Options for dealing with black spots on tomatoes

Main causes of blackening

Many gardeners are interested in the question - what are these black spots on tomatoes and how to deal with them. Experienced gardeners say that this problem can arise for several reasons, among the most common are:

• Late blight. The main symptom is blackened tomatoes. This blackness is caused by the spread of fungus.
• Gray rot. Occurs due to a fungal disease.
• Alternaria blight. Dry brown spots appear on tomatoes caused by a parasitic fungus.
• Dry soil. If you do not water your tomato bushes regularly, blackening may also occur.
• Stem necrosis. The main symptom is the formation of cracks in the lower part of the stem. Caused by viruses.
• Lack of care. With insufficient fertilizer in the soil and little watering, blackening of tomatoes also occurs.

Blackening on tomatoes

Important! If dark spots have formed on green tomatoes, this indicates the presence of serious problems that can be eliminated with the right approach.

Disease-resistant varieties

When planning to grow tomatoes in your summer cottage, choose varieties that are resistant to bacterial diseases. Similar varieties include:

• A little prince;
• Raspberry;
• Orange Giant;
• Virtuoso;
• Sunbeam;
• Black Prince;
• Carrot;
• Opera -1.2;
• Lights of Moscow;
• Lemon.

Try to purchase only certified seeds for sowing, strictly in trusted places with an established reputation. Follow all the advice of experienced vegetable growers, be sure to follow crop rotation and watering schedules, and strictly ensure that weeds do not grow in the tomato beds. Remember to destroy all weeds at the end of the season. If you follow all the rules, you will definitely get juicy, aromatic fruits that are not infected with bacterial diseases.

Why do tomatoes turn black in a greenhouse?

The crop can turn black not only in open ground, but also in a greenhouse. Therefore, it is necessary to understand why tomatoes turn black in a greenhouse and how to deal with it. Although the fruits are protected from adverse external influences, it is still necessary to maintain comfortable conditions in the greenhouse. If the care rules are not followed, you can lose a significant amount of the harvest, so it is necessary to start treating tomatoes in a timely manner.

Reasons for blackening of greenhouse tomatoes

Among the main reasons for the appearance of rot in a greenhouse, it is worth highlighting:

• soil contamination;
• high air humidity;
• incorrect temperature conditions;
• insufficient amount of fertilizers.

If it was noticed that green tomatoes began to darken, then it could be either frequent watering or too acidic soil.

Brown spot

A fungal disease that affects nightshade crops. The first signs are detected after flowering has ended. Light spots appear on the upper side of the leaf blade, and brown and gray plaque appears on the lower side. The leaves gradually curl and dry out. The bush does not receive enough nutrients and dies.

Brown spot. The illustration for the article is used from the site selhozobzor.ru

Preventive measures are taken to prevent the appearance of black spotting:

1. Preference is given to varieties with high resistance to the disease.
2. The seed material is calcined before sowing.
3. Regularly trim the lower branches to improve ventilation of the bush.
4. Do not allow the soil to dry out.

Folk methods of struggle

If tomatoes turn black on the bottom, folk methods will tell you what to do in this case. Here are the most common recipes that prevent the formation of spots on fruits.

Traditional methods of combating crop darkening

• Recipe No. 1. Squeeze 300 grams of garlic into 10 liters of water and leave to steep for 24 hours. After the time has passed, spray the tomatoes with the prepared solution.
• Recipe No. 2. You need to dilute 100 grams of kefir in 1 liter of water and spray it on the plants. Lactic acid products will prevent the fungus from multiplying and infecting tomatoes.
• Recipe No. 3. You need to make a solution: dissolve 1 glass of salt in 5 liters of water. Spray the tomatoes periodically with the prepared mixture until they are completely ripe.

Worth knowing! Using folk recipes, you can protect the crop from fungal proliferation and prevent the formation of other problems.

What are the dangers of diseases and what consequences can there be?

Regardless of what exactly causes the appearance of dark spots on tomato leaves, this state of affairs cannot be ignored. Even if the disease does not affect the fruit, it will still negatively affect the size of the harvest.

Important! The loss of leaves leads to a slowdown in photosynthesis, and this process is an integral component in the formation of fruits.

In addition, many tomato diseases are accompanied by the release of toxins that enter the fruit and make them unfit for consumption. Very often, pathogens enter tomato seeds, as a result they lose their germination capacity or form nonviable or disease-affected seedlings.

Finally, the causative agents of the disease - bacteria, viruses and fungi - multiplying uncontrollably and can soon spread throughout the entire area and even invade neighboring ones.

