One of the common problems associated with tomatoes is fruit rot. It can destroy the entire crop, not only of this year, but also of the future: destructive spores fall into the ground and infect it. Let’s try to figure out why tomatoes rot on the bushes, how to treat this disease.
What to do if tomatoes rot on a bush
As a rule, rot is caused by diseases such as late blight, early blight, wet or top rot, and various bacterioses. Almost all of them affect only the fruits, but with some, the leaves and stems become ill.
The fungus enters plants from contaminated soil, and is also carried by the wind from diseased bushes. Tomatoes with a weakened immune system get sick faster, this is facilitated by a deficiency of calcium and potassium, as well as violations in agricultural technology.
Rotting tomatoes in the open field
So, why do tomatoes rot in the open field? The main scourge of tomatoes is late blight . The disease manifests itself in the form of dark spots on the leaves and fruits. Initially, a dark brown spot appears at the bottom of the tomato, which becomes larger and larger over time. Then it turns black, this already signals that the tomato is rotting from the inside. The development of this fungal disease contributes to high humidity, rainy, cold summers. Hot weather can stop the development of the disease, but urgent action is needed at its first sign. Timely chemical treatment of bushes will prevent the spread of the disease.
Since in most cases late blight spores are in the ground, treating the soil with fungicides before planting will protect your tomatoes from this disease.
Rotting tomatoes in a greenhouse
Most often, tomatoes in greenhouse conditions are affected by blossom end rot, this is another reason why tomatoes rot on the bushes. Brown spots appear on green tomatoes, increasing as the fruit grows. The flesh under the skin becomes soft and rots. In most cases, the fruits fall from the branches before ripening. This is not an infectious disease, the cause of its occurrence is irregular watering and hot weather. If you come to the dacha once a week and water the bushes abundantly with water, the probability of hitting the bushes with this disease is quite high. Another reason is acidic or saline soil, lack of calcium and an excess of nitrogen.
Another reason why green tomatoes rot is Alternaria. The causative agent of this disease is thermophilic, the comfortable temperature for its life activity is +25…30 degrees, so it is most typical for the southern regions. But in the hot summer, this disease also appears in our latitudes, and abundant dews and rains contribute a lot to this. Dark brown spots appear on green fruits, usually near the stalk. At high humidity, tomatoes look like velvet on the outside, this is a raid from spores. Spots also appear on the lower leaves. Spreading over the entire area of the leaf, cause its death.
The second name is the hollowness of tomatoes or necrosis of the core of the stem. Unripe green fruits are covered with a whitish net, 2 brown rings appear on mature ones near the stalk, and there is a cloudy liquid inside the tomatoes. Tomatoes fall off the bushes even with a slight touch. Leaves, starting from the top of the stem, fade without changing color. Moist brown spots are noticeable on a tomato stem at a level of 15-20 cm from the ground. Then the stem cracks, mucus oozes out of it.
Tomatoes growing both in greenhouse conditions and in open ground are susceptible to black spotting. The smallest dark green spots on the leaves signal the onset of the disease. Over time, they grow in diameter, then darken. On the fruits, the spots are initially shiny, with a convex surface, then outwardly resemble scab. Rainy, warm weather contributes to the rapid spread of the disease, bacteria are carried by air currents and raindrops to healthy bushes.
Rotting tomatoes, how to process a bush?
In order to prevent late blight, a couple of weeks after planting, they are treated with trichodermin. A good result is the treatment of the bushes with Bordeaux liquid, the first time, 2 weeks after planting in the ground, the second, a week and a half later. If you are not a supporter of chemicals, you can use garlic infusion, which is prepared from 10 liters of water, 1.5 cups of garlic and 1.5 grams of potassium permanganate.
To make plants less affected by fungal diseases, tomato bushes are watered with a solution that includes iodine (40 drops), calcium chloride (30 g) and water (10 liters). For each plant, 0.5 liters of solution is used. In parallel, fertilizing with phosphorus-potassium fertilizers is carried out. To increase immunity during the period of budding and the beginning of flowering, spraying with immunomodulators (Epin-extra) is carried out.
But what to do if the tomatoes rot, and you find the initial symptoms of phytophthora damage? In this case, the bushes are sprayed with Bordeaux liquid (1%), Oxyhom (2 tablets per 10 liters of water), copper oxychloride (40 grams per 10 liters of water). All preparations, except Bordeaux liquid, can be used no later than 3 weeks before harvest. Spray in the morning, after the dew has dried. The greenhouse is ventilated after the procedure. To avoid the addiction of pathogenic microflora to drugs, they are changed every year.
For the treatment of alternariosis, the same means are used as for late blight. To prevent the disease, it is recommended to cultivate disease-resistant varieties: Novichok, Zemlyak, Lana, Gruntovy Gribovsky 1180, Novinka Pridnestrovie and others.
When vertex rot is detected, the bushes are sprayed 3-4 times with a 0.4% solution of calcium nitrate, or calcium chloride. The interval between sprayings is at least 5-7 days. For 10 sq. m. area requires 0.5 liters of solution. Recommended varieties: Alpatyeva 905a, Zvezdochka, Lakomka, Gusar, Moravian miracle, Volgograd 5/95, Rychansky.
In case of bacteriosis, spraying with Kartocide is carried out, in a proportion of 50 gr. for 10 liters of water; Oxyhom at the rate of 2 tablets per 10 liters of water. Processing is carried out no later than 20 days before picking tomatoes in the open field; 4 days in greenhouses. To avoid infection through the soil of new plantings, after harvesting, all tops and other plant debris are removed.