It happens that foliage, stems and fruits of cucumbers growing in a greenhouse or in an open garden bed are covered with marble stains that destroy plant cells. The disease that caused such a defeat of cucumbers is anthracnose or copperfish. In the article we describe the causes of the disease, symptoms and methods of its treatment.
Description of the disease
Anthracnose of cucumbers is a culture defeat by a fungal bacterium. In a progressive stage, the entire plant is covered with numerous light pink bulges filled with fungal spores resembling concentric circles.
Did you know? Not all fungi are harmful and dangerous: there is a high-quality and very expensive French wine "Chateau d’Iquem", for the manufacture of which grapes are specially infected with the "noble" fungus botritis cinera. Because of it, the content of berries becomes concentrated, which makes the taste of wine more refined.
Copperwort develops at positive temperatures (from + 4 ° С to + 30 ° С) and humidity of about 85–90%. The incubation period lasts 4–7 days, but if the conditions most favorable for the fungus have developed (at t +20 ... + 25 ° С), this period is reduced to 3 days. At temperatures below + 4 ° C and air humidity up to 60%, the disease does not appear externally.
The main reasons for the appearance and spread
Primary anthracnose can enter a plot or a greenhouse from a landfill, where the remnants of melons could contain fungal spores. In winter, after the growing season, the fungus in the form of sclerotia (parts of the mycelium of the fungus at rest) remains on the uncleaned parts, glasses, films of greenhouses or their rigid structures. If the disinfection of soil and glass has not been carried out, then in the next season this will serve as a guarantee of infection in the new greenhouse plantings of cucumbers.
Did you know? In the forests of the Amazon, biologists discovered a fungus that can process plastic into organics. Although there are fears that this mushroom may threaten modern civilization with the destruction of civilian infrastructure, there is hope that scientists will be able to direct these unique abilities of the fungus to eliminate household waste around the world.
Throughout the growing season, the fungus can be spread using conidia (fixed spores) in the following ways:
- when watering plants by sprinkling;
- with condensation moisture;
- when airing the greenhouses with a draft;
- when infected vines are in contact with healthy ones;
- through the working clothes of the gardener;
- through spider mites and aphids;
- carriers of fungal infection may be collected seeds from infected cucumbers.
Due to these reasons or their complex, plants can repeatedly overdose, which can significantly aggravate the disease.
The first signs and symptoms of the disease
Signs and symptoms of infection of cucumbers with anthracnose are:
- damage to the foliage in the form of brown spots with a dark brown border that spreads over the entire surface of the leaves or merges into a continuous film;
- the lesion gradually spreads to the other above-ground organs of culture, including the fruit, penetrating to a depth of 5 mm and leaving brownish spots pressed and elongated on their surface (as a result, cucumbers become unsuitable for food and sale);
- spots, merging and deepening, become an obstacle to sap flow in plants;
- in the heat, cracks appear on parts of the plant affected by anthracnose, and with increased humidity, the stems of the bush begin to rot.
Important! So that cucumbers and other garden crops are not threatened with the spread of anthracnose, hybrids resistant to fungal infection should be planted on the site.
The disease can also occur at the stage of growing seedlings:
- the roots of young plants are affected by depressed brown spots;
- when the leaves are damaged, they become covered with yellow or brown spots along the edge of the plates;
- with severe infection, the spotting merges into a single whole;
- the size of these "blots" vary and form a kind of gap;
- diseased leaflets become lifeless;
- stems are also affected by similar spotting, and then break;
- if the lesion spreads along the main shoots of plants, all seedlings die.
Methods of treating anthracnose cucumbers
If the cucumbers are damaged by copperfish, it is necessary to immediately begin their treatment. In the fight against fungus, fungicidal and folk remedies will help.
Fungicides
Fungicidal solutions containing sulfur help fight cucumbers anthracnose. They are able to kill spores of the fungus, which stops the spread of the disease.
Effective in the fight against anthracnose fungicides:
- Tiovit Jet;
- "Topaz";
- "Quadrice";
- "Poliram";
- "Fitosporin";
- "Copper oxychloride";
- Previkur;
- Abiga Peak;
- Home
- Cumulus
- Tsineb;
- Tsiram.
Important! When processing cucumbers with fungicides or folk remedies, it is necessary to protect yourself with a mask and rubber gloves, as well as wear protective clothing. After working with the preparations, hands and face should be thoroughly washed in soapy water, clothes should be washed, and the protective equipment and sprayer should be thoroughly rinsed in running water and dried.
These drugs are used immediately upon detection of the first symptoms of infection. With a total defeat of the culture, these funds will be ineffective.
In addition to the above drugs, in the fight against fungal infection, the following compounds are used:
- colloidal sulfur suspension (1%);
- Bordeaux mixture (0.5–1%);
- a solution of copper sulfate (0.7%), and after processing the plants are dusted with powder of coal, lime or chalk.
All products should be used strictly adhering to the dosages indicated by the manufacturers in the instructions.
Folk remedies
Gardeners also use folk remedies against anthracnose of cucumbers:
- Infusion of wood ash. Pour 3 tbsp into a 1 liter jar. l wood ash, insist 2 days and spray parts of plants affected by anthracnose.
- Onion husk infusion. Boil 10 l of water and 50 g of husk, let it brew for a day. Warm infusion (+ 25 ° C) to process bushes at the rate of 1 liter per 1 plant.
Disease prevention
To prevent the appearance of a fungal infection in the garden, you should adhere to preventive measures:
- before the onset of the garden season, treat the wooden parts of inventory and greenhouses with an aqueous solution of bleach (10 l - 20 g of lime per 10 l);
- lay the seeds in a well-fertilized, disinfected and heated soil;
- digging up the earth every year;
- at the end of the growing season, burn all remaining plant material and weeds;
- adhere to crop rotation rules, returning cucumbers to their previous beds no earlier than a three-year break;
- apply effective measures to combat insect parasites;
- when cultivating cucumbers in a greenhouse, reduce air humidity, avoiding moisture accumulation on the film;
- to spray plants after watering or rains with preventive means in order to prevent the resumption of infection with fungal spores.
Important! To prevent getting into the anthracnose site, it is necessary to purchase only healthy seed material and treat the seeds with disinfecting preparations - “Tiram”, “Immunocytophyte”, “Protectant TMTD” before planting.
The following can serve as prophylactic spraying solutions:
- Lactic iodine. Add iodine (30 drops) and grated laundry soap (2 tbsp.) To milk (1 l). Shake the resulting mixture and sprinkle cucumbers with it. The procedure to carry out the entire vegetation 1 time in 10-20 days. This will give the plants strength and resistance to disease.
- Ashy. Pour 1 cup ash to 2 liters of boiling water. The mixture is insisted for 14 days, after which add 3 tbsp. laundry soap and shake thoroughly. Spraying cucumbers to produce the entire season 1 time in 10-15 days.
When growing cucumbers, it is important to consider that there is always a risk of their defeat by fungal diseases. Therefore, it is important to acquire healthy planting material, conduct timely preventive measures to prevent infection at the site, carefully monitor the condition of the plantings and respond in time to the first signs of infection by treating plants with special anti-anthracnose agents.
