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意大利现有森林面积600万公顷,总覆盖率20%左右,其中杨树约15万公顷,占全国森林总面积的2.5%。每年杨树出材量高达300万立方米,占全国木材年产量的50%。由于病害的发生给意大利的杨树生长和利用带来了很大影响,据1977年意农林部资料,叶褐斑病的发生总面积达110,297公顷,约占杨树栽培面积的75%,使杨树年平均生长量减少25—50%,平均术材产量损失约30%。为此,意大利病理学家对杨树病害进行了大量深入细致的研究,取得了显著成绩。
In Italy, the existing forest area is 6 million hectares and the total coverage is about 20%, of which poplar is about 150,000 hectares, accounting for 2.5% of the total forest area in the country. Poplar annual output of up to 3 million cubic meters, accounting for 50% of annual timber production. Since the occurrence of diseases has greatly affected the growth and utilization of poplar in Italy, according to the information from the Ministry of Agriculture and Forestry in 1977, the total area of leaf brown spot disease reached 110,297 hectares, accounting for about 75% of the poplar cultivation area. The average annual growth of poplar reduced by 25-50%, the average loss of about 30% of the production of timber. To this end, the Italian pathologist carried out a large number of poplar disease in-depth study, and achieved remarkable results.