Protection of tomatoes from phytophthora 

There is hardly a gardener who is not at all familiar with phytophthora. Unfortunately, anyone who has grown tomatoes at least once knows firsthand about this disease. Late blight is very dangerous, because it appears suddenly, but spreads very quickly – in a couple of days, the agrarian can lose all the plants if he does not take any measures.

How to protect tomatoes from late blight, what preventive measures to take, and what to do if tomatoes are already infected with a fungus – all this is in this article.

What is phytophthora and why is it dangerous

Late blight is a fungal disease that affects mainly plants from the nightshade group. Most often, potatoes are infected with this disease, and tomatoes suffer after it.

Translated from Latin, late blight means “devouring the harvest.” And this is true: at first, the fungus appears on the wrong side of the tomato leaves and looks like small brown spots, then the foliage turns black, dries out and falls off, then the phytophthora passes to inflorescences and fruits, and lastly it affects the stems of the bushes. As a result, tomatoes simply die, and almost ripened fruits become unsuitable for human consumption.

Today, more than a hundred species of phytophthora are known, any of them is very dangerous. The spores of the fungus that causes phytophthora are so tenacious that they can remain in any environment for up to three years:

• on tomato seeds;
• in the ground;
• in the remains of plants;
• on garden tools;
• on the walls of the greenhouse.

Phytophthora loves cool weather, lack of direct sunlight, poor access to fresh air, sudden changes in temperature and high humidity. To protect tomatoes from a dangerous disease, it is necessary to exclude all factors favorable for the development of phytophthora.

What causes phytophthora on tomatoes

There are many reasons for the infection of tomatoes with phytophthora. However, strong and healthy plants, which are properly cared for, which are fed in a timely manner and watered correctly, almost never get sick, including phytophthora, they are not dangerous.

And the peak of phytophthora occurs in August, when it is still very hot during the day, and it is already cool at night – as a result of which dew falls on the tomatoes.

The main task of the gardener is to prevent a combination of such factors. It is important to remember that phytophthora fungus will definitely appear when:

• tomatoes planted too close to potatoes or other nightshade plants;
• last year, nightshade crops grew on a plot with tomatoes, and late blight fungus spores remained in the ground;
• a constant high humidity is maintained on the site or in the greenhouse;
• the air temperature is too low;
• temperature jumps occur, which leads to dew on tomatoes, the appearance of fogs – all this contributes to an increase in humidity;
• tomatoes do not have enough sunlight, because the tomatoes are planted in the shade or their plantings are too dense;
• normal air circulation between tomato bushes is disturbed;
• tomatoes were fertilized too abundantly with nitrogen fertilizers;
• the soil in the area with tomatoes contains too much lime (acidic soils);
• knowingly infected seeds or seedlings of tomatoes are planted.

Prevention of late blight on tomatoes

Tomatoes are protected primarily by proper agricultural technology: compliance with planting patterns, fertilization, and watering. Agrotechnical measures directly depend on the method of growing tomatoes: in open ground or in a greenhouse, as well as on the variety and type of tomatoes: tall or determinant, early or late, resistant to fungal infections or not immune.

So far, there are no tomatoes that absolutely do not get sick with this infection, many tomato varieties have been bred with increased resistance to late blight.

The next step in the prevention of tomatoes from late blight is the proper processing of tomato seeds before planting on seedlings. To increase the immunity of the tomato and kill the fungal spores that may be on the seeds, the planting material is placed in a warm solution of potassium permanganate (pale pink) for 20-30 minutes. After treatment, tomato seeds are washed with running water and planted as usual.

How to protect tomatoes from phytophthora in open ground

The fight against phytophthora in garden beds consists in agrotechnical measures. So that the fungus does not have a chance, farmers are doing the following:

1. Deacidify soils with a high lime content. Peat is used as a neutralizer, which is scattered over the site and dig up the ground. This will help restore neutral acidity, phytophthora does not like such an environment.
2. During the transplantation of tomato seedlings, a handful of dry sand is poured into the holes, and tomatoes are planted in it.
3. For three years, they do not plant tomatoes in the place where onions, turnips, carrots, potatoes, cauliflower, cucumbers or beets used to grow – they observe crop rotation.
4. For tomatoes, choose the highest place on the site, it should be well lit by the sun throughout the day and properly ventilated. If the plot is low, it is recommended to make high beds for tomatoes.
5. Tomato seedlings are planted strictly according to the scheme developed by agronomists and indicated on the bag of seeds. In no case should tomato plantings be made too thick, this interferes with normal air circulation and obscures the plants.
6. Tomatoes are watered in the morning or late in the evening, when the sun’s rays no longer bake and cannot burn the leaves. Watering must be carried out strictly under the root of the tomato, making sure that the stems and leaves remain dry.
7. If there is enough rain in the region, the tomatoes are not watered at all, so as not to increase the already high humidity.
8. The ground between tomato bushes must be regularly loosened so that the roots of the plants can also be ventilated.
9. Fertilizers such as potassium and phosphorus are applied under tomatoes, which help strengthen the immunity of plants.
10. Control the amount of nitrogenous fertilizers in tomatoes, they should not be too much.

In addition to all the above safety measures, gardeners regularly inspect the tomatoes in the beds, turn the leaves over, and monitor the condition of the tomato stems. If late blight is detected at an early stage, there is a chance to save the crop.

