Disease and Pest Control of Rhododendron chinense

1. Leaf swelling

It generally mainly harms the flower buds, young leaves and new shoots of Rhododendron ovata. At first, light yellow translucent circular spots will appear on the front of the leaves, and then turn yellow. Still a little bit sunken. This will cause the leaves to start turning yellow and fall early. In severe cases, patches of spots will form on the petioles, which will become very deformed and thickened.

Prevention and control methods: Before the disease begins, especially when it sprouts and leaves, you can spray some pesticides. If diseased leaves are found, they must be cleaned up immediately. If the disease occurs before germination, you can spray some pesticides to control it. After the disease occurs, you need to continue spraying with other pesticides.

2. Leaf spot and brown spot

Both diseases directly affect its leaves, petioles and stems. The spots on the leaves are round, and then they will gradually expand to appear as irregular large spots, and some ring patterns will appear. Then the spots will gradually change from reddish brown to dark brown, with gray-brown in the middle. No matter which disease it is, it may cause the entire plant to completely wither and die.

Prevention and control methods: From May to August, we can find some corresponding pesticides, make certain configurations, and then spray them once every 10 days or so, a total of 7 to 8 sprays will be enough. This way, we can control the development of the disease well. In order to prevent some leaves from turning yellow, other solvents can be added.

3. Coin Depression

It sounds like a really strange disease. Generally, as long as the young branches and leaves are damaged, they will be immediately covered with dense white or pink diseases, most of which are caused by aphids.

Prevention and control methods: First, remove the diseased leaves, then spray some medicine on it, and also master certain spraying techniques, so that it will not be easy to get new diseases.