Tomatoes can be grown both outdoors and in greenhouse conditions. To obtain a high-quality harvest, this vegetable crop requires special care and prevention of various diseases in any growing conditions.
- Some infectious diseases
- Noncommunicable Diseases: Watering Errors
- Top rot
If you look at the diseases of tomatoes in the photo, you will notice that many diseases affect not only the leaves and stems, but also the fruits. Diseases of tomatoes can be conditionally divided into infectious and non-infectious. Infectious diseases include fungal, bacterial and viral lesions, brief information about which you can see here and below. We will also talk about tomato lesions that are non-infectious.
Some infectious diseases
Mosaic is one of the most common viral diseases of tomatoes. Moreover, this disease can affect not only greenhouse plants, but also those plants that grow in open soil. The mosaic affects the leaves, changing their color and shape. First, yellowish-green spots appear on the leaves, while they begin to wrinkle and curl. As a result, tomatoes practically do not bear fruit, turn yellow and die.
Plants affected by the mosaic are recommended to be pulled up and burned. To prevent the appearance of this disease, the seeds should be treated with a weak solution of potassium permanganate, and subsequently also water the seedlings with it once every three weeks. Passionate also refers to the preventive measures of this disease.
Some tomato diseases in the photo give a clear idea of the course of the disease. For example, the brown spot of tomatoes is characteristic of film greenhouses and manifests itself in the formation of brown spots with a velvety gray bloom on the underside of the leaf. Accordingly, the plant dies. The disease is spread by spores of the fungus, therefore it is easily transferred to other healthy plants.
Brown spot develops actively at high humidity. Therefore, as a preventive measure, it is necessary to stop abundant watering and ventilate the greenhouse well. And after removing ripe fruits, spray the plants with foundation.
Signs of suboptimal watering are often confused with infectious diseases.
With a lack of moisture, tomatoes slow down growth, abundantly throw off ovaries and flowers. The leaves fall down, turn yellow at the tips and wrinkle. To bring the plants to their senses, it is not recommended to flood them with large amounts of water at once. It is better to give them some settled water and pour it after a couple of days as expected.
Excess water also affects the development of the tomato. Most often, stagnant water causes decay of the roots, leaves on tomatoes fade (old and young at the same time) and they begin to fall off. The root collar may develop watery or brown spots. If it is immediately impossible to carry out drainage work in such areas, then it is better to transplant the bushes, slightly cleaning the roots from rot.
Improper watering can lead to cracking of tomato fruits. This usually happens when, in the heat, summer residents suddenly appear on the site and, seeing a dull picture in the garden, rush for a hose. Plants are shocked by the sharp supply of water and quickly supply it to the ovaries. The integumentary tissues burst and infections can enter. It happens that the tissues overgrow in time, create a new coating. It has been noticed that tomatoes are prone to cracking when overfeeding with mineral water.
Burnt areas on tomato fruits are whitish spots of various sizes. It happens that solar radiation burns a very large part of the fetus. The wounds that appear under the influence of rays dry up over time and do not allow the fruit to develop. Then they wilt, and the taste of such fruits is greatly deteriorated.
This non-infectious form of the disease is very typical for greenhouse tomato cultivation. It manifests itself at low humidity (about 40%) and high temperatures, as well as with an excess of nitrogen. Such extreme conditions for the development of tomatoes cause the outflow of nutrients from the fruit, metabolism is disrupted, tissues are destroyed.
Initially, green oily-watery spots appear on unripe fruits (as a rule, on the first set clusters). Then they acquire a brown hue and, as it were, are pressed into the fruit and become denser, having a concentric shape at its top. Affected fruits begin to ripen faster, become a place of penetration of secondary infections, and can rot and fall off.
If you have not previously encountered such a disease, then it can be easily identified from the photo, unlike many other diseases, where you have to analyze the symptoms in a complex. To prevent the appearance of apical rot, the following measures are necessary:
- Greenhouse ventilation;
- Regular watering;
- Introduction of calcium into the soil before planting;
- Strict control of applied nitrogen doses.
If the greenhouse is installed in the country and during the week there is no way to control the level of moisture in the soil, then it is better to install an automatic water supply. There are all kinds of sensors and programmable relays (timers) that will help ensure at least daily watering. Such devices work both from the mains and from alkaline batteries.
For automatic ventilation of greenhouses, special transoms are installed, which, depending on the ambient temperature, rise by themselves, providing an influx of fresh air. They are autonomous and volatile.
So, when you determine the causes of deviations in the development of a tomato from a photo, keep in mind that diseases can be infectious and non-infectious. In the latter case, it is important to observe the dosage of mineral water, observe the modes of lighting, watering and airing.