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近几年来东北地区落叶松人工林陆续发现枯梢病,而且蔓延速度很快,危害也相当严重,轻者造成树木枯梢影响树木生长,重者树冠变形,甚至死亡。目前已成为东北地区落叶松人工林一种危险性新病害。一、分布及危害据1978年调查,我省丹东、本溪、扶顺、辽阳、营口、旅大,铁岭等地落叶松林都不同程度的发生枯梢病。该病干1973年在东沟县孤山子和集贤林区首先发现,当时只是零星块状分布,并没有引起人们的注意。1978年在东沟县调查落叶松林4260亩,发病率为87.1%,感病指数56.4。而桓仁县调查7200亩,发病率为73.5%,感病指数58;2年生苗5亩,发病率30%。我省落叶松林总面积277万亩,约5万亩发病,而且正以惊人的速度逐年发展,已成
In recent years, Larch plantations in the northeast of China have been witnessing the emergence of blight disease one after another, with rapid spread and serious damage. The light trees cause the trees to grow in the light of the withered branches of the trees, even the canopy deformation and even death. Now it has become a new dangerous new disease of larch plantation in Northeast China. First, the distribution and damage According to the survey in 1978, our province Dandong, Benxi, Fu Shun, Liaoyang, Yingkou, Luda, Tieling and other larch forests are varying degrees of blight. The disease was first discovered in Goubang and Jixian forests in Donggou County in 1973, when it was only sporadic patchy distribution and did not attract people’s attention. In 1978, 4260 mu of larch forest was surveyed in Donggou County, with an incidence rate of 87.1% and a susceptible index of 56.4. And Huanren County survey 7200 mus, the incidence rate was 73.5%, susceptibility index 58; 2-year-old seedlings 5 acres, the incidence rate of 30%. Larch forest in our province a total area of 2.77 million mu, about 50,000 mu of disease, and is at an alarming rate year by year, has become