核桃林分产量的提高,组成种植园的品种和类型的汇集和核桃培育期的缩短在很大程度上取决于苗木的遗传性。因此,根据综合的林学措施不仅必须改善树木的生长条件,而且要提高树木的遗传性。这时,用珍贵的抗寒类型和高产类型的种子和接穗建立的种植园具有重要的作用。 为了获得大量 The increase in the yield of walnut stands, the pooling of species and types that make up the plantation, and the shortening of the walnut cultivation period are largely dependent on the heritability of seedlings. Therefore, not only must the tree growth conditions be improved according to the integrated forestry practices, but also the heritability of the trees. At this time, plantations established with precious cold hardiness types and seeds and scions of high yield type play an important role. In order to get a lot