Cladosporiosis, or brown spot, of tomato leaves is a fungal disease that is difficult to get rid of. It affects the leaves, then the stem and fruits. The tomatoes develop dark or olive-colored spots that are hard to the touch. I no longer want to eat such vegetables. The entire crop can be destroyed due to cladosporiosis.
Tomato varieties resistant to cladosporiosis
You can fight the fungus for a long time and persistently, but I prefer to choose varieties that are resistant to the disease. I'll tell you about the most popular ones.
Cladosporiosis
Russian tomato is delicious
The variety also belongs to the mid-early variety, but unlike Solnyshka, the bush grows 60-80 cm in height and is considered low-growing. Ripening lasts on average 110 days. The variety produces large fruits, the weight of which can reach 300 grams. Canning such tomatoes will not work.
Russian tomato is delicious
How to treat tomatoes against cladosporiosis
Cladosporiosis should be combated from the moment the first symptoms of the disease appear. You can treat the aboveground part of tomato bushes with chemical or biological preparations, or use folk remedies. Which of these remedies are most effective and at what stages of the disease each of these remedies can be used will be written below.
Chemicals
Chemicals for treating tomato bushes should be used with extreme caution, since they have the ability to “absorb” into the fruit, and consuming such products is harmful to the human body. Therefore, after chemical treatment, at least 20 days must pass, and only then can ripe tomatoes be collected for consumption or canning. Therefore, after chemical treatment, at least 20 days must pass, and only then can ripe tomatoes be collected for consumption or canning
Therefore, after chemical treatment, at least 20 days must pass, and only then can ripe tomatoes be collected for consumption or canning.
Such drugs are used when the disease has already spread widely among this vegetable crop, and other means in such a situation are no longer effective.
It is recommended to use the following fungicidal drugs to combat cladosporiosis:
- Ditan NeoTek 75;
- Bravo;
- Abiga Peak;
- Polisher;
- HOM;
- Copper oxychloride.
All of the above chemicals should be diluted in strict accordance with the instructions, and personal protective equipment should be used when processing plants.
If necessary, fungicide treatment is repeated 12-14 days after the previous one.
Biological agents
There are drugs that are more harmless to humans and plants that effectively fight this fungal disease - these are biological agents. Although they are quite harmless to people, when diluting them you should also adhere to the dosage indicated in the instructions:
- Fitosporin is diluted as follows: no more than 10 g of the drug is diluted in 20 liters of water. Greenhouses are treated with this solution several times with an interval of 12-14 days;
- Fitolavin 300 must be diluted as follows: take 40 ml of the drug per 20 liters of water. The vegetative mass of tomatoes is sprayed with this solution;
- Pseuvobacterin-2 is diluted strictly according to the attached instructions. Moreover, this drug helps fight not only cladosporiosis, but also some other diseases.
Traditional methods
Traditional methods of fighting fungi are effective only at the initial stage of the disease. As soon as the first brown spots are discovered on the foliage, you need to treat the bushes with the following solutions:
- iodine chloride. This solution is suitable for processing not only the vegetative mass of tomatoes, but also for treating the soil, which must be filled with such a solution to a depth of at least 9-11 cm. A similar solution is prepared as follows: dilute 1 tbsp in 10 liters of water. a spoonful of potassium chloride and add 40 drops of iodine tincture;
- Another effective remedy for combating cladosporiosis is whey diluted in water. The dilution rate is 0.5 liters of whey per 5 liters of water;
- garlic tincture. This infusion is one of the most effective against brown spot. Place a crushed clove of garlic (or 500 garlic cloves) in a bucket of water, add 30 drops of iodine and leave for several hours;
- milk solution. A liter of milk and 30 drops of iodine are diluted in a bucket of water;
- weak solution of potassium permanganate;
- ash decoction In order to prepare it, you need to dilute 300 g of ash with a liter of water and boil over low heat for half an hour. Dilute the resulting decoction with water to 10 liters and you can treat diseased plants.
All these means should be used in turn. If, after treating tomato bushes with folk remedies, cladosporiosis continues to spread, then biological agents or chemicals should be used to combat it.
Tomato Beefsteak
The name of the variety speaks for itself. The fruits are large, fleshy, and bright red in color. This variety is preferably planted in a greenhouse; it may not ripen in open ground.
Tomato Beefsteak. Photo used from etsy.com
Tomato Coral beads F1
The fruits are formed in small clusters. The total weight of one such bunch can reach 500 grams, while the weight of one tomato is only 17-19 grams. Coral beads are so-called cherry tomatoes. They can be preserved and used to decorate dishes. The hybrid variety feels good both in open ground and in greenhouse conditions.
Coral beads. Photo used from sadovod.net
Causes of brown spotting
The main factor in the activation of cladosporiosis fungus spores is unfavorable weather conditions. Dampness and proximity of infected plants leads to rapid infection and spread of infection. In addition, in poorly ventilated greenhouses the air becomes excessively humid, which also causes the fungus to multiply quickly.
Brown spotting on tomatoes appears with frequent watering or stagnation of moisture. Under such conditions, the spore maturation period is only 2 weeks. And the pathogen can get onto plants even from dirty garden tools.
