柑桔树常出现大小年现象,生产上采取的一系列技术措施,如大年增大修剪量和施肥量、疏果、加强夏季修剪等,均能收到一定效果。笔者经在3个大年(1985、1987、1989年)进行的试验,发现七月重施肥可明显缩小大小年结果的差距,现将1987年的试验结果介绍如下。 Citrus trees often appear the size of the year phenomenon, a series of technical measures taken in the production, such as the year to increase the amount of pruning and fertilization, thinning, strengthening the summer pruning, etc., can receive some results. The author conducted experiments in three major years (1985, 1987 and 1989) and found that re-fertilization in July could significantly reduce the size-year difference. The results of the 1987 trial are summarized as follows.