Tomatoes are a unique plant. A variety of varieties makes garden work a pleasure. There are varieties with vertical branches and with vines, with yellow, brown, red fruits, oversized and compact. Surely a tomato empire may one day be created. But it should be remembered that for the agricultural industry, private farming and horticulture, late blight is a particular danger. Tomatoes can fall ill with them in the summer, growing in open ground, a greenhouse, and even in winter in heated ones. Most often, it appears in August or after rains.
Symptoms of late blight on tomatoes
The development of the disease begins with the aerial parts of tomatoes. The color of the lower branches or the upper branches changes, depending on how the infection occurred. Mushroom spores can fly into the garden with the wind, or they can wake up, arriving for a long time in the ground.
Brown areas on the stems indicate that they joined the plant cells, absorb its juice. It soon turns out that all branches are already infected. Irregular-shaped yellow spots appear on the leaves. They are deformed, dry in the places of damage, twist.
If the fruits have already formed at this point, damaged, putrefactive patches of black, brown or yellow color also appear on them. Unripe tomatoes stop growing.
Biological features of late blight
The causative agent of late blight on tomatoes is a fungus belonging to the genus late blight. More precisely, oomycete is a mycelial organism, which is very similar in structure to fungi, but has a number of differences. It is believed that oomycetes appeared on Earth earlier than mushrooms and theoretically they can be distinguished into a special group.
This microorganism is called late blight infestans (Phytophthora infestans). It can infect both tomatoes and potatoes, eggplant, sweet and bitter peppers. His homeland is Mexico. Gradually, it spread throughout the world. Now, cases of late blight are regularly recorded in different countries, in all corners of the Earth. Its other varieties are dangerous for crops and herbs. They also significantly harm the agricultural industry. The phytophthora infestan is dangerous by the speed of spread, as well as resistance to negative environmental factors.
Disputes can remain in the ground for several years, withstand frost and heat, drought. They can settle in compost, on rotten logs, not only on garden crops. They can infect garden tools. As soon as environmental conditions change, they become favorable again, plants become infected.
The main differences from the simplest mushrooms:
- cell membranes are coated not with chitin, as is the case with fungi, but with cellulose - that is, they are less resistant to mechanical damage;
- the vultures are not separated by partitions; they are a simpler substructure in structure;
- a population cannot develop outside host cells.
This makes them more vulnerable at first glance. In fact, the opposite is true. If they were infected tomatoes harvested in August, hidden in the cellar for a couple of days, soon the entire crop sent to storage may become covered with putrefactive stains. The same goes for potatoes. In the tubers of this culture, they can go unnoticed for a long time.
Favorable environmental conditions for the development of late blight infestan are:
rains for several days in a row;
- dampness;
- windy weather;
- cooling.
It is necessary to inspect the plants in this case. Of course, not every season the disease reminds of itself. But one day he will probably have to fight. This is inevitable if crops grow on the site, the juice of which this mushroom likes. In danger are all nightshade, very popular in horticulture, popular crops.
How to deal with late blight on tomatoes
Experts recommend giving preference to prevention, trying to prevent infection. This is beneficial from many points of view:
- the cost of drugs is low;
- they are stored on average 2-3 years, that is, they can be used for the next season;
- they are universal, protect against many diseases, not only from late blight;
- effective - the chances of success increase many times.
Most of them are bio-fungicides that are safe for health. Fitosporin, Fundazole and analogues, endowed with different features, are popular.
There are great folk ways to fight. The siderate method helps. This is for open ground. To avoid infection in the greenhouse, you need to observe the temperature regime and do preventive treatments with the same drugs.
Fitosporin
Bio-fungicide Fitosporin is intended for the prevention and treatment of a variety of fungal and bacterial diseases of plants, tomatoes, in particular late blight. It contains hay bacillus (Bacillus subtilis), which is a natural enemy of these parasitic species. It stops their distribution, improves the condition of the soil in the garden.
With it, you can protect tomatoes from the very first day, when germinating from seeds at home, during transplantation into the open ground and at the time of infection by spores. They cultivate the aisle, soil at the roots of tomatoes, garden tools, dry tops left for compost. The risk of the mushroom attacking again after a month or next season is minimized. After spraying, a film is created on the leaves, branches, which protects the culture. After a week, it is advisable to re-treat.
It is allowed to regularly water the beds with a solution of the drug, once a month. Spraying foliage so often is not necessary. Only if the weather has worsened, does it make sense to hedge
. It is convenient to use Fitosporin due to the fact that you can buy it in the form of a concentrated solution, powder or paste. The hazard level of this product is medium (grade 4).
