Late blight is very annoying for gardeners in a rainy, cold period. Learn about the complex of measures for the prevention and control of this disease. Late blight in translation from Greek means "destroying", "destroying plants." It can infect nightshades (potatoes, tomatoes, to a lesser extent eggplants, peppers), as well as buckwheat, strawberries, castor oil plants.
What is this disease?
If the disease has struck a potato, then its pathogens can be spores that have remained overwintering on infected tubers in the ground, on the tops, in the soil. From potatoes, they quickly penetrate other crops, so it is important to remove plant residues after harvest, but not to compost them, but to dispose of them. After all, phytophthora spores do not lose their viability for several years and can damage the crops under which the same compost will be poured.
Late blight fungi develop when conditions are suitable for them - the air temperature rises above +10 ° C, and the air humidity of 75% and above is observed for more than two days. Fungal spores are located on foliage, settle on the trunk of a plant, and infect fruits. When it rains, it flushes the fungus into the soil, where it infects the potato tubers. Dark or gray patches appear on them, and under the skin they turn reddish brown. Healthy looking but infested tubers can rot later when in storage or in the store. And green tomatoes affected by late blight, ripening on a bush or indoors, will begin to darken.
The wind also contributes to the spread of late blight - it can carry spores for many kilometers. Fungus can also persist on garden tools, clothes. Therefore, it is necessary to observe hygiene, and at the end of the season, you need to disinfect the greenhouse, dig deep into the soil or remove its top layer, where the spores of the fungus have settled. This issue will be discussed in more detail below, but for now, check out the folk remedies that will help treat late blight at an early stage or prevent its occurrence.
Often, gardeners are worried about when late blight appears on tomatoes, therefore, further it will be told about this problem, measures to combat it, using various means. Potato tops can also be treated with similar solutions, and if the disease on potato bushes appeared at a later date, it is simply mowed and burned or thrown into the trash can.
How to deal with late blight on tomatoes - folk remedies
Kefir sprays are a prophylactic agent. To do this, you need to dilute 500 g of kefir in 5 liters of water, stir thoroughly. Two days before this, kefir must be taken out of the refrigerator and allowed to ferment. The first spraying is carried out 10-14 days after the seedlings are planted in the ground, then they are sprayed every 7-10 days.
Garlic will also help prevent and combat fungal spores. To prepare the product, you need to pass the garlic through a meat grinder to make half a glass of mass, put it in 5 liters of water and leave for a day. After that, strain, add 1 g of potassium permanganate, mix.
The first spraying is carried out before the formation of the ovary, and the second time they are treated in a similar way after 10 days. Then it is sprayed every 2 weeks.
Salt spraying promotes the formation of a biological film on the leaves and other parts of the plant, which will prevent fungal spores from penetrating to them. Half a glass of table salt is dissolved in 5 liters of water and processing is carried out.
Other methods of dealing with late blight
For the prevention of late blight, the use of biostimulants that increase immunity helps well. If the disease appears, then fungicides are used:
- "Tattu";
- Ridomil;
- "Quadris";
- "Acrobat MC" (one of the best tools).
To defeat late blight of tomatoes, first, before spraying, you need to remove the affected parts of the plant. Leaves that have dark spots are easiest to trim with scissors. To prevent the spread of spores, the tool must be periodically immersed in a solution of dark red potassium permanganate, preferably after processing each bush.
Late blight usually appears in late July or early August. Therefore, open field tomatoes must be harvested before this date. Fruits are light green in color with a glossy shiny surface, ripen at room temperature.
Tomato varieties are good or medium resistant to late blight
The correct selection of tomato varieties will also help prevent fruit death due to this disease. Here are interesting results of studies in which tomatoes were not treated with fungicides at all. According to the degree of resistance to late blight, the tested varieties were divided into 2 groups.
The first group includes tomato varieties on which there were almost no signs of disease, even without drug treatments. It:
- Donatos (has very large, round, dense fruits);
- Romoghetti (rounded red fruits);
- Bogdanovsky (stored for a long time);
- Vinetta (small fruits, good for canning, salads);
- Big girl (weighing up to 1 kg, heart-shaped);
- The giant is heavy (also some fruits reach a weight of 1 kg);
- Geisha (round, large, pink);
- Unique (weighing 150 g, red);
- Emerald apple (ripe green tomatoes);
- Gummy (round, one-dimensional);
- Fairy (tomatoes are light yellow);
- De Barao pink superior;
- Amber Cup (orange fruits);
- Long-term storage;
- Italian square;
- Healing.
The second group includes relatively resistant varieties of tomatoes, these are:
- Japanese crab;
- Pink flamingo;
- Sugar Giant;
- Big boy;
- Tsifomandra;
- Persimmon.
The difference between these varieties from the representatives of the first group is that their lower leaves are more susceptible to diseases. But as a result, the yield is almost the same as that of the first group of tomatoes.
The advantage of these varieties is that even rainy weather does not negatively affect their taste, while in other tomatoes such conditions lead to its deterioration.
Complex fight against late blight
A set of measures will help to defeat late blight of potatoes, tomatoes, and other nightshades. First of all, this is the choice of varieties that are resistant to this disease. It is better to grow seedlings yourself, then you can be sure that healthy seed is used. It is better to purchase planting potatoes in a specialized store or use your own. If you bought it on the market, before planting, place the tubers for 30 minutes in a solution of red potassium permanganate, in the preparation "Maxim" or another that has a similar disinfecting effect.
The planting site should be thoroughly cleared of plant debris in the fall of last year. Plant potatoes, tomatoes, eggplants, peppers, and strawberries in areas where these crops have not grown in the last 4 years. You need to place it at a sufficient distance so that the tops are well ventilated.
Seedlings must be periodically treated with folk or other drugs for late blight. After watering (always with warm water), the greenhouse must be ventilated. After the formation of the fruits of the tomatoes of the lower brush, all the leaves located below it must be removed. Stepsons need to be cut as soon as they appear. Tie up tomatoes in time, make sure that leaves, fruits and stems do not touch the ground.
When cold rainy weather sets in, sharply reduce the watering of nightshades in the greenhouse, if necessary, water them occasionally and only in the morning, and then open the doors to let the bushes ventilate. At night, on the contrary, the doors in the greenhouse must be tightly closed, like all the cracks, so that phytophthora spores do not penetrate inside. Disinfect the instrument. After harvesting, do not compost the nightshade tops, but destroy. Dig up the place where the potatoes grew, spill it with a solution of copper sulfate (100 g of this substance per 10 liters of water). If the tomatoes have been growing in the greenhouse for 2 years in a row, remove the top layer of the earth (7 cm), and dig the soil deeply. Also spill it with a solution of copper sulfate.
If the greenhouse is not removable, rinse the walls from the inside with a solution of soda (200 g per 10 liters of water) and rinse with a stream of water from a hose. At the end of its disinfection, set fire to the sulfur stick and leave it to burn out. For the winter, it is advisable to remove the greenhouse doors so that the frost will destroy the fungal infection. If you are in the country in winter, periodically throw snow inside the greenhouse.
If late blight appears on strawberries, after harvesting, mow the leaves, destroy them, treat the plants with one of the above drugs for late blight. Until October, new leaves will grow on it, and it will overwinter well.
Find out how to protect tomatoes from late blight from this video:
