The greenhouse tomato leaves check the reasons for prevention

In recent years, tomato leaf curling in greenhouses has occurred from time to time, not only affecting plant photosynthesis, impeding the synthesis of nutrients, interfering with normal plant growth and growth, but also seriously affecting tomato quality and yield. The reasons for the analysis are closely related to the physiological barriers of plants and the influence of external environmental conditions. It is necessary to find out the reasons and prevent and control the diseases.

1. Due to cold invasion. This kind of situation occurs in the initial stage of nursery and exhalation. Generally, it starts from the tip of the leaf and rolls up. The leaves are chicken-like. In severe cases, the dry tip has white edges. The main reason for this was the violent release of the air and the plant's sudden encounter with cold and dry air. The prevention and control method is as follows: When venting, pay attention to the external climatic conditions, adopt a gradual approach, and immediately close the tuyere when the leaves are found, raise the temperature, and spray the plants with warm water in time to restore them naturally.

2. It is caused by a viral disease. Virus disease mostly occurs in the seedling stage and the adult plant stage. After the onset of disease, the plant leaves curl, shrinkage becomes smaller, and when serious, it becomes a tube, and the plants cluster or stop growing. The prevention and control method is: soaking seeds with 10% trisodium phosphate solution for 30 minutes before sowing; killing the virus as soon as possible; eradicate the virus transmission medium; spraying virus A or plant disease spirit every 7 to 10 days after planting for prevention and treatment.

3. In the flowering period of tomato, if the plant hormone is misused or the concentration of 2,4-D is arbitrarily increased, or if the sprayer containing residual herbicide is misused when pesticide is sprayed, tomato rolling will also be caused. In order to prevent such a situation from happening, the concentration used should be properly grasped according to the weather conditions.

4. Pruning too much weight, leaving few leaves on the plant, and excessive water and fertilizer will cause most of the leaves of the whole plant to roll up and become severely tube-shaped. Some of the fruit in the expansion period, there is also a phenomenon of upward rewinding leaves. Control methods: Reasonable fertilization, proper amount of watering, timely cultivating; timely removal of sprouts on tomato vines, picking early picking, pruning, topping can not be too heavy, to minimize the wound surface.

5. Tea leaves caused by the yellow tea leaves. Camellia sinensis sucks sap in the leaves or young organs, resulting in malformation of the plant or fruit, narrowing of the leaves, thickening, stiffness or distortion. Control measures: remove weeds and fallen leaves. It is best to do a pre-emergent smoke agent shed, eliminate eggs, and do a good job of chemical control.