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Most varieties of tomatoes fall into the category of vegetable crops showing a high level of resistance to infectious diseases. However, sometimes gardeners notice that gray rot has appeared on tomatoes. To take effective measures to prevent the disease and get rid of its consequences, it is necessary to have an idea of the nature and conditions of the spread of infection.
Gray rot quickly spreads to tomatoes growing in close proximity
What is this disease
Gray rot (late blight) is a dangerous fungal disease that affects fruit crops, including tomatoes. The causative agent of the infection is spread by air current, infecting planting vegetables with rot. Another way fungus spreads is through water. Gray rot spores that persist in the soil for several years fall on plants during irrigation.
Causes of appearance
It has been noticed that gray rot usually appears after pinching tomatoes. During the procedure, wounds are formed that, under normal conditions, do not pose a threat to plants. But if pathological microorganisms enter the structure of the tomato bush, then infection with gray rot occurs. Unfavorable weather factors accelerate the development of the disease.
The negative impact is:
- temperature drop;
- high humidity;
- violation of air circulation.
The problem is exacerbated by the presence of fallen leaves and fruits. The spread of gray rot is facilitated by swampy areas and high acidity of the soil.
Gray rot on tomatoes in a greenhouse is a fairly common occurrence. Greenhouse plants are infected more often than vegetables growing in garden beds. When growing tomatoes in greenhouses, there are two factors that contribute to the development of infection:
- Cramped growing conditions.
- Insufficient supply of fresh air and high humidity.
Best of all, spores develop at a temperature of +5 0C to + 40 0C. Optimum air humidity for pathological processes is above 80%. Failure to disinfect the greenhouse also contributes to the spread of gray rot.
Microorganisms from the genus saprophytes, which include gray rot, also infect onions, cucumbers, beets, potatoes
Symptoms of the disease
Regular monitoring of planting tomatoes allows you to identify the disease at an early stage. Signs of the disease are found near the damage that occurred after the removal of stepsons. Initially, a whitish spot forms on the stems and leaves of the tomato.
A few days later, a characteristic gray coating appears – fungal spores. Subsequently, the spots occupy an increasing area, the color of the formations changes from gray to brown. The fruits become soft.
What is dangerous disease
From gray rot, tomato stalks injured during pinching most of all suffer. Knots form inside the tissue, capillary necrosis develops. As a result, water stops flowing, which leads to wilting. At the final stage, the fungus destroys the plant completely. Yellow spots form on unripe fruits. Subsequently, the entire tomato is covered with bloom. Gray rot on tomatoes in a greenhouse looks very unpleasant.
The flesh under the spots softens and rots, which makes the fruits inedible.
How and how to treat gray rot on tomatoes
Experienced gardeners are sure that if you treat tomatoes from the moment the first signs of gray rot are discovered, then the negative consequences can be overcome. With a massive defeat of landings, it is extremely difficult to cope with the infection.
Agrotechnical methods
In fact, agrotechnical methods are more aimed at preventing the disease than at its treatment.
Among the effective methods of agricultural technology:
- Compliance with the irrigation regime. Tomatoes require plentiful, but not frequent watering.
- Loosening the soil after watering.
- The use of a sharp knife when pinching. The tool requires pre-treatment.
- Weeding weeds, which often become a breeding ground for gray rot.
- Cleaning of leaves, shoots and stepsons after the stepson procedure.
When watering plants, direct a stream of water under the root, preventing irrigation of leaves and fruits. It is especially important to follow this rule when caring for tomatoes in greenhouses or greenhouses, where the humidity level is always higher than in open garden areas.
Folk remedies
At an early stage of the development of the disease, you can do without chemicals. To combat the emerging gray rot, tools from the arsenal of folk experience are used. The advantage of compositions based on recipes developed by centuries of practice is safety for humans and beneficial inhabitants of the garden plot (birds, bees, etc.). In the elimination of gray rot on tomatoes are effective:
- Laundry soap solution. To prepare it, 100 g of soap chips are diluted in a bucket with hot water. Bushes affected by gray rot are poured with a cooled solution so that a soap film is formed on them, which inhibits the reproduction of fungal spores.
- Boric acid. To prepare a 1% solution, you need 1 g of boric acid per bucket of water. A simple folk remedy prevents the spread of infection, stimulates the formation of shoots and ovaries, strengthens the immune system.
