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1986年6、7月间,我随种予园害虫综合防治(?)察组考察了美国东南和西北两大林区9个(?)子园。现简单报导一下所见所闻。一培育良种的目的性明确美国的种子园大多数建于六十年代。他们建立种子园的目的非常明确,就是为了改良林木,提高生长量。据美国30个林业公司在南方联合试验的结果,种子园生产的第一代种子可以提高林木生长量12%,所以许多
In June and July 1986, I went to inspect the nine (?) Orchards in the two major southeastern and northwestern US territories with the Integrated Pest Management and Prevention (IGP) team. Now simply report what you see and hear. A Purpose of Cultivating Varieties It is clear that most of the seed orchards in the United States were built in the 1960s. Their purpose of establishing a seed garden is very clear, in order to improve the trees, increase their growth. According to the results of a joint experiment by 30 forestry companies in the United States, the first seeds produced in Seed Garden can increase the growth of trees by 12%, so many