How to deal with currant rust and prevent its appearance
Currant is one of the most unpretentious and hardy garden plants. Black, red and white varieties of this culture can grow in all regions of our country. She is not demanding to care and is capable of producing crops even with minimal attention of the gardener. However, without protection from diseases and pests, the shrub often dies.
The most common and dangerous disease of currants is rust. It often infects crops and causes leaves, shoots and berries to fall off. Without timely treatment, the bush dies. How to deal with rust on currants and prevent its appearance, we will tell further.
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Types of rust on currants and their symptoms
The causative agent of rust is a fungal infection. There are many varieties of fungi that can cause orange spots on leaves... The currant is affected by goblet and columnar rust.
These types of rust have differences in symptoms. However, the treatment will be the same regardless of the type of pathogen.
Goblet rust is caused by the fungus Puccinia ribesicaricis. Infection occurs in early spring. The fungus settles on the underside of the leaf blade and then spreads throughout the plant. At the beginning of development, it is difficult to detect the disease. The leaves begin to rust in early June and fall off in mid-summer.
Signs of illness:
- Orange dots appear on the underside of the plate. They are usually located along the veins. Over time, the points become bulky and increase in size. By the middle of summer, they are transformed into goblet red growths, from which a rusty powder pours out. The growths darken, increase in size and grow.
- The outer side of the leaf is covered with yellow depressed spots. Gradually they merge, and the whole leaf turns yellow.
- The leaves become stiffer, turn brown, bend and deform. They seem shaggy to the touch.
- Young shoots stop developing, curl and dry out.
- The disease spreads to the formed ovaries. Infected berries become white and inedible.
Columnar rust is caused by a fungus of the genus Cronartium ribicola Dietr. The infection attacks the underside of the leaf blade and spreads throughout the plant.
Symptoms of the disease:
- Light yellow irregular spots appear on the outside of the leaf. Drawing of them resembles a mosaic. Later, the spots take on an orange tint.
- Where there were spots on the outside of the leaf plate, bulging growths in the form of spots and stripes form over time on the inside of the leaf. They have a yellowish tint, over time they begin to rust and darken. By the end of the growing season, curved papillary (columnar) formations of reddish-brown color grow on the spots, which consist of many tiny spores and hang from the leaves. The leaves begin to curl and dry out.
- Often disease spreads to branches, ovaries and shoots. The affected areas are also first covered with spots, and then with hanging columnar formations.
The first signs of the disease become noticeable in the middle of the growing season of the plant. Rusty spores grow in late summer or early fall.
It is interesting! The homeland of goblet rust is Siberia.It was from there that it spread throughout Europe.
Causes of rust
The reasons for the development of rust and getting it on the site are rooted in maintenance errors and factors independent of humans. Why does it arise:
- The proximity of conifers. It is coniferous plants (including juniper) that carry columnar rust.
- Weeds. The intermediate host of goblet rust is sedge and other marsh plants.
- Last year's foliage and plant remains - the fungus hibernates in them.
- Pests. They not only eat the plant, reducing its immunity, but also spread fungal infections. Such pests include spider mites, currant gall midge and aphids.
- Planting currants in wetlands and places with a close location of groundwater. Increased soil moisture is an ideal condition for the development of a fungal infection.
- Prolonged precipitation. High humidity combined with low air temperature weakens the immunity of plants and contributes to fungal infection.
The fungus is spread over the site by the wind. There is a great risk of infection if there are intermediate hosts or diseased plants in the garden.
Why is the disease dangerous?
Rust not only makes the currant bush aesthetically unattractive, and the leaves unsuitable for use in conservation, but also threatens the life of the plant. The harm that this disease causes:
- Loss of crops. Few ovaries are formed on a diseased plant. Many of them fall off. Fungus-affected fruits, which have already formed, become unsuitable for consumption.
- Disruption of photosynthesis stops plant development.
- Falling up to 50% of leaves. Young shoots often fall off.
- Reduced cold resistance - the currant bush may not survive the winter.
- Decreased immunity. Currants become susceptible to other diseases.
Without treatment, the flexible remains on the plant for several years. As a result, the currant dies.
It is not difficult to treat rust at the beginning of its development. If signs of disease are noticed in time, the disease will not cause serious damage to the plant, and it will survive the winter.
In the later stages, the disease is also treated, but this year it will not be possible to try the harvest. For the winter, the plant that has suffered rust is covered with spunbond and snow.
Agrotechnical measures to combat currant rust are the basis for the treatment of the disease. However, they are only effective when combined with antifungal agents.
For the treatment to be successful, the leaves and shoots of the currant are examined. Particular attention is paid to the underside of the sheet plate.
All affected areas of the plant are removed, removed from the site and burned. Places of cuts are lubricated with garden pitch.
Weeds, fallen leaves and other plant debris around the infected bush are removed. They dig up the soil.
Attention!The problem with using only agricultural techniques is that even if all affected parts are removed from the bush, fungal spores are likely to end up on healthy leaves and shoots. In this case, a relapse of the disease will occur. If you use only medicinal products, without removing the diseased parts of the currant, the struggle will be long. In this case, relapses also cannot be avoided.
Folk remedies for rust treatment are considered the safest. They do not harm the environment and humans, they are used even during the fruiting period and before harvesting. But they are less effective than chemical drugs, so they are used at the beginning of the development of the disease.
