Phytophthora is a scary word for agronomists, gardeners and gardeners. This is a very dangerous disease affecting the nightshade and some other cultivated plants, such as strawberries or cucumbers. As a rule, plants infected with late blight are not treatable, the only way out is to destroy them.
Late blight: danger of fungal disease
Phytophthora is a fungal disease affecting plants even in a polycarbonate greenhouse. Just like any fungus, a late blight spore consists of mycelium, conidia, and sporangia. The appearance of the mycelium resembles a white spider web. As a rule, it lives and develops in plant tissues. The reproduction of fungi is carried out with the help of spores formed in sporangia. After the spore has matured, the sporangia shell breaks, releasing the spores out. After that, they spread along with water, falling on plants, where the new life cycle of phytophthora begins. Spores of phytophtora are not afraid of even severe frosts. The active development of the dispute begins after the temperature rises to 10 degrees Celsius. 
The first sign of late blight is the appearance of brown spots on the stems and leaves of plants. At high humidity, the inner part of the leaves is covered with white bloom. Young tubers of potatoes and tomatoes, affected by late blight, become covered with dark indented spots, and the skin becomes fragile. It is through the skin that the plant becomes even more infected, at the same time spreading the disease to neighboring plants. If timely processing of tomatoes from phytophtora is not performed, the fruit tissues quickly rot and decompose, giving off a rather unpleasant smell.
Often, gardeners in an attempt to at least partially save the crop, tearing off the green fruit and hiding them for ripening. But along with the infected fruits, the phytophtora fungi fall into the box and after a while hit all the other fruits.
Did you know? Potatoes and tomatoes are affected by the mushrooms of the species Phytophthora infestans, which literally translates from Latin as “destroying the plants”.
How to process greenhouse from phytophthora
Preparation for the new planting season is made in the autumn, immediately after harvest. In the greenhouse, especially from polycarbonate, the likelihood that the spores of the phytophthora will persist in the upper soil layer, on plant residues or greenhouse construction elements, is very high. Therefore, when growing plants in greenhouse conditions, it is imperative to carry out processing from phytophthora. In this case, you will not think about how to save tomatoes from phytophtoras, but where to put the entire harvest.
Thorough disinfection of the greenhouse will allow to destroy the phytophthora disputes, as well as prevent the occurrence of the disease in the future. It is conditionally possible to divide the processing means from the phytophtora into:
- biological;
- chemical;
- temperature.
Cleaning greenhouses from plant residues and additional materials
Before disinfecting the soil from phytophthora chemicals, it is necessary to clean it from plant residues: tops, missing fruits, roots and weeds.
You also need to clean the greenhouse from the old twine and trellis.
Even if the plants did not hurt, due to the high concentration of plantings, they still left a large number of different pathogens. That is why the processing of polycarbonate greenhouses must necessarily be accompanied by the burning of all residues of plants and other materials. If you do not do this, then after winter all the microbes become more active and will begin to infect young plants.
Important! If the blight still “went through” the tomatoes and potatoes, then along with the destruction of plant residues, you must disinfect all garden tools.
Greenhouse Disinfection and Treatment
Processing greenhouses from phytophthora allows you to save plants and get a good harvest. The greenhouse can be made of glazed window frames, polycarbonate, or from conventional film. Before proceeding with gas disinfection, it is necessary to check the tightness of the greenhouse design and cover all the gaps. All disinfection works are carried out at a temperature not lower than 10 degrees Celsius. When disinfecting, the greenhouse is fumigated with sulfur or lump sulfur checkers. The average dosage is 50-80 g of sulfur per cubic meter; when infected with a spider mite, the dose increases to 150 g. In order to increase the toxicity of the fungicide, it is recommended to spray all surfaces of the greenhouse with water beforehand. 
Processing of the greenhouse from polycarbonate in the spring from phytophtoras is carried out necessarily in a respirator or in a gas mask. The greenhouse needs to be fumigated with the gray burning on the trays, which are placed along the perimeter of the structure. After sulfur lights up, the greenhouse closes tightly for three days. After this period, the greenhouse must be thoroughly aired.
Unfortunately, this method is not suitable for metal greenhouses, because sulfur pretty quickly eats away a protective layer of metal. Therefore, in such greenhouses resort to wet disinfection. The essence of this procedure lies in the abundant spraying of a solution of bleach on all surfaces of the greenhouse, including the soil. To prepare the solution, 400 g of lime should be diluted in a bucket of water and let it brew for 4 hours. You can also use a solution of copper sulfate (75 g of the substance diluted in a bucket of water).
Before processing the greenhouse in the spring from the phytophthora, especially if its frame is made of wood, it is necessary to wipe the structural elements a solution of fresh lime with the addition of vitriol. This will protect the tree and add light to the greenhouse. Also, along with chemical treatment, you need to destroy all the moss and lichens that have grown over the summer on the frame of the greenhouse.
