榆林风沙区樟子松枯死主要发生在10～15年生幼龄林上,7月上旬至8月下旬为感病高峰期,翌年4月中旬至5月中旬为死亡高峰期。病菌孢子在整个生长季均能放散与传播,降雨节律及降雨量直接影响孢子的扩散与数量。人工接种发现:病菌的侵入期主要在6月中旬至8月中旬,潜育期半个月,侵入途径是伤口,病株感病部位及枯死枝是病原菌的越冬场所,密度高,植被盖度大的林分感病重。 The moss of Pinus sylvestris in the sandy area of ​​Yulin occurred mainly in 10-15-year-old young trees. From early July to late August, it was the peak of the disease. From mid April to the middle of May the following year was the peak of death. Bacteria spores can spread and spread throughout the growing season, rainfall rhythm and rainfall directly affect the spore proliferation and quantity. Artificial inoculation found: the invasion of bacteria mainly in mid-June to mid-August, half of the incubation period, the invasion is the wound, the diseased parts of disease and dead branches are pathogenic bacteria overwintering places, high density, vegetation coverage The big forest is very sick.