It can appear on our dining table all year round. Among them, tomatoes are also a kind of nutritious vegetables, and the vitamins contained in tomatoes are also very high. Eating more tomatoes is also good for our health. For some small spots like dark brown or black, round to oval, like drinking water, melons gradually expand, with dark brown edges, grayish brown centers, concentric wheel patterns and yellow halo at the edges. When the humidity is high, there are gray-black mildew spots on the diseased spots.

Diseases often originate from lower leaves. Tomato early blight is a common tomato disease, which can occur from seedling stage to middle and late stage of tomato. Generally, it is easy to happen when the humidity is high and the plant's disease resistance is weak. After the occurrence, it can harm the leaves, stems and fruits of tomatoes, and even lead to spots, sometimes accompanied by a little white mold, and then gradually form concentric annular spots, gradually turn dark brown, and the subcutaneous pulp also turns brown. When the humidity is high, the disease grows white mold, and the diseased fruit remains intact, not softened and easy to fall off. Leaves grow and rot in water after infection, and white mold layer appears on the diseased spot when the air humidity is high.

The diseased spot on the stem was soaked in water, brown, sunken and rotten. Causing plants to wither. The fruit is susceptible to diseases, and it is oily dark green at first, then brown, concave, with irregular moire. The fruit does not become soft and is yellow halo-shaped, with concentric rings in the middle, and the ring surface is burr-shaped and uneven. Stem diseases are mostly brown to dark brown irregular round or oval diseases with gray-black mold on the surface. Petiole is damaged, with oval wheel spots, dark brown or black. Generally speaking, due to vein restriction, the lesion is polygonal. With the development of the disease, the color of diseased branches and leaves gradually turns yellow-green or brown. Under the influence of humid environment, purple-green or black mildew spots will grow on the diseased spots on the back of leaves. These mildew layers are the propagation of viruses, and there are many aphids in high temperature and drought, which is beneficial to the disease. In the growth and later period, the diseases of spring tomatoes are more, but the harm is not serious, and the diseases of summer tomatoes are more, which is the main obstacle to the production of summer tomatoes.