Prevention and treatment of gray rot on tomatoes
A lot of trouble gardeners when growing tomatoes delivers gray rot on tomatoes. Photos of summer residents are a clear demonstration of how damaged plants look, and measures taken to prevent this disease not taken in time lead to economic losses in the garden.
Prevention and treatment of gray rot on tomatoes
Source of disease and contributing factors
The causative agent of gray rot on tomatoes is the fungus Botrytis cinerea Pers, which affects vegetables on the open ground and grown in closed greenhouses. Transmitted mainly by air, during the collection of vegetables and in the process of moving from one bush to another, gray rot on tomatoes leads to withering and death of the plant. Among the provoking factors that contribute to the emergence and development:
- excessive humidity
- excess of the content of nitrogen components in the soil.
Reviews of experienced gardeners, among other conditions that cause the appearance of gray rot on tomatoes, note:
- violation of the composition of the soil, when in the absence of proper sterilization the causative agent of the disease remains - fungal spores, which can provoke infection of the vegetable crop in droves in the greenhouse,
- planting unverified tomato seeds,
- violation of the moistening order in the greenhouse, leading to accumulation of excess moisture, and vice versa, insufficient watering of plants, leading to weakening of tomatoes and a decrease in their resistance to disease.
By spraying conidial plaque, fungal conidia are transferred with water during irrigation. Dense sclerotia formed at the end of the horticultural season on plant debris ensure that the pathogen remains in the soil for a long time.
Among the main sources most susceptible to the disease, from which infection of tomatoes occurs, are cucumbers, lettuce and others.
Symptoms of rot
Among the main signs indicating the presence of rot on tomatoes:
- foci of decay on the fruits of gray-brown color with a visible fluffy gray coating
- spots on areas near the fastening of leaves and tomato brushes,
- stems of tomatoes stricken around the perimeter.
The most common gray rot of tomatoes during fruit ripening. Simultaneously with the stems that are injured by a fungal disease, which are affected first, without taking measures against it, the infection spreads to the top of the shoots, inflorescences and the vegetables themselves. As a result, if you do not treat and fight the pathogen, the fungus spreads rapidly throughout the greenhouse. To get acquainted with the characteristic signs and type of damaged tomatoes allow photos of summer residents who have encountered this disease.
Discovered rot-affected vegetables are immediately collected and must be destroyed to prevent the spread of fungal disease.
Fungal disease grows in 3-5 days, covering the stems with spots. A little later, the spots become pale to straw hues, turning into blurry bands. The first week on the outbreak itself there is no sporulation of the rot fungus. Necrosis developing inside the stem leads to an obstruction of water supply through the affected area, resulting in the death of a vegetable crop. Leaves growing on top of the necrotic areas begin to turn yellow and fall off. Together with them, the stem is covered with aerial roots.
Agricultural technology against rot
The modern agricultural industry has developed enough measures for the prevention and treatment of gray rot on tomatoes and other vegetable crops. However, the frequent delay in the implementation of preventive measures and their application with a great delay reduce their effectiveness.
It is necessary to take preventive measures during
Among the main reasons why gardeners are late in taking protective measures is the lack of proper diagnosis of the initial signs of the disease at the initial stage. They are often confused with other plant diseases - didimella, fusarium and other pathogens.
Judging by the responses of summer residents, agrotechnical measures show the best efficiency in the fight against gray rot.
- The agrotechnical protection of tomatoes against gray rot involves, first of all, planting those varieties of tomatoes that are more resistant to this fungal disease. Although vegetable growing does not indicate resistant varieties with a resisting property against fungus gray rot, tomato varieties Piligrim and Vasilievna are noted among tolerant hybrids.
- The second agrotechnical technique in the fight against the gray rot of tomatoes is considered to be ensuring the necessary level of humidity in the greenhouse.
- The third way to help prevent the spread of fungal disease is the careful handling of tomato bushes in the process of removing vegetables and foliage. This involves removing damaged leaves and stems using a sharp knife and exclusively in dry weather. The remains of the removed plants that serve as the source of the spread of the fungal infection must be destroyed.
- The drip irrigation and covering the tomato bushes with mulching materials show great effectiveness in the fight against gray rot when growing tomatoes.
Among the agrotechnical measures to protect tomatoes from gray rot, is the treatment of plants at the vegetative stage of development. This is done with sodium humate. The percentage of reduction in the spread and development of gray rot on tomato stalks is up to 48-54.
Biology and chemistry against rot fungus
In addition to agrotechnical measures in the fight against fungus and in the treatment of tomatoes for gray rot, biological and chemical measures are widely used.
They involve the treatment of tomato stems, which must be treated with a suspension of trichodermin. Do this after the cliff of the affected foliage, which stops the appearance of secondary fungal foci. Together with trichodermin, it helps to fight and shows itself well as a biological defense against gray rot on glyocladin tomatoes, which moisten wet areas. Such laborious methods of combating gray rot show good results with long-term effectiveness. Using these biological suspensions, tomato bushes can be sprayed, doing this in the daytime, allowing the plant to dry before evening coolness.
Prevention and treatment of the disease can be done with the help of chemicals - fungicides. During the growing season, when signs of the disease are detected on tomatoes, the stems and leaves of the plants are coated with fungicidal preparations. In advanced cases, it is recommended to spray tomato bushes with fungicides in a continuous way, which prevents the intensive spread of fungus in the greenhouse and allows you to save the crop.
Reviews gardeners are advised to stick to the schedule for processing tomatoes with fungicides:
- in May make a mandatory coating and spray the affected areas with drugs,
- repeat the treatment after 2 weeks,
- in June - July, smear the damaged areas, in the second half of August, with the spread of the disease, treat the tomatoes with drugs in a continuous way,
- re-process in early September.
Prevention of tomato protection involves also treating the soil with preparations and steaming substrates, and disinsecting greenhouse structures.