我县栽培鸭蛋柑(普通甜橙),虽已有两百余年的历史,但过去大都采用实生繁殖,大株稀植(每亩15—17株),幼树管理粗放,高干整形(主干高4—6尺),重度砍削,致使进入结果期迟,—般8—10年开始结果,20年才达到盛果期。这种方法栽培甜橙,在我省过去每个周期性大冰冻前,尚能获得一定产量。自1969年以来,冰冻周期趋向缩短,对这种方法, Although my county has cultivated duck egg oranges (common sweet orange) for more than two hundred years, most of the trees used spawning plants (15-17 plants per acre), extensive management of saplings, Trunk 4-6 feet high), severe cutting, resulting in the late entry into the results - like the beginning of the results of 8-10 years, 20 years to reach the full fruit period. This method of cultivation of sweet orange, in the past in our province before each period of large ice, still can get a certain yield. Since 1969, the freezing cycle tends to be shortened. For this method,