How to prevent plant death after rainwater enters a vegetable greenhouse

Recently, due to frequent rainfall, a large amount of rainwater has entered vegetable greenhouses, causing fairly serious plant death in some vegetables. The pattern is that more plants die on both sides of the greenhouse, at the ventilation openings, and where rain leaks through the greenhouse surface. After rainwater enters the greenhouse, how can vegetable plant death be prevented? Vegetable growers can take the following measures.

First, drain the rainwater as soon as possible. After rainwater floods into the greenhouse, every effort should be made to remove the standing water in the shortest possible time, so as to avoid a large amount of rainwater accumulating in the planting rows and failing to seep down, which would cause vegetable root rot. Greenhouses with drainage conditions can channel the water into ditches; for greenhouses with no ditches nearby, water pumps, hoses, and similar equipment should be used immediately to drain the standing water from the greenhouse into ditches. After vegetables suffer root rot, the roots have poor resistance and are very easily infected by harmful bacteria in the rainwater and soil.

Second, hoe and loosen the soil at the right time. After draining the standing water, hoe and loosen the soil promptly when the soil in the greenhouse is alternately dry and moist, so as to increase soil aeration and promote the vegetable roots to resume normal growth as quickly as possible. The depth of hoeing varies according to the growth of the vegetable root system. For example, if newly transplanted vegetables are flooded by rainwater, since the roots have not yet spread over a large area, the hoeing depth can be somewhat deeper; if the root system has already spread and grown downward at the seedling stage, the hoeing depth can be controlled at about 3 cm, and it should not be too close to the plants. If the hoeing depth is hard to judge, it is advisable to hoe deeply after staying away from the plant roots.

Third, use chemicals to drench the roots in a timely manner. To prevent plant death after flooding, vegetables should be given a root drench promptly when the soil moisture is suitable. A 1000-fold dilution of 30% hymexazol aqueous solution or a 1000-fold dilution of 50% chloroisobromine cyanuric acid can be used for root drenching. During root drenching, an appropriate amount of rooting agent or chitosan can be added, such as Apollo 963 root-nourishing solution, to promote the repair and regeneration of damaged roots. Do not use too high a concentration when drenching with the chemical, otherwise it is also easy to damage the roots.

Fourth, increase the application of biological bacterial fertilizer. By making use of the bacteria-inhibiting-bacteria property of biological bacteria, 7 days after root drenching with the chemical, it can be applied along with watering. Note that bacterial fertilizer should not be used at the same time as fungicide, nor during the peak period of the fungicide's effectiveness; be sure to pay attention to the safe interval between the two. Suitable bacterial fertilizer products include Junba, Jikangjun 968 seedling-stage topdressing fertilizer, ETS microbial agent, and others.

In addition, vegetable growers must promptly repair damaged greenhouse film and set up rainproof walls and rain-blocking film on both sides of the greenhouse to keep rainwater from entering.

Wang Haitao, Mancheng County Agriculture Bureau