宁夏回族自治区解放前原有果树树种单纯,且多系不耐贮运和品质较差的品种,因而引进并大量繁殖品质优良的西洋苹果,就成为十分迫切的任务。但自1951年引种以来,果园内定植的幼龄苹果连年发生越各干枯死亡现象,往往在植后的第一、第二两个冬天埋土越冬后,却在第三或第四个冬天开始露地越冬时遭致冻害,丧失了大部甚至全部树冠。根据1957年在我区的调查,越冬死亡率达50—71%,严重者全部冻死;仅个别小气候较优良地区死亡率为26.6%。所以幼龄苹果越冬问题,实际上已成为宁夏区发展苹果的主要障碍。灵武园艺试验场于1951年定植的10亩国光、元帅苹果共162株,历年来,特别是四年生幼树在宁夏稀有的1954严冬的考验下,均获得了安全越冬的良好效 Before the liberation of Ningxia Hui Autonomous Region, the original fruit tree species was simple, and the most of the impotence storage and transportation of poor quality varieties, so the introduction and mass propagation of high quality Western apple has become an urgent task. However, since its introduction in 1951, young orchard young apples planted in orchards have experienced more and more dry deaths each year. After the first and second winters of planting, winter burying began, but they started on the third or fourth winter Frost damage caused when exposed to winters, lost most or all of the canopy. According to the survey conducted in our district in 1957, the overwintering mortality rate reached 50-71%, with severe cases of all being frozen to death; the mortality rate in only some microclimate was 26.6%. So young apple overwintering problem, in fact, has become the main obstacle to the development of apples in Ningxia. Lingwu horticultural test ground planted in 1951, 10 acres of Guoguang, Marshal Apple a total of 162 strains over the years, especially four-year-old young trees in Ningxia rare 1954 winter severe test, were safe and wintering good effect