What to do in case of currant rust infection:
- Baking soda soap. In 10 liters of water, 0.5 pieces of grated laundry soap and 120 g of soda are diluted. Stir the product until all ingredients are dissolved. Spray the bushes and the soil around them.
- Onion and garlic infusion. 0.5 kg of garlic and 0.5 kg of onion are chopped in a meat grinder along with the husk. The resulting gruel is poured into 10 liters of water and left to infuse for 2 days.Then the infusion is filtered and used to spray the plants.
- Manure. 1 kg of manure is diluted with 2 liters of water. The mixture is infused in a warm place for a week. Then diluted with water in a ratio of 1:10 and used for spraying currant bushes.
- Fermented milk product with iodine. 1 liter of kefir, whey or sour milk and 40 drops of iodine are poured into a 10 liter bucket. The rest of the volume is filled with water at room temperature.
Biological products are prepared on the basis of microorganisms that do not harm plants, but destroy the fungus. They are not dangerous for humans, ecology and animals, so most gardeners prefer to use them.
Biological products for combating rust:
- "Glyocladin". It is made on the basis of a fungus that has a depressing effect on other microorganisms.
- "Trichoderma Veride". It is made on the basis of fungi that penetrate the mycelium of the pathogen and destroy it.
- "Baktofit". The composition contains bacteria that inhibit the action of fungal infections.
- "Sporobacterin". Effective against goblet and columnar rust.
- "Fitosporin-M"... The most popular biological product. The main active ingredient is a bacterium that is effective against most fungi that cause currant diseases.
The main advantage of biological products is that they not only help to cope with the infection, but also increase the immunity of the plant, and also stimulate growth. The disadvantage of such funds is that they do not work against all diseases.
Chemicals are most effective in treating rust. They quickly destroy the fungus, are not washed off by rain and protect the currants from re-infection within 2-3 weeks after application. They help to cope with the disease, even at a late stage.
The disadvantage of such drugs is toxicity. They are harmful to humans, ecology and animals. If the bush is processed during flowering or fruiting, the harvest from it cannot be eaten.
The chemicals are applied in the spring before flowering or after harvest. If other means do not help, you can process the currants at any time, but then this year you will have to be left without a crop.
Note! Fungicides are not washed away by rain. Therefore, re-processing after each precipitation is not required.
How to treat rusty leaves:
- "Previkur". The systemic fungicide is absorbed into plant cells, making it toxic to fungi. The solution is prepared just before processing. For this, 7.5 ml of the product is taken for 5 liters of water. "Previkur" is first diluted in a small amount of water, then poured into the rest of the liquid.
- "Speed". The contact fungicide acts directly on the fungal infection, but after 3 treatments it becomes addictive. To prepare a solution, dilute 1 ml of the drug in 10 liters of water. The treatment is carried out at a temperature not lower than + 15 ° С, since in colder weather the effectiveness of the product decreases.
- "Topaz". A systemic fungicide stops the development of the fungus and its spores. Does not wash off by rain, lasts for 14 days after application. It is considered a relatively safe fungicide. To prepare a mixture for spraying, 2 ml of the product are dissolved in 10 liters of water.
- Copper sulfate also belongs to fungicides. In addition, it has the properties fertilizers... They can spray currants not only before flowering, but also 2 weeks before harvesting. The product is not used during flowering.
- Bordeaux mixture withIt is made of copper sulphate and slaked lime. Suitable for prevention and treatment. For 10 liters of water, take 2 tsp. drug.
How to deal with rust properly
To cope with rust, it is important not only to find the right product, but also to use it correctly:
- All diseased parts of the plant are removed before processing.
- Spraying the bush is carried out in the morning or in the evening, when the sun is inactive, so that burns do not appear on the leaves.
- When preparing the drug, the proportions are observed. Otherwise, the plant will also burn.
- When treating a bush from rust, all its parts are abundantly sprayed. Pay special attention to the underside of the sheet.
- Not only the bush is cultivated, but also the soil around it.
- Sprayed with fungicides no later than 2 hours before precipitation. Chemical agents are applied to diseased currants at least 2-3 times. The intervals between the application of the preparations are 2-3 weeks.
- Biologicals are applied to the plant a day before precipitation. The processing is repeated 2-3 times. The interval between sprays is 7 to 14 days.
- Folk remedies are washed off by rain, therefore, after precipitation, repeated spraying is carried out. The interval between treatments is 5-7 days.
Treating rust and eliminating its consequences is much more difficult than preventing disease. Basic rules of prevention:
- Fallen leaves and plant debris are removed in autumn. They dig up the soil.
- The weeds around the currants are removed.
- The area where currants grow should not be swampy or be located where groundwater is located close to the surface. It is not recommended to plant shrubs near coniferous forests.
- In the spring, before flowering, currants are poured with boiling water. After that, spray with a solution of copper sulfate.
- After prolonged precipitation, preventive treatment is carried out. Use biologics or folk remedies.
Rust resistant currant varieties
In order not to face the problem of rust on currants, they choose varieties with resistance to this disease:
- Belarusian sweet;
- Black veil;
- Primorsky champion.
Currant rust is a dangerous disease that often causes the death of a plant. There are two types of the disease, but regardless of the pathogen, the treatment will be the same. To do this, use special drugs and folk remedies. The main thing is to start treatment on time and follow the basic rules.