Apple tree rot disease, commonly known as rotten bark disease, rotten bark disease, and bunch bark disease, is the most serious disease that harms apple trees, often causing dead apple branches and dead trees. Using difenoconazole and taking the measure of "two sprays and two brushes" can effectively reduce the occurrence of rot disease. For example, 10 difenoconazole water-dispersible granules should be sprayed 5,000 times in the entire garden before fruit trees germinate and after falling leaves; in June to July, use 10 difenoconazole water-dispersible granules 1,000 times a month. Apply the liquid to the large branches and trunks of fruit trees. After discovering the rotten spots, scrape them off correctly, especially until the bark turns yellow-green. The edges of the scrapings should be neat, and then apply 5-hexaconazole microemulsion 300 times.