1. Downy mildew of radish: This disease mainly damages radish leaves and spreads upward from the lower part of the plant. At the beginning of the disease, pale green to yellowish spots will appear on the leaves, and then they will expand into polygonal or irregular yellowish brown spots. In a humid environment, a white mold layer will appear on the back of the leaves. In severe cases, the lesion is continuous, causing the leaves to turn yellow and dry.
2. Radish black spot disease: This disease is caused by black spot fungus, which mainly harms radish leaves. At the beginning of the disease, round or nearly round dark brown spots will appear on the leaves, accompanied by yellow halo. In a humid environment, black mold will appear on the lesion. In severe cases, the diseased spots will connect together, causing the leaves to turn yellow.
3. Radish virus disease: the disease will obviously dwarf radish plants, and the leaves will be mottled or yellow-green deformed. Aphids are important vectors. Under the conditions of high temperature and drought, extensive management, a large number of aphids and flea beetles or weak plant growth, the disease is more serious.
In order to accurately diagnose radish diseases, it is suggested to consult a professional agronomist or plant pathologist. They can give accurate diagnosis and treatment suggestions based on more symptom information and on-the-spot inspection.