元帅苹果树新梢生长、结果与修剪的相互关系

用三种修剪方法连续四年试验,观察了元帅苹果树修剪、新梢生长、座果和产量之间的相互关系。无论初结果树或盛果树,重修剪都引起新梢生长强度增大,使初结果树花芽形成少,座果低;盛果树落花落果严重,最终表现低产。新梢生长小.树势衰弱,往往大小年结果,累计年产量也低;而缓放修剪长势中席的盛果树,年产量或累计产量都远远高于其它修剪处理。修剪与新梢生长,产量关系差异显著。用回归和增产效果比较分析,适应元帅苹果高产的新梢平均生长量是36.67—41.67cm,座果率为12%以上。因此,对长势过强或过弱的植株,采用适当修剪方法,促进树势转化,并维持在适宜的生长范围,是提高产量的基本修剪技术措施.

Studies on the Relationship among Shoot Growh,Fruiting and Pruning Treatments of Delicious' Apple

Preliminary fruit (8-year-old) and full-fruit (16-year-old) trees of ‘Delicious’ apple were employed to study the rela- tionship among shoot growth and fruiting and pruning treatments with three methods during 1972-1975 on Huangyang River Farm,Whwei,Gansu Province.Either beginning fruit or full-fruit trees were induced to grew vigorously by severe pruning.Therefore,the beginning fruit trees had less flower buds,the flowers and young fruit dropped heavily from the full-fruit trees,and the yields of both trees decreased in the end.Plants of regular-pruning had least amount of growth, because of less intensity of pruning,the yield was least, The plants growing modestly by little pruning had good yields,either annual or total yields.The difference among pruning treatments,shoot growth and yield was significant. The results of analysis of regression and yielding efficfency showed that the average limitation of shoot growth for the most yield of full-fruiting trees of ‘Delicious’ was 31.67—41.67 eentimetres and the ratio of set fruit was 12 percent. Therefore,the fundamental measurement for increasing yields of 'Delicious' is to maintain their growth in a right lim- itation by good pruning so that the vigorous and weak plants could be converted to modest growth.