Harm and Prevention of Toxic Gases in Greenhouses
Plastic greenhouses to cultivate vegetables, often due to improper fertilization methods, neglect of ventilation, so that excessive toxic gas inside the shed, endanger the vegetables, but often misdiagnosed as a disease, resulting in deficit or even no income.
First, the harm
1, nitrogen: due to the application of excessive amounts of urea, barium sulfate and other fast-acting fertilizers, or improper fertilization methods, such as the application of organic fertilizer without decomposition, there will be ammonia decomposition under high temperature conditions in the greenhouse, it will damage the vegetables, so that the edge of the tissue Water spotted spots appeared, and the whole leaf wilted and died when severe. Often misdiagnosed as frost or other diseases, cucumbers, tomatoes, zucchini, etc. are sensitive to ammonia.
2. Nitrous gas: The excessive application of ammonium nitrogen fertilizer once will reduce the effect of certain bacteria and cause local acidity in the soil. When the PH value is less than 5, it will produce nitrous acid gas, can cause white spots on the leaves of vegetables, and the whole leaf becomes white and dead. It is often misdiagnosed as powdery mildew. Vegetables sensitive to nitrous acid are eggplant, cucumber, zucchini, and celery. , pepper and so on.
3. Ethylene and chlorine: If the quality of the plastic film or plastic film is bad, or there is residue of the plastic film in the ground, it is exposed to sunlight. Under the high temperature conditions in the greenhouse, volatile gases such as ethylene and chlorine are easily generated. When the concentration reaches a certain level, yellowing between the leaf edges or veins of the vegetables can occur, which in turn turns white. In severe cases, the entire plant withers. Often misdiagnosed as bacterial keratoses, the damage to cucumber is particularly severe.
Second, prevention:
1, a reasonable fertilization. The organic fertilizer applied in the greenhouse must be fermented and rotted, the fertilizer must be of high quality, and the urea should be mixed with phosphorus and calcium. Basal fertilizer should be applied 20 centimeters deep, and the depth of topdressing chemical fertilizer should reach about 12 centimeters.
2, ventilation. In sunny and warm weather, ventilation should be performed in conjunction with adjusting the temperature, and ventilation and air exchange should be performed in rain and snow.
3, the use of safe and non-toxic agricultural film and plastic film, timely removal of waste plastics and their residues in the shed.
First, the harm
1, nitrogen: due to the application of excessive amounts of urea, barium sulfate and other fast-acting fertilizers, or improper fertilization methods, such as the application of organic fertilizer without decomposition, there will be ammonia decomposition under high temperature conditions in the greenhouse, it will damage the vegetables, so that the edge of the tissue Water spotted spots appeared, and the whole leaf wilted and died when severe. Often misdiagnosed as frost or other diseases, cucumbers, tomatoes, zucchini, etc. are sensitive to ammonia.
2. Nitrous gas: The excessive application of ammonium nitrogen fertilizer once will reduce the effect of certain bacteria and cause local acidity in the soil. When the PH value is less than 5, it will produce nitrous acid gas, can cause white spots on the leaves of vegetables, and the whole leaf becomes white and dead. It is often misdiagnosed as powdery mildew. Vegetables sensitive to nitrous acid are eggplant, cucumber, zucchini, and celery. , pepper and so on.
3. Ethylene and chlorine: If the quality of the plastic film or plastic film is bad, or there is residue of the plastic film in the ground, it is exposed to sunlight. Under the high temperature conditions in the greenhouse, volatile gases such as ethylene and chlorine are easily generated. When the concentration reaches a certain level, yellowing between the leaf edges or veins of the vegetables can occur, which in turn turns white. In severe cases, the entire plant withers. Often misdiagnosed as bacterial keratoses, the damage to cucumber is particularly severe.
Second, prevention:
1, a reasonable fertilization. The organic fertilizer applied in the greenhouse must be fermented and rotted, the fertilizer must be of high quality, and the urea should be mixed with phosphorus and calcium. Basal fertilizer should be applied 20 centimeters deep, and the depth of topdressing chemical fertilizer should reach about 12 centimeters.
2, ventilation. In sunny and warm weather, ventilation should be performed in conjunction with adjusting the temperature, and ventilation and air exchange should be performed in rain and snow.
3, the use of safe and non-toxic agricultural film and plastic film, timely removal of waste plastics and their residues in the shed.
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