Chemicals

Folk remedies may not help in all cases. Every owner of a greenhouse or plot needs to know if black spots appear on tomatoes, what to do and what medicines to buy. It should be noted that the method of treatment is determined depending on what exactly the plant is infected with.

• Late blight. It is worth choosing medications such as Trichopolum, Hom, Fitosporin.
• Gray rot. Before you start spraying the plant, you must remove the infected fruits. If the rot is weak, you can use such remedies as Champion or Topaz, but if the problem is large-scale, then it is worth purchasing Ordan, Fundazol or Skor.
• Apex rot. A good remedy for treating the problem is Bordeaux mixture, which is prepared according to the following recipe: mix 100 g of quicklime in 1 liter of water, and dissolve 100 grams of copper sulfate in another container in 9 liters of water. Mix these two solutions and spray the bushes with tomatoes.
• Stem necrosis. Nothing will help the plant. The bushes must be torn out and burned, and the soil treated with Fitolavin.
• Alternaria blight. The plant must be treated with Ridomil, Antrakol, Ditan, Flint and other means. Treatment is carried out no more often than once every two weeks.

Types of blossom end rot and its symptoms

Tomato blossom end rot has two forms :

1. Physiological. Mostly on green fruits, a small depressed spot appears, which becomes brown and dry as it grows.
2. Bacterial. It appears in the form of not a dry, but a wet spot, first light green and then brown in color. The fruit gradually turns into a brown rotting mass with a specific odor. Moreover, such rot most often affects not green, but already ripening tomatoes, primarily the fruits lying on the ground. The latter may be healthy outwardly, since they often begin to rot from the inside, and only on a cut can black dead tissue be detected.

How can you treat tomatoes after harvest?

After the tomatoes have been harvested, they must be properly prepared for long-term storage. To do this, you need to treat the tomatoes with hot water: put them in water for a few minutes, at a temperature no higher than 60 degrees.

After time has passed, remove the fruits and let them dry naturally. This way, the rot will not spread further, and the fruits will be able to be preserved for some time.

Processing tomatoes after harvest

Prevention and treatment

There are practically no drugs developed specifically to combat black bacterial spot of tomato fruits. However, experienced gardeners always find a way to treat even the most complex diseases, and this disease is no exception. We will describe all possible treatment and prevention options for the disease.

Agrotechnical techniques

When removing weeds during the season, they are taken away from the garden, and in the fall all plant residues are burned. Tomatoes are planted in one area every 3 years. When working with seedlings, you need to be careful to avoid damage to young tissues; it is through them that the bacterium enters the plant organs.

In dense plantings, mature bushes form continuous thickets and are poorly ventilated. After rains, morning dew or improper watering, they remain wet for a long time. The minimum distance between bushes is 40 cm. The lower leaves are cut off as the stems grow, and excess stepsons are also removed; all pruning is carried out in dry weather.

Attention! Tomatoes should only be watered at the roots; the soil should not be over-moistened; as it evaporates, moisture accumulates on the leaves and stems, increasing the risk of tomato infection.

Tall varieties are tied up, and it is also advisable to lift low-growing varieties from the ground. When growing tomatoes in a greenhouse, the room is ventilated as often as possible. In open ground, tomatoes are planted in open, well-lit areas.

Chemical and biological drugs

Spraying with copper-containing preparations designed to combat late blight helps stop the development of the blight pathogen. It is better to carry out treatments in the early stages of the tomato growing season (before the ovaries appear) or immediately after the first signs of the disease appear. Already diseased plants are treated with Fitolavin or Ordan (3 treatments with a difference of 4 days).

Biological products such as Fitodoctor, Fitosporin-M and Trichodermin give good results; they are used for treatment and prevention. To control the disease, in conditions of high humidity and cool weather, alternate Captan and Mancozeb (according to the instructions). You can spray the bushes once every 1 or 2 weeks. Self-collected seeds, or purchased from an unknown manufacturer, are soaked for 30 minutes in hot water (50–52 degrees).

Symptoms

Small or larger watery spots of a dark, almost black color are visible on the leaves, petioles, shoots and fruits.

Reference! The size of the spots depends on the stage of the disease.

The infected plant has a depressed appearance.

A distinctive feature of the spots: irregularly shaped spots with a narrow chlorotic halo; young leaves are susceptible to necrosis. The spots do not unite into large foci, as with late blight, but resemble a black rash. On green fruits, the spots look like raised black dots, in contrast to bacterial canker, in which the spots are flat.

Mature fruits are rarely infected with black bacterial spot, which is associated with the acidity of the juice, which is unfavorable for the development of bacteria.