Fundazole
Fundazole affects in the same way, but it has a different composition. The main active ingredient is benomyl. It acts on the spores of fungi, prevents the division of their cells, reproduction. With prophylactic use, it reduces the likelihood of their penetration into plant tissues. In other words, strengthens the immunity of plants. Helps fight ticks and aphids, unlike Fitosporin. It is not effective at the same time against diseases of a bacterial nature. It is attributed to slightly hazardous drugs (hazard class 3).
Blue vitriol
A universal and inexpensive tool is copper sulfate. The main active ingredient is copper sulfate. It is an antimicrobial and antifungal agent. Practice shows that in the case of late blight, it is very effective.
The advantage of copper sulfate is a wide scope:
- It is needed to care for other crops, not just tomatoes.
- Helps to quickly get rid of late blight, settled on plants, and spores in the soil.
- An environment is created that is not suitable for their survival.
- Belongs to substances of little danger (3rd class).
It is partly a fertilizer for tomatoes due to its copper content. Copper starvation leads to a violation of the vital functions of cells. Ovaries, fruits do not form, foliage becomes brown. Vitriol improves growth, regeneration, photosynthesis. This immediately becomes noticeable. The least of it is in peaty soil. Especially relevant is its use as one of the fertilizers in this case.
In addition to chemicals, biofungicides, there are other ways to protect a tomato plantation from late blight. Good results are given by the use of siderates.
Siderata for the prevention of late blight
Siderates saturate the soil with nitrogen, accumulating it from the air. Other crops will impoverish the garden, and these will enrich. They do not cancel fertilizers. Apply bait is still worth it. Siderates prevent the conversion of nutrients into forms that are not absorbed by plants.
They improve air exchange thanks to a developed root system. Actively build up green biomass, in which there are many useful substances. This is a reliable protection against phytophthora spores. In particular, white mustard, oil radish, rapeseed, and phacelia are used.
Oil radish
The root system of radish oil functions in a special way. Substances attractive to bacteria are accumulated in the ground. These bacteria are found everywhere in the soil. They have a disinfecting effect, inhibit the development of the fungus. With a radish, symbiotic relationships are formed. All season tomatoes will be under reliable protection if this species grows nearby. The likelihood of infection is sharply reduced. A lot of essential oils with disinfecting properties accumulate in the foliage. All this makes it a great green fertilizer.
White mustard
Mustard exudes a scent that repels Colorado beetles. In addition, it synthesizes volatile, strengthening the immunity of tomatoes. In its roots, the elements necessary for suppressing the activity of spores accumulate.
Phacelia
Phacelia stops soil acidification reactions, which is generally beneficial. The level of fertility increases due to the fact that beneficial substances pass into an easily digestible form. This flower has proven itself as a biofertilizer, is actively used in the United States and European countries. In Russia, the most popular variety is tansy tansy. All its subspecies are excellent protection against phytophthora spores. Experts recommend combining the method of biofertilizer, green manure with mulching.
Rape
Another useful plant used as siderate is rapeseed. It also exhibits an antifungal effect. Essential oils accumulate in its leaves, stems, as in the oil radish.
Phytophthora resistant varieties
There are varieties of tomatoes with natural resistance to phytosporosis. It is easy to choose the most suitable option for the greenhouse or garden beds. Among them there are giant varieties, with massive branches and miniature, compact. The shape of the fruit can be fantastically beautiful or very practical. They will bring confusion if you already have a favorite variety. Become the wind of change. They will allow you to take a break from stereotypes.
These include:
- Tomato Top Ten. A short hybrid with exotic yellow fruits, early ripening. Used for the preparation of salads, in canning, has a great taste.
- Grape Mid-season variety with small red tomatoes, bush height up to 2 m. The bunches are spectacular, reminiscent of an ear.
- Lady fingers. A very popular option. Tomatoes are like berries. The bush is undersized. Belongs to unpretentious grades.
- Diet healthy man. The original variety with orange large fruits, branches up to 1.5 m in height. High-yielding, early ripe.
- Zhigalo. The height of the bush is up to 0.5 m. The color of the fruit is red.
- Avson. The bush is miniature. Does not need to be tied up. It grows in height no more than 45 cm. The fruits are small, red in color, ripen 95-100 days after planting.
- Compact Kakadu variety with large red fruits, early harvest.
- Leningrad precocious. Fruits in 85-100 days after completion of planting. Tomatoes are small, red, juicy.
Many other varieties have a high level of resistance to late blight. Choosing one of them, you can forget about this trouble. However, if a potato or other crop that is attractive to a harmful microorganism grows nearby, problems still cannot be avoided. The tomato plantation will survive, no potato.
It is important to carry out preventive spraying in a timely manner. Cut infected leaves, tubers, rhizomes must be burned, and compost treated with copper sulphate or similar preparations. It is advisable to grow companion plants nearby, siderata. The food supply is needed by the country and every family. Tomatoes are one of the main foods in the human diet. These measures will save you from losses, unnecessary expenses.
