What is the reason why tomatoes turn yellow when they don't grow? What should I do?

Mr. Gao in Jiaozuo Wuyi County has 10 mu of tomatoes in the greenhouse. He has just planted them for half a month, and found that they are yellowing. What is the reason why tomatoes turn yellow when they are not growing? What should I do?

According to the research of teacher Ying Fangqing, an expert in tomato cultivation, there are many factors for yellowing leaves:

1. Climatic factors. There are many cloudy days, the seedlings are slow, and the storage substances inside the leaves are consumed too much.

2. Fat damage. In the production, the organic fertilizer is not mature well, which produces heat damage and harmful gases (ammonia, hydrogen sulfide, nitric oxide).

3. Bacterial diseases. Tomato bacterial canker occurs on leaves and begins on the edge and tip of leaves.

4. Fungal diseases.

5. when element deficiency, especially magnesium deficiency, yellow plaques appear on the leaves. The occurrence of macular plaques in the lower part is magnesium deficiency, while in the upper young leaves it may be viral.

How to prevent and cure it?

1. Attention should be paid to watering and venting caused by fertilizer damage. Harmful gases are melted into water, which can reduce heat damage.

2. The disease should be sprayed with chemical drugs. Bacterial diseases, commonly used in the production of copper preparations can be killed, antibiotics can be used Zhongshengmycin, streptomycin sulfate and so on.

3. Magnesium deficiency is common in tomatoes in recent years, but magnesium sulfate can be sprayed on the leaves.