[Distribution and hazards]
Purple-leaf plum gummosis occurred in all the purple-leaf plum cultivation areas in China. It often harms seedlings such as purple leaf plum and plum. The yellow glue will flow through the cracks in the bark of the seedlings, reducing the tree vigor and affecting the viewing of the seedlings.
【symptom】
After the pathogen infects the plant, the phloem necrosis of the injured tree separates from the xylem, the bark is raised from the outside, the diseased part is dark brown, and yellow glue flows at the crack. In severe cases, glue can be seen in many places throughout the trunk, the bark is festered, the tree's vigor is weakened, the new shoots grow slowly or even stop growing, the leaves are small and yellow-green, and the flower production is small. It can infect the fruit and cause the fruit to flow gum.
【pathogen】
There are two types, one is a non-invasive pathogen, which is caused by frost damage, insect wounds, hail, and garden tool damage caused by wounds; the other is fungus, and the pathogen is Botryosphaeria ribs Gross.et Dygg.
【onset law】
The flow of glue caused by non-invasiveness is often caused by excessive wounds; the flow of glue caused by fungi is mostly caused by extensive management and weak plant growth.
【Prevention】
1. Strengthen water and fertilizer management, rationally pruning, and reduce pruning wounds. After pruning, you can apply medicaments to protect the wounds; avoid freezing in winter; prevent pests and reduce wounds.
2. Chemical control. The colloid can be peeled off and coated with 74% chlorothalonil emulsion 300 times liquid at the bark flow glue. During the growth period of the plant, it can be sprayed with 500 times solution of 65% Zinc WP.