我乡二台子村魏中阳园有20年生国光苹果树90株,株行距4.5×5m。由于生长过旺且株行距较小,造成树体对光能利用率低,树冠内长枝比例大,产量低。针对这种情况,我们于1989年3月下旬在该园内的39株国光树上做了施用多效唑(PP333)试验。现将具体作法简结如下: 一、施用量:每株树施用13克。二、施用方法:先将13克多效唑兑7.5公斤水,然后在树冠投影下开沟一周,开沟深度 Weizhong Village, Weizhong Yang Park has 20 years Guoguang apple tree 90, spacing of 4.5 × 5m. Due to overgrowth and smaller row spacing, resulting in tree light utilization rate is low, the crown long branches within a large proportion of low yield. In view of this situation, we applied PP333 to 39 Guoguang trees in the park in late March 1989. The specific practices are summarized as follows: First, the amount of application: each tree application 13 grams. Second, the application method: first 13 grams paclobutrazone against 7.5 kg of water, and then ditch a week under the crown projection, ditch depth