- Baking soda. A solution of soda is used to spray tomato bushes. According to the recipe, 10 g of soda is required for 100 liters of water.
Instead of laundry soap, green soap can be used to eliminate gray rot. The solution will need 80 g of liquid soap (or shavings) per 10-liter bucket of water.
Chemical preparations for gray rot
When the infectious process is running, it is advisable to use chemicals. If gray rot is detected on tomatoes, the bushes can be treated with one of the following means:
- Profit;
- Ditan;
- Integral;
- Fundazol;
- Speed;
- Abiga Peak;
- Oxicom;
- Bordeaux mixture.
All synthetic preparations for the destruction of gray rot are recommended to be used in accordance with the attached instructions. Otherwise, instead of curing the plants, they can be ruined. Re-treatment is recommended no earlier than ten days later.
The chemicals used to control gray mold are toxic and are therefore prohibited during the harvest period.
Biopreparations
Biological products are highly effective in the elimination of gray rot. Successfully destroy the fungus compositions:
- Fundazol. The components included in its composition inhibit the development of spores and at the same time fight against the larvae of harmful insects. Fundazol is used both for the prevention of fungal infections and in the treatment of tomatoes from plant mycoses.
1 g of Fundazol is diluted in 1 liter of water and sprayed with a solution of plants infected with gray rot
- Maksim. Popular with gardeners and farmers, the fungicide kills spores, suppressing the infection in 3-4 days. A significant plus is the ability to spray greenhouse plants during the formation of buds.
When preparing the Maxim solution, 4 ml of the drug is diluted in 10 liters of water
- Agate 25K. The action of the biological agent is aimed at suppressing pathogenic microflora and strengthening the immunity of fruit crops. At the initial stage of the development of mycoinfection, the bushes are treated with Agat 25K solution at the rate of 50 ml per 1 liter of water.
Agat 25K can be used up to three times per season, as it does not accumulate in fruits
Glyocladin, Trichodermin, Zerox biological agents have proven themselves to be excellent. When planning processing, it should be taken into account that the substances contained in biological products lose their properties under the influence of sunlight. Agricultural technicians recommend spraying on cloudy days or in the evening.
How to get rid of gray rot on tomatoes in a greenhouse
As already noted, the fight against mycoinfection indoors has its own characteristics due to the high density of plants and high levels of humidity. Gray rot on tomatoes in the greenhouse develops intensively (see photo). In an isolated space, it is preferable to use folk remedies and biological preparations to cure tomatoes from gray rot, since chemical compounds accumulate in the structure of plants in the absence of a constant supply of air and high humidity.
Methods for controlling infection in greenhouses are identical to those used when growing crops in open ground
How to prevent gray mold on tomatoes
Like any disease, gray mold is easier to prevent than to cure. Measures to prevent the development of infection in plantings of tomatoes and other vegetable crops include:
- timely implementation of agrotechnical procedures (watering, loosening);
- pinching, taking into account sanitary measures, which includes the destruction of damaged and removed shoots;
- carrying out disinfection work in the greenhouse at the end of the winter period;
- regular ventilation of greenhouses and greenhouses at the end of irrigation.
It is equally important to purchase planting material in places that are trustworthy. Also, when growing seedlings at home, it is advisable to use soil that has been disinfected.
To disinfect the instrument during pinching, alcohol-containing substances and aniline dyes are used.
Sustainable varieties
Breeders are working to create varieties of tomatoes that are resistant to gray rot. There are varieties of tomatoes that show relative resistance to infection. In this regard, there are varieties of tomatoes that grow well in greenhouse conditions and in open ground:
- Vasilevna;
- Pilgrim.
Special requirements are imposed on varieties of tomatoes grown in greenhouses. For cultivation in greenhouses and greenhouses hybrids are recommended:
- Bohemia F1;
- Ural F1;
- Firebird F1;
- Charisma F1;
- Vologda F
These varieties are resistant to many types of infections, including gray rot. In addition, according to gardeners, hybrid forms of tomatoes are able to produce a good harvest with a lack of sunlight.
Conclusion
Gray rot on tomatoes can ruin the crop and create unfavorable conditions for gardening in the future. But existing methods of prevention and treatment can cope with the problem. The choice of how to fight the infection remains with the owner of the garden plot.
