Tomatoes turn black during ripening - what to do?
Gardeners are well aware of the disease that affects still green ripening tomatoes. Black spots on fruits are considered one of the most common problems associated with tomatoes. What can you do about this mysterious vegetable disease?
Blackening of tomatoes is not a sign of a specific disease, but a reaction of the fruit to many types of diseases and unfavorable growing conditions. Blackening of fruits at the ripening stage can cause common rot, dry soil, excess or lack of fertilizers, tomato pests and other reasons. The best way to combat darkening is to prevent it, but already sick fruits can be saved.
First, you need to quickly determine what caused the blackening of the fruit. If the blackness spreads throughout the tomato, and the pulp under it is hard and devoid of juice, then the plant has been struck by dry apical rot. It appears when the soil is excessively salinized, which happens when a large amount of fertilizer is applied. The way out is simple: you need to stop feeding for a while. In addition, rot can appear with a lack of calcium. In this case, you can spray the tomatoes with a solution of calcium nitrate.
Tomatoes can also turn black due to very dry soil and the so-called "crawling" of the roots to the surface. In this case, tomatoes will intensively absorb moisture from the air, which usually occurs unevenly. Because of this, some fruits can turn black and spoil again.
Lack of fertilizer and disease
The reason for the darkening of the green fruits of the tomato may be a lack of fertilizer. Usually blackening occurs when tomatoes lack magnesium or boron. Top dressing in this case must be done in two stages - first add a little magnesium sulfate, and after a couple of days add boric acid. If blackening continues to appear on new fruits, then their reason is probably the development of a culture disease.
Diseases from which tomatoes darken are the worst option for a crop, since in this case it will be very difficult to return tomatoes to normal state. The disease could spread to tomatoes from a neighboring crop, be carried by the wind along with harmful spores, or, which happens much more often, simply expect a crop in the soil. If the darkening began to affect not only the fruits, but also the stems and leaves, then there is certainly a manifestation of a specific disease.
Most often, tomatoes are affected by late blight, it develops in conditions of high humidity, therefore it is not recommended to water the crop too often. Water only at the root. However, due to unfavorable weather conditions, such as morning dew and fog, moisture can accumulate on the leaves by itself. In this case, you just have to try to spray the plant with Bordeaux liquid.
When planting tomatoes, remember that it is better to plant the crop in a moderately ventilated place. In such conditions, moisture will not accumulate on the leaves too often and in large quantities. Do not hose the plant, and it is best to choose the morning for your watering routine. The evening moisture left on the culture will be a breeding ground for pathogenic bacteria all night, while the morning water, which has not had time to be absorbed, will quickly evaporate.
If you find blackened fruits on a tomato, they must be removed immediately and burned. The same applies to plants, the stems and leaves of which are covered with corresponding darkening.
Phytophthora, if it has become the cause of blackening, quickly spreads between the bushes that grow close to each other, and subsequently infects the entire garden, often spreading to other garden crops. Never eat darkened fruits, even if the disease has affected a small part of the fruit.
V. Kostenko