Diseases of rhododendron and its control methods

1. Physiological diseases

Due to poor environment and lack of nutrients, the disease is called physiological disease. This disease, the whole plant will have obvious symptoms, and the symptoms are almost similar.

This disease has yellowing, that is, azaleas need a slightly acidic growth environment, if maintained in the north, there may be alkali in our soil and water, resulting in yellowing of leaves. There is also lobular disease, that is, zinc deficiency, manganese deficiency, lack of trace elements, its leaves will become smaller and thicker, further affecting growth and flowering.

Prevention and control methods: what causes, to adjust this factor, is to meet the growth of rhododendron. For example, if the environment is slightly alkaline, we will use weakly acidic soil; zinc and manganese deficiency will supplement it with zinc and manganese.

2. Infectious diseases

Diseases caused by pathogenic microorganisms are called infectious diseases, such as leaf spot, anthrax and botrytis. They have an important feature: that is, its symptoms begin to spread around from a central point, and the symptoms at the central point are more serious. If it is not dealt with, the scope of the expansion will gradually spread out.

Prevention and treatment: this disease also needs to be controlled by drugs, and appropriate agents should be taken according to the cause of the disease.

3. Coal pollution disease

Coal fouling disease is not caused by individual fungi, but by prickly sucking pests such as aphids and scabies on the leaves, which leave some excreta on the leaves in the process of piercing, which are infected with coal fouling pathogens.

Prevention and control methods: first control insects, eliminate pests, and then use chemicals to kill coal fouling disease bacteria.