A Detailed Guide to Common Types of Gas Damage in Greenhouses and Their Prevention and Control Methods
In winter and spring, because it is relatively low, the ventilation inside the greenhouse is poor, and in addition ventilation cannot be carried out in time, causing harmful gases inside the greenhouse to continuously accumulate, resulting in gas damage to the crops in the greenhouse, ranging from yellowing leaves and dried tips in mild cases to the death of the entire plant in severe cases. So what are the common types of gas damage? How should they be prevented and controlled? Follow the editor to learn about them.
1. Ammonia gas and nitrous acid
These two types of gas damage are mostly caused by improper fertilization. For example, when ammonium bicarbonate is applied or a large amount of urea and undecomposed organic fertilizer is applied during topdressing, combined with high temperature, drought, and poor ventilation, a large amount of ammonia gas and nitrous acid gas is often produced in a short time, causing plant poisoning. It often manifests as water-soaked spots on the leaf margins, as if scalded by boiling water, or gradually turning brown, drying up, and falling off.
Prevention and control methods: When topdressing in the greenhouse, avoid using ammonium bicarbonate, urea, and ammonium sulfate. Farmyard manure and organic fertilizer must be fully decomposed before being applied.
2. Carbon monoxide and chlorine dioxide
When coal or charcoal fire is used for heating in the greenhouse, because of incomplete combustion or poor flue ventilation, a large amount of carbon monoxide and sulfur monoxide is produced. When crops are harmed by these two types of gas damage, the leaf veins first show spotted white or yellow patches, and in severe cases the entire leaf becomes a green net-like skeleton, then slowly dies.
Prevention and control methods: For greenhouse heating, use electric heaters as much as possible, and use traditional heating methods as little as possible. Even if they must be used, be sure to use low-sulfur combustion materials, and also ensure safety.
⟦NL>3. Toxic gas released by film
Some plastic films have plasticizers and stabilizers added during the production process, and during use they release toxic gases such as ethylene and chlorine as well as harmful substances such as diisobutyl phthalate. When these gas damage occurs, it causes light brown irregular spots on the leaves, and in severe cases the leaves turn white or even fall off, and it also causes the leaf tips and leaf margins of flowers to turn yellow, or even turn white and dry up.
Prevention and control methods: Ventilate and exchange air in time. Open the ventilation openings at noon on sunny days. Even on cloudy, rainy, or snowy days, carry out short periods of ventilation and air exchange to minimize the harm of toxic gases.
4. Excessive pesticide use
When pesticides or fumigants are used excessively, or when fumigants are used reasonably, such as formalin and methyl bromide, which can only be used in empty greenhouses, using them during the plant growing season easily causes pesticide damage. All of these cause phenomena such as leaf yellowing and dried tips in plants.
Prevention and control methods: The use of pesticides must be scientific and reasonable, and must never be used carelessly. This is the main measure to avoid pesticide damage causing gas damage.
The above is an introduction to the common types of gas damage in greenhouses and their prevention and control methods. I hope it can help you. To learn more related knowledge, please follow us.