Tomato leaf rolling is a physiological response to the adverse environmental or biological hazards of crops. Effective measures should be taken in time according to the reasons for leaf rolling. First, high-temperature rolling leaves. At temperatures above 30°C, tomatoes will grow slowly, increasing photorespiration and affecting nutrient accumulation. For temperatures above 35°C, the water transpiration of the plant leaves was accelerated, and the water transport speed in the root could not keep up with the transpiration rate of the leaves, which could easily cause dehydration on the surface of the leaves. Control methods: 1 To protect the tomatoes, it is necessary to add shade nets in time, increase the vents of the greenhouses, and be careful not to remove the insect nets; 2) spraying and applying 6000 times fluid to protect the leaf diseases. Second, the low temperature leaf. Appropriate temperature for tomato growth is: about 25°C during the day and 16°C～18°C during the night, and the critical point for stopping the growth is 10°C. For less than 10°C, the mesophyll cells will be chilled and the leaves will bend downwards until the mesophyll cells are iced and whitened. Control methods: In the cold season, when the greenhouse temperature is insufficient to ensure the tomato growth requirements, it is recommended to add a geothermal heating, or temporarily increase the temperature of the fire to promote growth; spraying 7500 times liquid Bi care. When the leaves are yellow, the brassinolide or high-quality amino acid foliar fertilizer can be used for conditioning. Third, excessive fertilizer caused by leaf rolling. The fertilization plan is based on the target yield of tomato, and the amount of flushed fertilization should be based on the current number of ears. Excessive fertilization results in excessively high local soil fertility, resulting in root burns and leaf spotting on leaf margins. Control methods: Reasonable fertilization, controlled amount of water-soluble fertilization is an important measure to reduce the damage. Fourth, herbicide damage caused by rolling leaves. Spraying herbicides on farmland can easily cause drift along with air currents, causing phytotoxicity to nearby tomato plants, causing the tomato leaves to roll up and stiff and brittle. Control methods: 1 General leaf mild symptoms can be sprayed gibberellin 4000 times, or Bihu 5000 times to ease the symptoms, to promote leaf rolling. 2 Strengthen top-dressing fertilizer and promote plant growth. Fifth, the virus infected leaf. Tomatoes infected with fern leaf virus disease, the plant appeared different degrees of dwarfing phenomenon, from top to bottom of the leaves all or part of the upward curl of the leaves. Control methods: At the beginning of the disease, 6% oligosaccharides WP wettable powder 1000 times, or 20% doped copper acetate wettable powder 500 times, 2% amino oligosaccharide water 300 times, 3% triazole nucleus Aqueous agent 500 times liquid, 2% nannanmycin agent l50 ~ 250 times liquid, 5% bacteriostatic water agent 300-500 times liquid, and other fungicides optional spray control, control once every 7 days , even against 2-3 times. Maternity & Baby Products Packaging Maternity & Baby Products Packaging,maternity & baby products packaging guide,maternity & baby products packaging ideas,maternity & baby products packaging kit taicang hexiang packaging material co.,ltd , https://www.medpackhexiang.com