Cladosporiosis is the second most harmful and widespread fungal disease of tomatoes after blight. Among summer residents, more commonly known as brown or olive spot. One after another, the harmful fungus infects the leaves without affecting the fruit, and inexperienced gardeners may not pay attention to the spots and wonder why tomatoes are so poorly fruited. Drying leaves they take for lack of moisture and increase the rate of watering, thereby aggravating the situation. But you just need to take a closer look at the affected leaves in order to identify such a disease as a cladoosporia of tomatoes.
The first signs of infection and causes
The first signs of cladosporia appear first on the lower leaves. Vague yellowish spots are formed on their upper side, which eventually turn brown, and on the lower side of the leaves a thin, light-gray deposit is visible. It consists of a spore, through which the fungus spreads. Gradually, the leaves dry, curl and die off, moving from lower to upper. Occasionally green fruits and flowers are affected.
Fungal spores are exceptionally viable. They withstand both drought and prolonged freezing. They overwinter on the remains of tops, on the shelves of the greenhouse, in the soil. Upon the occurrence of favorable conditions, the fungus begins to actively proliferate. The best microclimate for it is unheated greenhouses, in which the humidity is high and the temperature is maintained within 20–25 ° C.
Methods for the treatment of tomato cladosporia
At the initial stage, the development of cladosporia successfully inhibits folk remedies and biological preparations. If the first signs are missed, the fungus with might and main is hosted in the greenhouse, the most reliable way to fight against a cladosporia of tomatoes is to use chemicals. Before processing the beds should be prepared. For this you need:
- reduce humidity
- tear off all the lower leaves, take out of the greenhouse, burn,
- remove weeds on which fungus spores can remain.
You also need to inspect each bush, remove all badly affected leaves, extra stepchildren. This measure will improve air exchange, reduce the number of pathogenic spores.
Therapeutic compositions of available tools are able to cope only at the beginning of a lesion with cladosporia. Most often they are used for prevention. Traditional recipes are not costly, do not harm tomatoes and human health, in some cases are an additional feeding for plants. The following are popular among them:
- Potassium permanganate. Prepare a solution of pink color, making sure that all the crystals have dissolved, and sprayed the bushes.
- A glass of sifted wood ash is poured with a liter of water, boiled for about half an hour. The liquid is cooled, filtered, used for spraying and watering of the tree circle.
- A tablespoon of potassium chloride (it is sold as a mineral fertilizer), 40 drops of iodine tincture are diluted in a bucket of water and sprayed with tomato bushes. The mixture is convenient because it can be stored for several days, and it is possible to process tomatoes every day.
- Half a liter of milk or a liter of whey is mixed with 25 drops of iodine tincture, made up to 10 liters of water, sprayed with tomatoes.
For spraying there is a certain rule - it is possible to process plants only in the early morning, in the evening or in cloudy weather in order not to burn the leaves.
The action of most biologics is based on the ability of some bacteria to inhibit the development of pathogenic fungi kladosporioza. Such bacteria primarily include strains of hay sticks. In the process of vital activity, it releases substances that have a destructive effect on the causative agent of cladosporia. The very hay stick for people and plants is safe, except for rare cases of allergy to it. Drugs that contain hay bacillus culture as an active ingredient include:
- Fitosporin - the ready working solution is mixed with water in the proportion of 5 ml per 10 l. Tomatoes and the greenhouse itself are treated 2–3 times. After two weeks, the treatment is repeated.
- Fitolavin-300 - 1 tablespoon bred in a bucket of water. Spray the tomatoes according to the instructions.
- Pseudobacterin is a new broad-spectrum drug. It is diluted and used according to the instructions.
Such drugs as Gamar, Alirin, Gliokladin are similar to the listed ones. All of them normalize the microflora in the soil and on the surface of the leaves. When using them, it should be remembered that the hay bacillus is afraid of the action of direct sunlight, so the treatment should be carried out in cloudy weather or before sunset. To process tomatoes, you should choose a time so that the treating substance does not wash away the rain.
If you could not cope with cladosporioz by sparing means, you will have to use chemicals. They certainly do not bring health benefits, but applying them strictly according to the instructions will help reduce harm to a minimum and preserve the harvest. The following fungicides help in the treatment of tomato clavosporia:
Such well-known preparations as copper oxychloride, colloidal sulfur, Bordeaux liquid are also known for their fungicidal properties.
In order to minimize the likelihood of tomato disease with Kladosporosis, agronomists recommend planting plants with a high resistance to disease. There are practically no varietal tomatoes immune from brown spot, but breeders succeeded in inculcating this quality into hybrids. These include the following varieties: “Space Old F1”, “Titanic F1”, “Swallow F1”, “Business Lady F1”, “Malika F1”, “Victoria F1”.
Timely treatment measures will save tomatoes from cladosporia. Do not bring the plants to the disease, make preventive measures, plant resistant varieties of tomatoes, and then do not have to resort to the means of treating the disease.
