A STUDY ON GETTING BUMPER CROPS BY CLOSE PLANTING OF YOUNG HAW TREES

Zhang Yuming Chen Jinan Liu Xingzhi Wang Xuefeng (The Haw Experimental Group of Shenyang Agr. Col.) Xu Haiqing Shun Weizhong Liu Zhengong Luo Enwei Pie Dianqing (The Technical Cooperation Group of Fushun District)

Haw (Crataegus pinnaiifida Bge. var. major N. E. Br.) originated in China. It is a special local fruit tree of China with a very long planting history, but the unit productivity is comparatively low. This expariment was carried out in 1978 at Songzhuan haw orchard in the suburb of Fushun District. An experimental plot 2 mu in size was planted with two year-old grafted trees. At the begining planting was performed in two patterns: 1. With a spacing of 1.5m×2m, 330 trees were planted in 1.47 mu; 2. With a spacing of 0.5m×2m, 296 trees were planted in 0.53 mu. In tree years (1979～1981) the annual per mu yields under the first plan were 159.0 jin, 427.4 jin and 1, 038.2 jin respectively, while the corresponding figures under the second plan were 369.2 jin, 863.6 jin and 976.8 jin respectively. The measures for obtaining early and high yield in 4 years (1978～1981) were as follows: 1. Only strong and healthy grafted seedlings were selected. 2. Mangement measures were adopted, such as digging the soil, applying suitable amount of fertilizer, draining in time, pruning intensively, spraying with GA solution during the blooming period, foliage dressing with N, P, K when necessary, preventing and eliminating diseases and insect pests, etc. 3. Close-planting was adopted for haw trees during their young stage, i. e., permanent plants and temporary plants were planted alternatively at the same time, with a view to raising per unit area yield by increasing the number of trees in a given area. When the branches and leaves are overcrowded, the temporary plants may be pruned, shortened or eliminated to regulate the colony structure of the whole plot.