Autumn disinfection of greenhouses significantly reduces the likelihood of damage to plants next summer by diseases and pests. Such work should be carried out at the end of September at an air temperature of at least 8 degrees. Such disinfection can be gas or wet.
Gas disinfection of glazed wooden greenhouses requires a good greenhouse tightness. It is fumigated with sulfur at the rate of 50-80 g of sulfur per 1 cubic meter of greenhouse volume. If the greenhouse was affected by a spider mite, then the dosage is increased to 150 g per 1 cubic meter.
Before burning sulfur, all the cracks in the greenhouse are carefully covered. Sulfur is burned on baking trays filled with burning coals. Baking trays are placed on bricks in different places in the greenhouse. When the sulfur lights up, you need to close the door tightly and keep the greenhouse closed for three days, after which it should be well ventilated. For safety, such disinfection should be done only in a gas mask, in extreme cases - in a respirator.
Glazed metal greenhouses should not be fumigated with sulfur dioxide, because this destroys the protective film that protects the metal from destruction.
Much more accessible is wet disinfection - abundant spraying of the greenhouse from the inside and the entire soil with a solution of bleach infused for 3-4 hours (400 g of lime per 10 liters of water). The spray liquid is carefully drained and the sediment is used to brush over the wooden parts of the greenhouse with a wash brush. If there was a spider mite in the greenhouse, then the amount of bleach is increased to 1 kg per 10 liters of water.
You can also use 40% formalin (250 g per 10 L of water) to disinfect the greenhouse. But due to the toxicity of formaldehyde released from it into the air, this operation should be carried out in a gas mask.
Simultaneously with the chemical treatment of the greenhouse, it is necessary to mechanically destroy mosses and lichens on the logs at the base of the greenhouse in it and treat all wooden surfaces in the greenhouse with a 5% solution of ferrous sulfate to destroy their spores.
The soil from the greenhouse and greenhouse is often a breeding ground for the most dangerous diseases and pests for cucumbers, tomatoes and cabbage. Therefore, it also needs to be either replaced in the greenhouse or disinfected. To do this, "healthy" soil is taken out of the greenhouse and used to form open ground vegetable ridges and to fertilize shrubs. And if the soil requires "treatment" for diseases and pests, then it is piled up, sprinkled layer by layer with dry bleach (250 g of bleach per 1 square meter of the stack with a layer of 20 cm) and left for the winter to freeze.
Good results are obtained by disinfecting the soil with carbation. This drug is a 36-40% aqueous solution of sodium salt of monomethyldithiocarbamic acid. The contaminated soil is watered with this solution while shoveling. For 1 cubic meter m of soil consume 400 g of carbation per 10 liters of water. Carbation is used in the fall, after harvesting plant residues. The soil temperature should be at least 10 ° С, and the air temperature - 18 ° С. When working with carbation, they use a gas mask, a rubber apron, boots and gloves, and after work they thoroughly wash their hands and face with soap.
If your land in a greenhouse is infected with late blight, black leg, nematodes, ticks, then this land from a stack in the spring should not be used in the greenhouse. In the summer, it must be shoveled again and only used again after a year.