by Black spots on tomatoes are a sign of blossom-end rot. Inexperienced gardeners think it is a fungal disease and try to get rid of it with fungicides. But it is not that simple.
Blossom end rot occurs at any stage of plant development. Black spots slowly grow, and the affected tissues dry out and acquire a specific color: from light brown to dark brown.
Types of blossom-end rot and its symptoms
Blossom end rot of tomato has two forms:
- Physiological. A small sunken spot appears mainly on green fruits, which becomes brown and dry as it grows.
- Bacterial. It appears as a wet spot, not a dry one, first light green and then brown. The fruit gradually turns into a brown rotting mass with a specific smell. Moreover, such rot most often affects not green, but already ripening tomatoes, primarily fruits lying on the ground. The latter may be outwardly healthy, since they often begin to rot from the inside, and only on the cut can black dead tissue be found.
Causes of blossom end rot
Blossom-end rot most often appears due to high soil acidity, large amounts of salt, as well as a lack of moisture and calcium, which plants absorb from the soil. In turn, the supply of calcium to plants is often slowed down due to an excess of potassium, sodium, magnesium, and ammonium compounds in the soil.
Control measures for blossom-end rot of tomatoes
Let us note right away that fungicides are ineffective against blossom-end rot. Therefore, it is important to prevent the disease using preventive measures.
1. Before sowing, treat the seeds with a 0,5% solution of potassium permanganate.
2. A week before planting in open ground or a greenhouse, feed the seedlings with calcium nitrate at a rate of 1/2 tbsp per bucket (10 l) of water.
3. 5-7 days before planting tomatoes, add wood ash (200 g per 1 sq. m. of soil), chalk, lime or dolomite flour (400 g per 1 sq. m. of soil) to the soil. The amount of substances added may vary depending on the acidity of the substrate.
4. Water tomatoes only with warm water. Remember, watering should not be very frequent, but abundant.
5. During the growing season, carry out 2-3 foliar feedings with calcium nitrate (calcium nitrate) at a rate of 15-20 g per 1 liter of water.
Brexil Ca has also proven itself to be a good product, containing 15% calcium and 0,5% boron. It does not contain nitrogen, but calcium is in the form of a natural complex that quickly enters plant tissue. The solution is prepared at a rate of 10 g per 10 l of water.
6. When you find the first fruits with blossom-end rot, spray the tomatoes with a calcium nitrate solution (7-10 g per 10 l of water). Repeat the treatment after 5-7 days. Water the plants at the roots with the same solution on well-moistened soil (1-2 l per bush).
Treat your tomatoes carefully, don’t be lazy to look into the greenhouse or garden bed once more. With careful care, your green pets will not get apical rot and will give a rich harvest of beautiful and tasty fruits.