Description and harm
The very name “brown spot” (the concept of “klaosporioz” is more common among specialists) shows the “appearance” of the disease - the spots of the corresponding color (already in the mature stage of the disease) cover tomato leaves.
But not only foliage is sick and dies. Launched cases of cladosporia tomato, left without timely treatment, lead to the death of the entire plant, and the owners in this case remain without the expected yield.
For tomatoes that are grown in greenhouses or under a greenhouse film, the threat of this disease is more than real, and you need to be prepared to treat the tomatoes growing in this way.
A disease goes through several stages in its development, which should exacerbate the vigilance of gardeners - to start a fight at the first signs means to conquer the illness, to allow the transition to the last stages - it means to lose in the fight against it.
Did you know?Spores of cladosporus were found at more than a kilometer of oceanic depth, in amber and on wood in sediments of the tertiary period - this is one of the most ancient fungal organisms.
Causes and pathogen
Not all varieties of tomatoes are resistant to cladosporia - this will be discussed below in more detail.
The first of the objective reasons for the infection of this disease is the natural susceptibility of a number of tomato varieties.
The second could be called environmental conditions - pathogens prefer heat (over +25 ° C) and humidity (over 80%).
The third reason is the increased penetrability of infection to objects of infection - this is due to the peculiarities of its pathogens.
And they differ from the usual fungal spores. These are the so-called "conidia", with which Cladosporium fulvum Cooke reproduces asexually. Conidia “dust particles” are carried by the lightest movements of air. They settle on any items. By treating the beds with ordinary garden implements or by pouring them from the usual hose, you may not even suspect that at the same time you are transferring the pathogens of a tomato infection to plants that you love.
For the specificity of these carriers of the disease are characteristic:
- ability to live without the plant itself (can live in the soil),
- resistance to drought and freezing temperatures,
- long (up to 10 months) viability.
Important!The decrease in air humidity below 70% stops the disease process.
The first signs in tomatoes
As soon as the brown spot touches your tomatoes, you need to immediately apply the known measures to combat it.
The possible first signs of cladosporia should be monitored during the growing season and the beginning of flowering. Do not be lazy at this time to look at the inner parts of the leaves - there, in the event of infection, appear, as at the very beginning of decay, gray spots. A signal for inspecting the reverse side of the foliage can (and should) be fine light green (or, alternatively, yellowish) spotting on its outer side.
In order not to return to the further description of the dynamics of the development of the disease, let us point out immediately and especially the subsequent steps:
- Kladosporiosis reaches its peak value, spreading from the bottom up, hitting not only the youngest leaves, but also parts of the stems.
Outwardly, this is expressed in the gradual darkening of the spots, and within the plant organism the supply of nutrients to all its areas and, consequently, the development of entangled fruit - seems to be intact and intact, grows very weakly and becomes mature.
Learn how to deal with brown spot on strawberries.
From the moment the first painful symptoms appear, kladosporiosis or brown spotting of a tomato becomes an extremely unpleasant reality for you, which forces you to search for and apply the necessary treatment methods. They, by the way, a lot.
Biological products are good for their harmlessness to people, animals and beneficial insects. It is recommended to use trichodermin against cladosporia specifically (it is effective against other fungal diseases).
Bring it, for the first time, directly into the soil before planting seedlings. After that apply every month, simultaneously with watering.
In addition, spraying is performed with a solution (according to the instructions) of a liquid substance of the leaves of tomato bushes.
Considering that the dissolved trichodermin dries very quickly, the procedure should be carried out in cloudy weather to avoid additional heating of the greenhouse by the sun's rays. Read more about preventive biologics.
Defeating kladosporioz using agrotechnical methods can only be the most radical way - to destroy all infected plants. Therefore, agrotechnical techniques in this case should be considered either as an element of the integrated control of the disease, or as a purely prophylactic agent.
These could include:
- Destruction (burning) of infected leaves and the rest of the plant mass after harvesting.
- Strict adherence to the rules of crop rotation.
- Periodic airing of the greenhouse.
- Sparseness planted bushes.
- Optimization of watering in order to avoid waterlogging.
To grow varieties of tomatoes that are resistant to cladosporia can also be considered a certain kind of prevention.
There are at least two such varieties. Of the most well-known tomatoes, many put the variety “Our Masha F1” in the first place, because he, besides resistance to this disease, also has excellent fruits.
Among the first are also called varieties:
- "Vezha", who came to us from Belarus (loses a little to the first place with the size of fruits).
- "Delicacy" with pink tomatoes.
- "Space Star F1" - It is desirable to additionally spray it with additional prophylactic (“Alirin-B” and / or “Gamair” preparations).
- "Funtik" - its like "Evpator", start up, in the core, in processing, without using fresh.
Did you know?Soviet scientist N.I. Vavilov pointed to South America as the genetic center of origin for the primitive form of tomatoes.
The specks that appeared on the leaflets of tomato seedlings should become a guide to action, especially the disease is curable. With a little effort, a good harvest awaits you.