Cancer: affects young and tender parts. After being damaged, leaf drop, fruit drop and abnormal growth often occur. In severe cases, the branches will wither and die. Prevention and control methods: Select disease-free seedlings; cut off diseased branches and leaves in spring and burn them intensively; pay attention to the prevention and control of insect pests such as leaf miners; spray 1:1:200 Bordeaux mixture every time when spring shoots are drawn (or before flowering) and after flowers fade. Once every 7 days, spray 2 to 3 times in a row, then cut off the shoots, and spray the same pesticide to prevent damage caused by rust lice. From June to August, 10 to 15 days after spraying Bordeaux mixture, spray once for 0.3 to 0.5 waves. Mido stone sulfur mixture.

Soot disease: It mainly damages the above-ground parts of fruits, branches, leaves, etc., and covers the surface with a layer of dark brown moldy material. This disease is related to the damage caused by aphids and scale insects. The secretions excreted by aphids and scale insects can induce the occurrence of the disease. When this disease occurs, it seriously affects photosynthesis and inhibits the normal growth and development of plants. Prevention and control methods: When aphids and scale insects occur, spray 40% Dimethoate EC 1000 times, once every 10 days, 2 to 3 times in a row; in the early stages of soot disease, use 1:0.5:150-200 Use Bordeaux liquid spray to prevent and control; at the same time, pay attention to pruning to promote ventilation and light transmission of the tree.