The gardener must remember that initially late blight affects potatoes, and after him it is taken for tomatoes. That is why these two crops are forbidden to be planted side by side.

What to do to protect tomatoes in a greenhouse

A greenhouse is an excellent habitat for any infections, fungi of the genus Phytophthora are no exception. Mushroom spores love moisture and stale air, and in greenhouses this is more than enough.

If the greenhouse is new, the gardener has nothing to be afraid of – the likelihood of phytophthora in a closed, uninfected room is extremely small. But, when a greenhouse is reused, it must first be thoroughly disinfected.

Greenhouse cleaning is as follows:

• remove the web;
• wash the film or glass with a disinfectant;
• remove the remains of last year’s plants;
• change soil.

Agrotechnics of greenhouse tomatoes is as follows:

1. Before planting, tomato seedlings are dusted with a mixture of tobacco dust and wood ash. This composition is prepared from two glasses of dust and a bucket of wood ash. Tomatoes should be handled with goggles and a mask.
2. The walls of the greenhouse are treated with one of the disinfectants: Baikal, Fitosporin, Radiance or others.
3. It is better to water greenhouse tomatoes by drip method, using only warm water. So, moisture will come in small doses directly under the root of the plants.
4. A greenhouse with tomatoes should be ventilated frequently by opening windows and doors.
5. There should be no condensation on the walls of the greenhouse, if moisture accumulates, it is wiped with a dry cloth.
6. Carry out preventive treatment of tomatoes at least three times per season.

Means of combating phytophthora

It is necessary to process tomatoes for the prevention of phytophthora at least three times per season. They do it according to the following schedule:

1. 7-10 days after the tomato seedlings were planted in a permanent place, and the tomatoes began to grow, that is, they took root in a new place.
2. Just before the first flowers appear.
3. Before the formation of the ovaries of tomatoes.

This schedule is only suitable for preventive treatments, if the tomatoes are still infected with late blight, the treatment should be carried out in accordance with the instructions for the selected drug.

Phytophthora can be fought against both with purchased chemicals and folk remedies. Moreover, the former are more effective, but the latter will not harm either the plant itself or the person, since they are non-toxic and do not accumulate in tomato fruits.

It is necessary to treat late blight of tomatoes with fungicides – drugs that fight fungi. Gardeners most often use the following tools:

• Fundazol;
• Quadris;
• Trichopolum;
• Phytosporin;
• Previkur;
• Horus;
• Thiovit.

In addition to special narrowly targeted means, late blight is fought with Bordeaux mixture, copper oxychloride, and copper sulphate. All substances are diluted with water in accordance with the manufacturer’s instructions. Usually, apply fungicidal preparations to tomatoes by spraying, irrigating the tomato bushes with a mixture.

To date, there are a lot of antifungal drugs for tomatoes, but the active ingredient in them is usually the same. Because of this there is a quick addiction to the drug, if it was not possible to overcome the phytophthora of tomatoes in one or two times, you will have to resort to folk remedies – chemistry is already powerless.

Folk methods

Folk remedies are used more often, as they are harmless, cheap and give good results.

There are many folk ways to deal with late blight of tomatoes, the most popular among the population are such means:

1. Sour milk whey. Serum is bought in a store or prepared independently on the basis of kefir. To prepare a medicine for a tomato, the serum must be diluted with water in a 1: 1 ratio. Starting from the first days of July, you can spray tomato bushes at least daily (depending on the condition of the plants).
2. Tincture of garlic is also a strong remedy against late blight of tomatoes. To prepare the composition, they take not only cloves of garlic, but also greens, arrows, any part of the plant. All this is carefully crushed (you can twist it in a meat grinder), pour it with water and leave it for a day. After 24 hours, drain the liquid, filter and dilute with clean water. For greater effect, you can add potassium permanganate to the same composition (about 1 gram). The solution is irrigated with tomato bushes.
3. wood ash it is good to use as a primary treatment of tomatoes – 10 days after planting seedlings in the ground. The ground between the tomatoes is sprinkled with a thin layer of ash and watered with warm water. Processing can be repeated during the flowering period of the tomato.
4. Rotten hay or straw are also a good remedy for late blight of tomatoes. The tincture is prepared as follows: a kilogram of hay is poured into a bucket of water (10 liters), a little urea is added there, and the liquid is left to infuse for 3-4 days. Then the solution is filtered and tomato bushes are treated with an interval of two weeks.
5. iodine you can also process tomatoes, because it is known as a strong antiseptic. To prepare the solution, take a bucket of water, a liter of fresh, but low-fat cow’s milk and 15-20 drops of iodine. Fresh composition should be sprayed on tomato bushes, repeat the treatment every two weeks.

The salt film on the tomatoes will prevent the development of the fungus, the tomatoes will be able to ripen normally.

Results

Fighting late blight of tomatoes is much more difficult than preventing this disease. Therefore, all the forces of the agrarian should be directed to preventive measures – the prevention of infection of the tomato. In order to save tomatoes, it is necessary to observe the agricultural technology of the culture, to try to identify bushes infected with late blight at a very early stage.

For an effective fight, the gardener must use combined means: alternate chemicals with folk antifungal compounds. Watering tomato bushes too often is not recommended, as this can increase the humidity and further aggravate the disease. The ideal interval for processing tomatoes from late blight is 10-14 days.