What are the control methods for cherry root cancer?

How to control cherry root cancer?

The tumor at the root crown of cherry is caused by a bacterium of the genus Agrobacterium, known as cherry root cancer. The most obvious symptom of this disease is the formation of spherical or hemispherical tumors at the root crown. In the early stage, the tumors are white and soft, then gradually enlarge and become lignified. The surface of the diseased tumors is rough, brown or dark brown. Cherry root cancer often causes poor growth of the aboveground part of the plant, yellowing of leaves, and in severe cases, plant death.

The pathogenic bacteria of cherry root cancer survive and overwinter in the surface layer of the tumors of diseased plants and in the soil. When the surface layer of the tumors is decomposed, the bacteria enter the soil and can survive in the soil for several months to about 1 year. The pathogenic bacteria are mainly spread by irrigation water or rainwater, and can also be spread through grafting tools or underground pests. They often invade plant tissues through grafting wounds and mechanical wounds. The disease is severe under conditions of heavy clay soil, excessive humidity, and excessive use of barnyard manure.

Control measures for cherry root cancer: First, strengthen seedling quarantine and select disease-free plants. Soak various mechanical wounds of plants in 1% copper sulfate solution for 5 minutes, rinse with clean water, and then plant. Second, when mildly diseased plants are found, the tumors should be removed promptly, and wood ash or sulfur powder should be applied to protect the wounds. Severely diseased plants should be pulled out with roots and burned. For soil disinfection of diseased soil, chloropicrin can be applied evenly at 60-120 grams per square meter and then mixed with the soil.