To get a good harvest of garden crops, vegetable growers often have to solve several problems. Basically, they relate to the selection of the desired assortment, increasing the fertility of the land, organizing care and watering, and combating pests and diseases. Prevention of viral and bacterial lesions of tomatoes requires special attention.
In recent years, vegetable growers have been paying attention to the fact that brown spotting of tomatoes, like some other diseases, interferes with getting a good harvest of this crop. In some years, in vegetable gardens, the disease affects up to 80% of tomato plantings. This happens in greenhouses without heating and in the open field. To successfully organize the prevention of a disease, you need to understand who or what causes it.
- Biology of the causative agent of tomato brown spot
- How to deal with brown spot on tomatoes
- Prevention of cladosporium disease
Biology of the causative agent of tomato brown spot
Cladosporium fulvum Cooce is the causative agent of cladosporium disease or brown spot. Infection occurs when conidia of this fungus enter the plant. Conidia differ from ordinary spores in that they are not formed in special organs of the cladosporium fungus - sporangia, but directly on the outgrowths of the mycelium of conidiophores. Conidia formation refers to asexual reproduction. Conidia are light, dust-like, and easily fall on a wide variety of objects.
Cladosporium conidia can get on healthy plants from the air, from water, from working tools. The danger of this method of infection is that conidia can survive without a host plant. They winter well on plant debris, in the soil and on it, on greenhouse structures. Conidia are resistant to high and low temperatures and drying.
Getting on the leaves, in conditions of high humidity, the conidia of the cladosporium fungus begin to germinate. The main factor for rapid growth is humidity above 90 - 95%. Most often, fungal infection of the leaves becomes noticeable in the middle of the growing season, when the tomatoes are gaining color and forming an ovary.
On the upper side of the leaf plates, yellowish spots of various shapes and sizes become noticeable. If you turn over the leaf plate, then a light bloom is clearly visible from below, which gradually darkens and turns brown. In addition, the texture of the plaque becomes denser and velvety. These are germinating conidia, causative agents of tomato brown spot. If effective measures are not taken at this stage, the leaves will begin to lose their color and shape, they turn yellow, dry out and crumble.
Weakened leaves die off first. Losing green leaves, tomatoes, along with them, lose the ability to photosynthesize in the amount necessary for fruiting, which significantly reduces the yield. The pathogen can settle on flowers and infect a young ovary of tomatoes. If you do not recognize the disease in time and do not start a fight with it, then you can lose most of the harvest.
How to deal with brown spot on tomatoes
Treatment of plants from brown spot should be started immediately. With a slight defeat, folk methods of struggle will help.
Folk ways of fighting:
- spraying with garlic infusion. A pound of garlic cloves, you can add a garlic arrow, chop in any way. Pour 10 liters of water and leave for a day. Then generously spray all the tomato bushes in the area or in the greenhouse.
- alternate watering a tomato with a solution of potassium permanganate with watering with a solution of wood ash. Dilute potassium permanganate until pink, and to obtain a solution of ash, you need 300 g of ash, pour them with 1 - 2 liters of water and heat to a boil. After 15 minutes, remove from heat and bring volume to 10 liters.
If folk remedies did not help, then you will have to resort to chemicals.
Chemical agents against brown blight of tomatoes
When resorting to spraying with chemicals, you need to remember that if three weeks have not passed after it, tomatoes cannot be eaten.
- spraying with contact agents from the Bravo series. Prepare the solution according to the attached instructions, process the tomato planting. This should be done in dry weather. After 7 - 10 days, repeat the treatment.
- spraying with Fitolavin can be recommended for large areas of disease. A solution of this drug easily penetrates into the cells and heals tomatoes from the inside. In greenhouses, tomatoes are processed twice, in open ground up to 3-4 times.
As you know, the best treatment is timely prevention.
Prevention of cladosporium disease
Before planting a tomato, the soil can be shed with a phytosporin solution. The same drug is added to water for irrigation, alternating watering with clean water with watering with phytosporin solution. To avoid the spread of the disease, preventive spraying of the tomato is used after planting the seedlings. They do this with a break of 14 days. For this, the same Fitolavin is suitable.
For prevention, you can shed tomato bushes with a yeast solution. It is enough to dilute 0.1 kg of yeast in 10 liters of water. To prevent infection, you must follow the principle of crop rotation and do not plant tomatoes after potatoes, peppers, eggplant.
In addition, after harvesting, all tops and other plant residues are removed from the garden and destroyed. Compliance with the humidity regime will also be a good preventive measure against tomato brown spot. At a humidity of 60 - 70%, conidia do not germinate. In addition, growing disease-resistant tomato hybrids and varieties will significantly reduce the risk of infection:
- Our Masha F 1
- Victoria F 1
- Red Comet F 1
- Red cherry
- Titanic F 1
The above preventive measures will help to avoid loss of tomato yield from brown spot disease.
Video about tomato brown spot and treatment methods: