There is a bonsai tree in my home. I don't know why, there is always some white mucus on the stump, and some ants are attracted.

The part of elm branches with gum flow is related to the growth direction of branches, and the base of branches growing vertically is more seriously damaged than the upper part. The side of the lateral branch facing the surface is heavier than the upward part; Branches and branches that often suffer from sunburn are also seriously damaged. At the time of onset, the diseased part of the branches swelled and colloid flowed out. At first, chewing gum was transparent, and finally it turned into a dark brown lump. In severe cases, the bark and xylem turn brown and rot, the trees become weaker and weaker, the leaves turn yellow, and finally the whole plant dries up and dies.

Gummosis is a disease caused by fungal cysticercosis. The germination temperature of meristem is 8℃-40℃, and the optimum temperature is 24℃-35℃. The pathogen overwinters in the diseased part of the branch, and conidia begin to spray from late March to late April of the following year, which spreads through the splash of rain and invades from the lenticels or wounds of the branch. The peak of infection is from May to June, and the pathogen will not be infected after the middle and late September.

The prevention and treatment of gummosis can adopt the following methods:

1. Scrape the colloid in time and coat it with protective agent, such as stone slag or carbendazim wettable powder.

2. Spraying 50% carbendazim l000 times solution or thiophanate-methyl L000- 1500 times solution in May-June during the growth period of trees for 4 times in a row, the control effect can reach over 80%.

3. During the dormant period of trees, that is, before germination, apply 100 times of antibacterial agent 402 to brush the diseased spots to kill overwintering germs and reduce the source of infection.

4. Strengthen tree management. Drainage in time, increase the application of organic fertilizer and phosphorus and potassium fertilizer, strengthen the tree potential and improve the disease resistance of the tree.