To cultivate vegetables in the plastic greenhouse, often caused by improper fertilization methods, ignoring ventilation, and shed toxic gas in excess, it makes damage to vegetables and often being misdiagnosed as a disease, thus resulting in poor or even total destruction.
Nitrogen Due to the excessive application of Nitrogen, or this type of fast fertilizers, such as urea, sulfuric acid, or improper fertilization methods. For example, the application of organic fertilizers without composting, under the condition of high temperature, it will produce ammonia which can damage vegetables, causing the leaf margin appear watery spots, or seriously died leaf. In this case, the vegetables are often misdiagnosed as frost and sick, or other illnesses, the ammonia-sensitive vegetables such as cucumber, tomato, Zucchini, etc..
Nitrous acid gas Too much application of ammonium-nitrogen will reduce the effects of certain bacteria, causing local soil acidity. When the PH value is less than 5, it will produce nitrous acid gas, which can make vegetable leaves white spots, serious situation of the whole leaves dead and white, often being misdiagnosed as powdery mildew. The plants sensitive to nitrous acid gas include eggplant, cucumber, Zucchini, celery, peppers and other.
Ethylene and chlorine If you buy low-quality agricultural film and ground cover cloth, or residue existed in the ground film, with sun exposure, under the condition of high temperature in the shed, it easily produces ethylene, chlorine and other harmful gases. When the concentration reaches a certain value, it can make vegetables yellow between the veins on the leaf margin, then turn white, seriously the plants becoming wilt and die. In this situation, it’s often misdiagnosed as bacterial angular leaf spot disease, which is particularly harmful to the cucumber plants
In addition, winter heating, inadequate fuel combustion will produce toxic gases, if ventilation not in the time it will cause the accumulation of carbon dioxide in a timely thus to affect the vegetable production.
Rational application of fertilizer Greenhouses applying organic fertilizer must pass through the heat of composting, quality fertilizer, urea should be mixed with calcium phosphate fertilizer. Basal to 20 cm deep, and depth of topdressing fertilizer up to 12 centimeters, and after that make timely watering.
Ventilation In warm weather should be combined with temperature regulation for ventilation, rain and snow should also be properly ventilated.
To choose safe and nontoxic agricultural film and ground cover cloth. Clear up the waste plastic products and residue in time.