After the disinfection is carried out, it is necessary to thoroughly wash all glass surfaces of the greenhouse. To do this, a weak solution of any kitchen cleaner that is applied to the surface with a sprayer is suitable. After that, it remains only to wipe the glass with a nylon brush and rinse it with clean water.
Did you know? Late blight was one of the reasons for the great famine in Ireland in 1845-1849. Due to starvation, the country's population declined by a quarter in just a few years.
Soil treatment in the greenhouse
Upon completion of disinfection procedures, care must be taken of how to treat the land after the phytophthora. It is necessary to thoroughly dig up the top layer of soil and be sure to fertilize it with humus, peat, manure, based on the calculation of half a bucket per square meter.
If you do not know how to treat tomatoes from phytophthora, then for complex protection it will be suitable sand ash mix, which fall asleep beds. Also for disinfection of soil can be used an aqueous solution of the fumigant "Carbation". It is recommended to use when digging the soil, when the temperature of the soil is 10 degrees Celsius.
Winter airing greenhouses
Winter is a serious test for plants, because low temperatures can be very harmful for future crops. Winter airing of the greenhouse plays a large role in the question of how to properly protect tomatoes from phytophtoras. Of course, if the greenhouse is heated in winter, then you can not worry about negative temperatures.
But heat for plants is not everything. Plants need to breathe, but as a rule, in the fall, the greenhouse is very tightly plugged to minimize the effects of low temperatures. As a result, the oxygen level becomes minimal. The only way out is the organization of ventilation, thanks to which oxygen will be supplied in sufficient quantity to the greenhouse.
When wintering the greenhouse, it should be assumed that at least 20% of the greenhouse is ventilated.
If this is ignored, then inside the greenhouse will stagnate moist air, which is an ideal environment for the development of late blight.
Important! The interval for ventilation of the greenhouse in winter should be 5-10 minutes.
How to cure phytophthora of tomatoes in the greenhouse
The question of when and how to process tomatoes from phytophtoras depends on many factors: the size of the greenhouse, the type of vegetable crop, the season and so on. Remember the main thing - you should not often use products containing copper, because it can be deposited in the ripening crop. Instead, it’s better to resort to popular methods, among which:
- Garlic infusion. This tool is extremely well established among experienced gardeners. To make it, you need to grind one and a half cups of peeled garlic, add half a teaspoon of potassium permanganate and pour two liters of water. After that, you need to cover with a lid and let it brew for 30 minutes, and then dilute with 10 liters of water. Consumption is based on the calculation of 0.5 liters of garlic solution for each bush.
- Water with iodine. Iodine from phytophthora in the greenhouse has a disinfecting effect on plants. To prepare a solution, dilute 10 ml of ordinary 5% iodine in a bucket of water. Before use, remove all yellowed leaves and leaves with dark spots. Spray the bushes and fruits with this solution, and after 3 days the procedure is recommended to be repeated.
- Serum or milk solution. Dilute 100 ml of milk in one liter of water, then spray the tomatoes with this solution. Also, milk can be replaced by kefir. Lactic acid bacteria contained in dairy products do not allow phytophthora to develop. To enhance the effect in the milk solution, you can add a few drops of iodine. Spraying with this solution protects against phytophthora, and also fertilizes the soil and plants. The interval between spraying should be 2 weeks. If the phytophthora appeared on tomatoes in the greenhouse and you do not know how to deal with it, then try sprinkling the plants with a solution of serum. It is diluted with water in a ratio of 1 to 1 and has the same effect as the milk solution. Plants are treated with this solution throughout the summer period.
- Salt solution. It is necessary to take regular table salt and dilute one cup in proportion to a bucket of water. This solution protects plants from various diseases, and after drying forms a protective film on the fruit.
Did you know? Many residents of Ireland emigrated from the country, trying to escape from the great famine of 1845-1849, caused by blight. Mortality on the ships carrying refugees reached 20-30%. Because of this, the ship was called "coffin-ship", which means "ship-coffin".
Phytophthora in the greenhouse: preventive actions
Plants grown in greenhouse conditions have the advantage of protecting against phytophthora compared to plants grown in open ground. In the greenhouse creates its own microclimate, which can be adjusted regardless of whether it is cold or damp outside. In order for you not to wonder how to save tomatoes from phytophthora in the greenhouse, follow simple rules for the prevention of late blight:
- mulch the soil;
- do not thicken landing;
- tie up bushes;
- Carefully pick off stepchildren and extra leaves.
Important! It is best to conduct late blight prevention in dry and calm weather.Phytophthora is a dangerous disease that can make the whole crop of tomatoes unfit for consumption, which is why control measures against it are so important. Conduct regular preventive measures against the occurrence of late blight and remember: the more resistant the plant, the more difficult it will be to hit the disease.
