论文部分内容阅读
杉树的主要病虫害有立枯病、梢枯病、赤枯病、金龟子、白蚁、杉梢卷叶蛾、双条杉天牛等。一、立枯病立枯病是杉树苗期最严重的病害之一,染病率一般达10～30%,严重的达70～80%,常造成片状缺苗现象。如不及时防治,就会造成苗木大量死亡,使育苗工作全部失败。(1)痘状立枯病的症状有三种类型。茅腐型种子播下后,在土壤中受病菌入侵,使种子或嫩芽霉坏,不能发芽出土。猝倒型主要在种子发芽后约一个半月内,幼苗的苗茎在离地表一厘米左右处,初
The main pests of cedar trees are blight, blight, blight, beetles, termites, cedar leaf roller moths, caterpillars and other cedars. First, the dead blight Rhizoctonia deciduous fir is one of the most serious diseases, the prevalence rate of 10 to 30%, severe up to 70 to 80%, often resulting in flaky lack of seedlings phenomenon. If not timely control, it will result in a large number of seedlings died, so nursery work all failed. (1) There are three types of symptoms of pox blight. Maufacturing seeds sowed in the soil by bacteria invade, so that the seeds or sprouts bad, can not germinate unearthed. Cataplexy mainly in the seed germination about one and a half months after the seedling seedling stems in the ground about a centimeter at the beginning