Matters needing attention in vegetable planting in greenhouse in summer

1, high temperature and strong light are the biggest killers of vegetable production in summer. There are many hot weather in summer. If the temperature in the shed is high, the vegetables will flourish and drop flowers and fruits at high temperature. So we must do the following: First, we must strengthen ventilation. When the temperature in the shed exceeds 35℃, a sunshade net should be set at the top of the shed to cool down. When the temperature exceeds 18℃ at night, cooling measures should be taken to widen the temperature difference between day and night and ensure the normal growth of vegetables.

2. Rainstorm is the second biggest killer of vegetable production in summer. Rainstorm in summer often collapses the wall, which easily causes soil waterlogging, causes root damage or induces root diseases, and affects the growth of vegetables. Therefore, after entering the flood season in summer, it is necessary to listen to the weather forecast in time to prevent rainwater infiltration as soon as possible. The drainage ditch around the shed should be dredged in time to prevent rainwater from pouring into the shed.

3. The frequent high-temperature phytotoxicity is the third biggest killer of vegetable production in summer. Most pesticides are greatly affected by temperature. Generally, the higher the temperature, the stronger the penetration and stimulation to vegetable stems and leaves. First, read the instructions carefully before taking the medicine. Generally, it should be slightly lower than the concentration indicated in the manual. For example, the concentration of drugs is generally 800 times, and it should be reduced to 1000 times in summer to prevent high-temperature drug damage. Secondly, pay attention to the spraying time. Generally, spraying in summer should be carried out before 9: 00 am or after 4: 00 pm, and sunny days are generally not at noon, because this time is the most likely to lead to phytotoxicity. In addition, the flowering period of vegetables should be sprayed as little as possible or not, and the concentration of drugs must be mastered when spraying. In case of phytotoxicity, effective measures should be taken to remedy it in time. The remedial measures are as follows: First, spray leaching. In case of phytotoxicity of vegetables, the leaves should be washed with clear water in time. According to the decomposition characteristics of most pesticides in alkali, 0.2% alkaline surface or 0.5% limewater can be added to clean water. The second is to spray drugs to reduce the harm of drugs. If vegetables are excessively inhibited by chlormequat chloride, spraying 0.05% gibberellin can alleviate it. Third, strengthen the management of fertilizer and water. After the occurrence of phytotoxicity, vegetables should be watered once, so as to increase the water supply of plants, dilute the concentration of liquid medicine in plants, and apply nitrogen, phosphorus and potassium compound fertilizer with water to promote the growth and development of plant roots, improve the stress resistance of vegetables, and make the damaged vegetables recover as soon as possible. Counting the four killers of greenhouse vegetables in summer is the fourth killer of vegetable production in summer.

4. Summer is the season when aphids, mites, leafhoppers and whiteflies multiply. This kind of pest will endanger the growth of vegetables after sneaking into the shed. Therefore, comprehensive measures should be taken to prevent such pests from sneaking into the shed. If an insect net can be installed at the air outlet of the greenhouse, the specification of the insect net should be more than 20 meshes, which can basically prevent the above pests from sneaking in. For the pests that sneak into the greenhouse, yellow boards can be hung for trapping and killing, or 3% acetamiprid 1500 times solution 10% imidacloprid wettable powder 2000 times solution can be used for control. In addition, it is also an important measure to remove the habitats of weeds and other pests outside the shed in time to prevent such pests and virus diseases.