论文部分内容阅读
华北落叶松和油松同为张家口地区用材林基地建设的主要树种,但幼苗往往遭受立枯病(又称猝倒病)的为害,各地每年虽进行防治,但发病率仍然很高。据1965—1980年,在蔚县、崇礼等地有关公社、大队、林场的30余处苗圃(500多亩)的调查,以及1963年在南京汤山林场的调查,幼苗发病率为20—40%,严重地块达60—70%,甚至全部毁灭。近年来,蔚县每年都有因立枯病的为害,造成落叶松、油松育苗失败的情况发生,对用材林基地建设中苗木供应有很大影响。该病是松树育苗工作中的一个严重威胁。
Larix principis-rupprechtii and Pinus tabulaeformis are the main tree species for the construction of timber forest base in Zhangjiakou area. However, the seedlings often suffer from damping-off disease (also known as damping-off disease), and the incidence is still high despite the prevention and treatment every year. According to a survey of more than 30 nurseries (500 mu) of communes, brigade and forest farms in Yuxian County and Chongli County from 1965 to 1980 and a survey in Tangshan Forest Farm in Nanjing in 1963, the incidence of seedlings was 20-40 %, A serious block reached 60-70%, or even destroyed. In recent years, Yuxian every year because of the damping off caused by the disease, resulting in larch, pine seedling failure occurred, the timber base construction in the seedling supply has a great impact. The disease is a serious threat to pine seedling work.