Research on the outbreak regularity of pine wood nematode in south of Jiangxi province

According to the investigation about the basic situation of pine wood nematode in Gannan, in order to determine the characteristics, distribution, changes of symptoms of dead pine infected pine wood nematode. We also researched the relationship between incidence and species, age, Monochamus alternatus and other pests, site situation about infected pine. Researched the occurrence characteristics on more years dead type and shoot dieback type, explored the development law of pine wood nematode varies with time in the tree. The results showed that: the susceptible pine by nematode Bursaphelenchus xylophilus in south of Jiangxi province dominated by age of Masson pine, Pinus massoniana represented symptoms in July to November period, pine represented symptoms after infected 2~3 months. The age of most withered branches style, dead next year style Pinus massoniana was 15~25 years old, had brawnier branch,thicker foliage, less diseases and insect pests than dead in the same year style. The symptoms of withered branches, dead next year on Pinus massoniana were associated with thickness of tree and bark, thick skin type and width crown, thick branches types of Pinus massoniana was easier to appear above symptoms than thin type and narrow crown, thinning type.