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我们在1955—1957年进行的试验表明,如果在采割松脂前一年春天在松树树干拟置割面的上面,开割伤口,则第一采脂年的松脂产量约提高15%,第二年的松脂产量约提高10%。试验是这样进行的:于1955
Our experiments conducted in 1955-1957 showed that if we cut the wounds on top of the pine tree trunk planted mow in the spring of the previous year, the yield of turpentine in the first greasing year increased by about 15% and the second Turpentine output increased by about 10%. The experiment was carried out in 1955