You have beautiful tomato plants grown in the greenhouse, and one day you noticed that the green fruits that were tied up turned black. What happened? Why do the leaves and fruits of the tomato grow dark in the greenhouse? You will find answers to these questions in this article.
Black tomatoes in the greenhouse - reasons
The most likely cause of blackening of tomato fruits is a disease of late blight , or brown rot. First, the upper part of the tomato leaves is affected, which are covered with brown spots. Then the disease passes to the lower parts of the leaves, where a grayish coating appears.
When the greenhouse is poorly ventilated and high humidity is maintained in it, the phytophthora quickly spreads to the green and ripe tomato fruits: they begin to rot and are no longer suitable for food. And when there is a big difference in daytime and night temperatures, dew drops out and fogs appear (this happens in August), then black tomatoes in the greenhouse most often because of these weather factors. Contributes to the appearance of the disease watering the tomato is not under the root, but on the leaves.
To avoid late blight, it is necessary to treat seeds with potassium permanganate before planting, and also to choose tomato varieties that are resistant to this disease.
Another disease that affects tomatoes in this way is vertex or gray rot. It can arise as a result of a shortage of certain trace elements, most often calcium. Tomatoes in the greenhouse, affected by the vertex rot, turn black from below. An uneven and irregular watering of plants can contribute to the appearance of such blackness.
Good results in the fight against vertex rot can be achieved by alternating the planting of different crops. If tomatoes are planted in the same place every four years, it will help to avoid the appearance of blackness on the fruits.
It causes a blackening of the tomato and excessive acidity of the soil. This can happen if you overfeed the plants with fertilizers containing nitrogen.