Why is tomato anthracnose dangerous and how to treat it?

Tomato anthracnose is a fungal disease that can kill already mature plants along with the fruits. Even a mild lesion, when only 1–2 leaves and their petioles were affected, leads to a decrease in yield by 45–50%. The earlier treatment is started, the less losses will be. Better yet, get started with prevention.

Sources of infection and conditions for the development of the disease

The causative agents of anthracnose are spores of ascomycete fungi. Favorable conditions for their development are high humidity (about 90%) and warmth (above +22 ° C). It is not surprising that the disease affects tomatoes mainly in greenhouses, and in the open field it develops only in rainy years.

The most obvious sources of tomato contamination are:

• Seeds. Microscopic spores transfer to their surface from diseased fetuses.
• Last year's tops, fallen leaves and other plant debris not harvested in the fall. Whole myceliums winter here with many spores inside.

In addition, fungi can inhabit lumps of earth, weeds, garters, pegs, and in a greenhouse - on any of its inner surfaces (walls, trellises, racks, etc.).

Signs of tomato infestation

Fungal spores are transferred from the focus of infection to healthy tomato bushes, settle on leaves, in drops of dew, rain or remaining after watering. Once in a favorable environment (warm and damp), they begin to actively develop:

1. Spores germinate in leaf tissue, pump out juices and release poisonous products of their vital activity instead.
2. As a result, dark spots appear on the leaves in the affected areas, sometimes with an orange or pink tint, framed by a purple border.
3. The spots grow over time, merge with each other.
4. The entire leaf turns brown, dries up and falls off.
5. Tomato anthracnose affects the entire plant, including stems and roots.

Since this disease manifests itself in late summer and autumn, when most of the leaves have already been removed or, in our opinion, the tops are already turning yellow, we often notice signs of anthracnose on ripening tomatoes. On their surface, softening is first found of the same color as on the leaves. Then depressed spots appear in these places. They darken and turn black. At the last stage, the fruits are mummified - wrinkle and dry out.

If the spores of the fungi were on the surface of the seeds, then the seedlings are affected. And in the garden bed from plant residues or poorly rotted compost, fungi move to adult bushes and fruits. The most annoying thing is when we collect poured and, at first glance, healthy fruits, and they rot during ripening. Infection with the fungus occurs even in the garden, the tomatoes of the lower brushes, growing close to the ground, touching it, are especially affected.

How to protect seedlings from disease?

Seedlings will be healthy if, before sowing, you disinfect not only the seeds, but also the soil. Do not forget that fungi can live in unripe compost or humus, which are often added to soil mixtures.

Prevention and treatment of anthracnose on seedlings:

1. Soak the seeds for 20 minutes in a pink solution of potassium permanganate, then rinse them in clean water and dry them before sowing. Also, gardeners use hydrogen peroxide from the pharmacy for disinfection. Alternatively, spread the seeds on a cotton pad and pour over boiling water from a kettle. Throw in as much water as the cotton ball can absorb. The seeds should only be scalded and not floated in boiling water.
2. Pour the soil with boiling water or heat it in any way possible to 100 ° C. It is better to do this in the fresh air, on the grill, since the process is accompanied by an unpleasant suffocating odor.
3. Pour the cooled soil with a solution of "Fitosporin" (1-2 tablespoons of working concentrate from the paste per 10 liters of water). So you will populate the sterile soil with beneficial bacteria, which, with the possible appearance of pathogenic fungi, will compete with them for their habitat, food, and thereby destroy most of them.
4. When characteristic spots appear on the seedlings, spray with a fungicide: HOM, 1% Bordeaux liquid, "Skor" and the like. The treatment must be repeated after 10 days.

Buy hybrid seeds marked F1 on the packaging, they are almost all resistant to fungal diseases. But tomatoes grown from their own seeds are often affected by anthracnose, especially when kept on poorly ventilated window sills and in greenhouses.

How to prevent and treat anthracnose in the garden?

If your tomatoes were sick with anthracnose last year, then there is a high probability of infection this year. There is also a risk when buying seedlings in the market and even in the store. Diseased plants can be shared with you by neighbors and relatives. And if there is a focus of infection in a greenhouse or in an open-air garden bed, then even the most disease-resistant hybrids may suffer under favorable conditions for anthracnose.

Prevention of anthracnose after disembarkation:

• Harvest the tops in the compost heap in the fall, and discard the infected.
• Observe the crop rotation, do not plant tomatoes in the same place every year.
• In the greenhouse, change the top 20–30 cm of the ground, or immediately after the tomatoes, sow green manure beds (phacelia, mustard), and also grow them in the spring, before planting seedlings.
• Before planting, spill the earth with hot water, a solution of potassium permanganate, copper sulfate (1 tablespoon per 10 liters of water) or other copper-containing agent. In the greenhouse and greenhouse, treat all internal surfaces with a fungicide (HOM, "Skor", "Ordan", etc.).
• A week after planting the seedlings, when it will take root and grow, spray the bushes and the ground under them with one of the above fungicides for prevention.
• Water strictly to the root so that water drops do not linger on the leaves.
• Do not overuse foliar dressing. Do them only on a fine day, preferably in the morning or a few hours before sunset, so that the leaves are already dry by night.
• Use growth stimulants as foliar dressing: Novosil, Energen, Epin, HB-101, etc. They will strengthen the immunity of tomatoes.
• Remove the leaves underneath as the brushes mature.
• If you have undersized varieties, tomatoes are on the ground, then place planks or dry mulch under them.

At the first sign of anthracnose, tear off any stained leaves and burn them. Spray the bushes with a solution of "Fitosporin" - this is a biological product harmless to our health.

If there is still about a month before harvesting, then more effective chemical agents can be used: a copper-containing fungicide or a solution of colloidal sulfur (20–40 g per 10 l of water).

Bushes severely affected by the disease, uproot and, along with the fruits, take them from the site to the trash can.

How to prevent crop spoilage?

Do not overexpose tomatoes on bushes, do not let them overripe and crack. For transportation, storage and ripening, collect in blanche ripeness, when the tops are just beginning to blush. Protect tomatoes from mechanical damage during transportation. The slightest crack with leaking juice is a favorable environment for the consolidation and development of anthracnose spores.

Store tomatoes at a temperature not exceeding +6 ° C. The room must be dry to prevent condensation from falling on the tomatoes. Add also in a dry, but warm place - from +15 ° C.

Tomato anthracnose, like any fungal disease, is easier to prevent than to cure.Grow only proven and disease resistant varieties.

Take good care of your tomatoes:

• feed;
• stepchild;
• water on time;
• rid the beds of weeds in time;
• use growth stimulants.

Strong and sturdy tomatoes with good immunity are better able to resist diseases and are less affected by them than frail, thickened plants lacking nutrition and moisture.