Blossom end rot is caused by a lack of calcium and mainly affects older tomato varieties. With proper care, you can prevent the disease.
Tomatoes are one of the most popular plants in the vegetable garden. The joy of a rich harvest is clouded when brown spots suddenly appear on the fruit. Tomatoes can be affected by blossom end rot at any stage of ripeness. The following article reveals what the disease is all about, how the hobby gardener deals with it and which preventive measures are advisable.
What is blossom end rot?
It is a metabolic disease. In addition to tomatoes, zucchini or cucumbers can also be affected. Blossom end rot occurs when a lack of calcium causes the tomato berries to rot from below. The dark spots only form on the underside of the fruit. This is because the fruit ripens on the base of the flower.
The tissue changes and appears sunken and waxy. As the process progresses, the pulp dries out and hardens. The previously brownish spots turn black.
Tip: Only individual fruits are affected by blossom end rot. The entire plant is not endangered.
If there is a lack of calcium, the cell walls lose their structure and collapse. The brown spots are ultimately parts of the tissue that have already died. Similar symptoms are also caused by excessive humidity.
Are there particularly susceptible tomato varieties?
The tomato originally comes from the Andes region and grows in hot and dry locations. Therefore, particularly old tomato varieties have problems with the climate in our latitudes. Oxheart or plum tomatoes are particularly susceptible to blossom end rot as well as brown and late blight.
Tip: Large and fleshy tomatoes are most commonly affected.
Well adapted to the local climatic conditions are various new breeds such as:
- Phantasia
- Vilma
- Philona
- Romello
- Picolino
Detecting blossom end rot
TypicalIdentification marks are the brown dots on the fruit base. In order to recognize these in good time, the tomatoes should be turned upwards from time to time or looked at from below. The patches darken, the tissue dries out, and eventually the entire fear discolors.
The risk of blossom end rot is particularly high in midsummer. If the disease remains undetected, the fruit will fall from the bush.
Control of blossom end rot
Because the disease only affects individual fruits and does not affect the stems and roots of the plants, blossom end rot is easily treatable and the harvest is not endangered.
If you keep an eye on your tomatoes, you will recognize the abnormalities described in the fruit in good time. All affected tomatoes are removed from the bush. In most cases, too little water has been used because the tomato plants absorb the calcium they need from the irrigation water.
The determination of the pH value provides information about the condition of the soil. You can determine this yourself using appropriate sets that are available in any hardware store. If the substrate is too acidic, the proportion of potassium and magnesium increases. These two substances have the property of binding calcium.
If the soil is too acidic, lime can be used. Lime can be applied in the form of rock flour and lead to an increase in pH. The fertilizer is applied to the leaves. Once their needs are met, the calcium absorbed through the roots is directed into the tomato fruits.
Coming soon:
- remove infected fruit
- Increase amount of water
- supply acidic soil with lime
What happens to the infected fruit?
If the disease is detected in time, only small parts of the fruit are affected. The taste of the tomatoes is not affected. After the brown areas have been generously cut out with a knife, the tomato can be eaten and processed as usual.
Tomatoes are often attacked at an early stage of development. In this case, further cultivation is not worthwhile. The fruits are removed and discarded. This can happen on the compost as the disease is not caused by fungi or bacteria.
It is now primarily a question of watering and fertilizing the plant sufficiently and thus stimulating rapid crop rotation.
Prevent blossom end rot
Preventive measures begin with the selection of plants. New breeds adapted to the local climateare less likely to suffer from blossom end rot. Plus, it can be exciting to grow the aromatic new strains.
Tomatoes are sensitive to moisture. The leaves should be protected from rain as much as possible. Greenhouses, shelters or special foil tunnels can be used as cover.
Keep the plants evenly moist. However, waterlogging should be avoided. The substrate should be enriched with a special tomato fertilizer. This gives the plants all the nutrients they need in the required concentration.
To ensure that the fruit is supplied with sufficient nutrients and that the power does not primarily go to the leaves, excess foliage can be removed from the tomato plants.