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五、落叶松落叶病落叶松落叶病,原名为落叶松早期落叶病。是我国北方落叶松人工林中普遍发生的一种严重病害。 (一) 分布及为害该病在1895—1896年发现于德国。1924年起,长期在日本流行,对日本落叶松人工林造成严重危害。国内,在1945年最早发现于辽宁省草河口林场,至1958年已蔓延到辽宁省东部林区。我省于1953年在漫江林区发现该病,至1960年,在通化、吉林等东部林区开始流行。1964年时,东北三省落叶松人工林受害面积已达41.2％。现在,在东北三省,凡有落叶松人工林的地方,几乎都有该病的分布。此外,在华北、西北的局部地区也有该病的发生。这种病害除为害人工林外,也为害天然林。感病的林分提早落叶约50天,春季放叶时间也
Fifth, larch deciduous disease Larch deciduous disease, formerly known as larch early deciduous disease. It is a serious disease in the Larix principis-rupprechtii plantation in North China. (A) distribution and damage The disease was discovered in Germany in 1895-1896. Since 1924, it has been popular in Japan for a long time, causing serious damage to the Japanese larch plantation. Domestically, it was first discovered in Caoweikou Forest Farm of Liaoning Province in 1945 and spread to the eastern part of Liaoning Province by 1958. The province discovered the disease in Manjiang Forest Area in 1953 and by 1960 it became popular in the eastern forest areas such as Tonghua and Jilin. In 1964, the damaged area of larch plantations in the three northeastern provinces of China reached 41.2%. Now, in the three northeastern provinces, where there are larches plantations, almost all have the distribution of the disease. In addition, in North China, some areas in the northwest also have the disease. In addition to injuring plant diseases, this disease also damages natural forests. Premature leaves of fallen leaves about 50 days, leaves time in spring also