavier to lighter was: South> North> East> West; Foot> Mountain> Ridge; Elevation at low altitude> Pure forest> Mixed forest.