How to manage greenhouse vegetables after the start of summer? Key points for summer greenhouse vegetable management

After May Day, temperatures rise noticeably, and compared with spring, the management of greenhouse vegetables should also change. At present, greenhouse vegetable management should focus on the following three points:

1. Prevent damage from high temperatures and strong light. If vegetables in the greenhouse are exposed to high temperature and strong light for a long time, heat stress and strong-light damage are likely to occur. For example, due to excessive leaf transpiration in cucumbers, the root system's ability to absorb and supply water decreases, making stems and vines prone to wilting; tomato fruits are prone to blossom-end rot under the effects of high temperature and drought; sweet pepper fruits are prone to sunscald, and kidney beans show flower and pod drop due to high temperature. In short, vegetable growers should be vigilant against the damage caused by high temperature and strong light to greenhouse vegetables. Effective measures include: covering with shade nets, splashing mud slurry or ink, spraying cooling agents, and so on. In addition, under such conditions, because the day-night temperature difference is too small, plants are prone to excessive vegetative growth. It is recommended that vegetable growers spray Aiduoshuo at 1500 times dilution to regulate growth.

2. Prevent damage from diseases and pests. As the temperature in the greenhouse rises, diseases that occur under low temperature and high humidity conditions, such as gray mold, sclerotinia rot, and cottony leak, gradually decrease, but this instead causes leaf mold, powdery mildew, and bacterial diseases to begin spreading. Vegetable growers especially need to be reminded that viral diseases of vegetables, which easily occur under high temperature and drought conditions, require even greater prevention. Recommendations: spray chlorothalonil at 600 times mixed with streptomycin at 3000 times once every 5—7 days; to control powdery mildew and leaf mold in cucurbit and solanaceous vegetables, Amimiao Shou at 1500 times can be used; Virus A at 500 times + Ningnanmycin at 300 times + zinc-containing foliar fertilizer can effectively deactivate and inhibit the occurrence and spread of viral diseases. For insect pests, vegetable growers are advised to focus on controlling whiteflies, thrips, and mites. In addition to physical and biological control methods, pesticides such as Caixi, imidacloprid, pyridaben, and abamectin can be used for control.

3. Prevent pesticide damage and fertilizer damage. When vegetable crops are under high temperature and strong light, their own metabolism intensifies. If during this period the dilution ratio for spraying or flower-dipping pesticides is still based on the winter dilution ratio, or if the amount of fertilizer applied by irrigation or spraying is too large, it is very easy to cause leaf pesticide damage, hormone poisoning, or root injury. Here, vegetable grower friends are advised to use pesticides cautiously, especially flower-dipping pesticides or plant growth regulators with growth-inhibiting effects. When applying fertilizer by irrigation, pay attention to balanced fertilization and formula fertilization. For example, for cucumbers in the full fruiting stage, it is recommended to apply Fangrun (20:20:20) at 8—10 kg per mu by irrigation to promote fruit development and nourish the vines. For foliar topdressing, focus on fertilizers containing medium and trace elements such as boron, calcium, and magnesium.