In continuous rainy weather, how should the vegetable greenhouse be managed?

    With the arrival of nationwide rainfall, many areas are facing continuous rainy weather for one week or even more than half a month. Continuous rainy days will have serious adverse effects on the growth of greenhouse crops. So what measures should be taken in vegetable greenhouses?

    1. Water accumulated in the greenhouse

    Although the greenhouse will not be directly exposed to rain on cloudy and rainy days, the accumulated water outside the shed will infiltrate from below, making the soil water holding capacity in the shed reach a saturated state, which will make the crop roots unable to breathe and cause retting. Therefore, in rainy weather, the drainage ditch inside and outside the shed should be cleaned in time to avoid water accumulation due to blockage.

     2. High incidence of diseases

     Although it is cloudy and rainy,but the temperature in the greenhouse is still very high during the day, and the air humidity is close to saturation. High temperature and humidity are hotbeds for various pathogens. Therefore, in rainy days, the vents in the shed should be opened in time, and watering and fertilizing are prohibited. In the early stage of continuous rainy days, the method of "medicament fumigation" can be used to prevent diseases. For example, the spray method should be used to control the concentration, and at the same time strengthen the ventilation to promote the rapid drying of the liquid on the leaves and avoid the damage caused by the long-term non-drying.

      3. Decreased nutrient absorption

      Plant roots rely on the pull of leaves to absorb nutrients. Continuous rain and rain cause the air humidity in the greenhouse to be close to saturation. Therefore, the leaves cannot evaporate water, and the roots' ability to absorb nutrients decreases or even stagnates. At this time, a small amount of nutrients can be supplemented by applying phosphorus and potassium fertilizer on the leaf surface. When the rainy days are over, phosphorus and potassium fertilizers should be added first to avoid partial application of nitrogen fertilizers, which may lead to excessive growth.

     4. Weak photosynthesis

     In cloudy and rainy days, due to cloud cover and insufficient light intensity, the photosynthesis of the plants is weakened, resulting in slow growth, hollow and deformed fruits. For fruits and vegetables, the canopy leaves that shade each other can be pruned, and fruit thinning methods should be appropriately adopted to improve photosynthetic efficiency, concentrate nutrient supply, and increase the rate of commercial fruits. At the same time, spraying sodium nitrophenolate can improve the photosynthetic capacity of leaves.

     Standardized Management Plan for Greenhouse Vegetables in Cloudy and Rainy Days

     1. Proper water control

     The weather is continuously hot and the ground is easy to dry. Farmers water more frequently. When the rainy weather occurs, some farmers will also water. In this case, the growth of crops and the probability of pests and diseases, such as stem bases, are even more exacerbated. Rot, vine blight, bacterial disease, etc. Therefore, proper water control must be carried out. 

     2. Tomatoes are leggy

Controlling prosperous drugs causes crops to be in a high temperature period and prone to excessive growth. Everyone knows that prosperous proliferation drugs can be used to control growth. Let’s take tomatoes as an example. From planting to slow seedling, it usually takes 5-7 days to plant 8 After a few days, the phenomenon of excessive growth will appear. According to the growth of the tree, the use of drugs to control the growth is generally about 10 days after the planting.

Standardized program: spraying: fish protein biological liquid, trace elements, potassium dihydrogen phosphate, safety control (dosage according to instructions)

     3. Flower bud differentiation is not good

     Everyone is often not very accurate about the time to control the growth. Normally, the effect of the growth control can be seen within 3 days of spraying. If the growth point is black, it proves that the medication has been effective. If the growth point is yellow and the leaves are thin, then it is necessary Carry out 2 medications. In rainy weather, the absorption and utilization rate of any drug crop is very low, which increases the difficulty of our management. Therefore, we must pay more attention to the control method, that is, the use of drugs for control in cloudy days.

Standardized management plan: (1) Enhance resistance to stress: spray fish protein biological liquid (2) spray safety control.

     4. Prevention and treatment of diseases

     Bacterial diseases are prone to appear in continuous rainy weather, which is mainly based on prevention. According to the management in these aspects, there is a certain guarantee for the increase in the production of vegetables in the greenhouse.