What is the reason for the yellow leaves of tomatoes

Tomato is a kind of vegetable with large planting area in our country. No matter what is planted, many problems are often encountered in the planting process. Tomatoes are no exception, for example, when growing tomatoes, there are often bad phenomena such as curling leaves, freezing injury and yellow leaves. So what the editor brings to you today is the causes and control methods of yellow leaves of tomatoes. Let's take a look at it with the editor.

1. Yellow leaf causes

Soil salinization

Tomato cultivation can not be continuous cropping, in the perennial use of the soil, nitrogen, phosphorus, potassium and other substances in the soil are fixed. A large number of salts that cannot be absorbed by tomatoes are formed, resulting in soil salinization. When tomatoes are planted continuously for more than three years, the probability of soil salinization is more than 30%. Resulting in tomato growth malnutrition, the emergence of yellow leaf phenomenon.

Element deficiency disease

The demand for nutrition in tomato growth is relatively large and comprehensive. If there is a lack of nitrogen, potassium, magnesium and other nutrients, the middle and lower leaves of the plant will gradually yellowing, and the lack of iron and zinc will lead to the yellowing of the upper leaves. And if excessive application of chemical fertilizer, it will aggravate the yellowing phenomenon. The root cause of element deficiency lies in the soil and plant roots. Poor soil quality or poor root development will affect the nutrient absorption of plants, resulting in yellow leaves.

Root disease

Root diseases are also the main causes of tomato yellowing, such as root rot, Fusarium wilt and so on. The mild disease will affect the root development, lead to nutritional malabsorption, and naturally appear the phenomenon of yellow leaves. If the disease is serious, it will not only cause yellow leaves, but also lead to dead trees. In addition, too much watering leads to soil consolidation or improper use of medicine, which will lead to yellow leaves of tomatoes.

2. Prevention and control methods

Soil salinization

Before planting, the soil should be deeply turned over, a flood should be watered, and the soil salt should be sunk to the bottom of the soil. Then increase the application proportion of farm manure, increase the content of organic matter in the soil, promote the adsorption of salt, and protect the root growth. Then appropriate application of microbial fertilizer, let microorganisms decompose salt substances.

Element deficiency disease

First of all, we need to reduce the amount of chemical fertilizer and increase the proportion of organic fertilizer. Carry on the scientific fertilization method according to the tomato growth stage, for example, in the tomato full fruit stage, we should carry on the appropriate extra-root topdressing, supplement nitrogen, potassium and magnesium fertilizer, and reasonably supplement the corresponding nutrient elements according to the soil fertility. Seaweed fertilizer and other substances can also be used to irrigate roots to promote the rooting of tomato plants. Finally, it is necessary to do a good job in the prevention and control of root diseases and insect pests, reduce the incidence of diseases and insect pests, protect the roots, and control the amount of watering, not too much watering, timely drainage, rational use of drugs, and so on.

The above is a brief introduction to the reason for the yellow leaves of tomatoes. There are many reasons for the yellow leaves of tomatoes. When we plant tomatoes, we should pay attention to non-continuous cropping and solve the problem from the root. That's all for today's introduction. This article is for reference only. I hope it can help you all.