What causes cherry blossoms to drop their leaves early?

The cherry blossoms that should have dropped their leaves in mid-September have dropped them in mid-August for four or five consecutive years, with no pest damage or obvious disease found, and no such phenomenon has appeared in nearby nurseries. What is the reason?

Xu Shaoyuan, technical director of Zhejiang Senhe Seed Industry Company, answers: There may be three reasons for early leaf drop in cherry blossoms. First is pest damage. The larvae of longhorn beetles can, under the bark at the base of the trunk, cause the entire branch to drop its leaves early; if the larvae are in the main root, they cause the entire tree to drop its leaves early, so checking for pest damage is very important. Generally speaking, a nitrogen fertilizer content of 3‰ is relatively suitable; if it is not mixed evenly, the concentration at the bottom becomes higher, which can also cause the tree to drop its leaves early. In addition, dry climate, uneven water supply, water shortage in the nursery or excessive rainwater accumulation, causing poor tree growth and obstructed nutrient transport, can also lead to early leaf drop. It is worth mentioning that this summer the south had widespread rain, which easily causes soil compaction, hinders the exchange of soil gases with air; only by strengthening fertilizer and water management can the tree's resistance be enhanced and normal leaf drop occur.