A greenhouse climate is an ideal habitat for fungus. Once in a greenhouse, the fungus quickly localizes on weakened plants, waiting for the most suitable conditions for reproduction. They usually occur in mid-June, when it gets quite hot outside and the air in the greenhouse gets very hot. With improper watering, poor ventilation and thick planting of tomatoes, the moisture takes a long time to evaporate and condensation forms. Water accumulates in the thicket of plantings; the leaves and stems themselves are constantly wet. All this has the best effect on the rapidly increasing activity of conidia. When air humidity reaches 90% and temperatures above 25 degrees, the fungus begins to rapidly reproduce.
Attention!
The causative agent of the disease is transferred to plants by watering or a light blow of wind.
Why does this disease occur on tomatoes?
Infection of plantings occurs at the moment when conidia (special spores) of the fungus fall on a healthy plant.
The mycelium produces them through asexual reproduction. The appearance of conidia is similar to dust. They are easily transported by air currents and settle on plants in the greenhouse. In addition, the source of infection can be an infected instrument or irrigation water. The insidiousness of the disease lies in the fact that the spores can persist for a long time without a host plant, for example, in the soil. An air humidity level of 90-95% promotes the development of brown spot.
Under such conditions, the spores come to life and begin to germinate. Once in the greenhouse, the disease very quickly spreads to all tomato bushes. Temperature fluctuations also contribute to the development of fungus.
On a note! If air humidity drops to 70%, the development of cladosporiosis stops.
Tomato Boheme F1
Mid-season low-growing hybrid with very average performance. It does not have a high yield, but it is stable and can be planted in open ground. The fruits weigh up to 140 grams, maybe much less. By planting such tomatoes, you will not break a record, but you will definitely have a harvest.
Tomato Boheme F1. Photo used from satu.kz website
I tried to plant all these tomatoes in my garden. Some of them gave an excellent harvest, some died at the seedling stage. However, all of the presented varieties are resistant to brown spot and other diseases.
Methods of treating the disease
The fight against brown spot should begin as early as possible, then the chances of defeating it will be higher, and in the initial stage of the defeat it will be possible to get by with traditional methods. If the scale of infection is already serious, then treatment of cladosporiosis on tomatoes will need to be carried out with potent agrochemicals.
Chemicals
To guarantee a bountiful harvest, you need to know tomato diseases and their treatment, because the success of the treatments depends on how quickly the pathogen is identified and identified.
Chemicals are highly toxic, so after spraying the plantings, fruits are not allowed to be consumed until 3 weeks after the procedure. It is not safe.
Treat tomatoes in greenhouses and in open areas with the following broad-spectrum fungicides:
- Bravo. A drug of low toxicity is used to protect tomatoes from fungal diseases that attack stems, leaves and fruits. The number of treatments per season should not exceed three procedures. For 1 hectare of tomato plantation you will need 3 liters of product. Treatment begins when there are prerequisites for the development of the disease - high humidity levels, temperature changes, thickening. The procedure is repeated after 10 days. Consumption per 1 ha is 400-600 liters of working solution. When using the drug Bravo, you need to know that it does not have medicinal properties; it is used for the prevention of cladosporiosis.
- Copper oxychloride. The agrochemical shows its effectiveness within 5 days. The number of treatments against fungal disease is 4 procedures. For 1 sq. m consume 100-150 ml of working fluid. To prepare the solution, use 40 g of the product per 10 liters of water.
- A mixture of colloidal sulfur (3 tbsp), copper sulfate (1 tbsp) and polycarbacin (1 tbsp) is diluted in 10 liters of water with the addition of 2 tbsp. l. rare soap. The working solution is used to treat plants affected by the fungus.
- Bordeaux mixture. If the product is diluted incorrectly, there is a high probability of burns on tomato leaves, so the working solution should be prepared in strict accordance with the instructions. The total number of procedures per season should be 4 treatments. For spraying, use a weakly concentrated 1% solution. The interval between treatments is 10 days.
It is important to take safety precautions when working with chemicals. Carry out spraying in protective clothing using a respirator, goggles and gloves
Biological drugs
Products based on beneficial fungi and bacteria are very popular among gardeners. This is an excellent alternative to chemicals. They are completely harmless. Treats cladosporiosis or brown spot on tomatoes using the highly effective drug Trichodermin. The first time it is used when preparing the soil for planting seeds, then it is added to water for irrigation at intervals of one month. Foliar treatments of tomato bushes are done with a working solution prepared at the rate of 100 ml of product per 10 liters of water.
Folk remedies
To treat tomatoes in a greenhouse covered with brown spots, use:
- Garlic infusion. To spray tomato bushes, prepare an infusion of crushed raw materials (0.5 kg) and 10 liters of water. The poured garlic is kept for 24 hours, after which it is passed through a filter material and used for processing, having previously diluted 1 liter of infusion in 10 liters of water.
- Light pink solution of potassium permanganate and ash mixture. Watering with the addition of these products is carried out alternately. The ash solution is prepared from 300 g of the product and 1-2 liters of water, after which it is diluted in 9 liters of liquid. Perform treatments effectively at the initial stage of development of a fungal disease.
