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Raspberry rust appears as small round spots of bright yellow, orange or brown color. This is a dangerous fungal disease that can lead to premature leaf loss, thinning shoots and general weakening of the plant, which will have a negative impact on yield. Therefore, if signs of infection are detected, you should immediately treat it with drugs or folk remedies.
Description and types of rust with photos
Raspberry rust is a common infectious disease caused by a microscopic fungus from the order Rustaceae of the same name. Pathology occurs everywhere, especially in regions with a humid climate - the Black Sea region, the Far East. There are two types of rust - black and white. They differ in pathogens and external signs.
Black
Black rust of raspberries is caused by the fungus Phragmidium rubi idaei (Pers). Main stages of disease development:
- In spring, small bright yellow spots begin to appear on the top of the leaf. This is a sporogen that resembles small pads.
- Brown balls form on the bottom side.
- Then they begin to turn black, and after the autumn leaves fall, the pest overwinters directly on the foliage, sheltering from frost.
The appearance of this type of raspberry rust can be visually determined by numerous yellow dots on the foliage, as well as by premature leaf fall. It is worth considering that the appearance of a pest will have a bad effect not only on the yield, but also on the winter hardiness of the plant.
Signs of the disease can be identified by visual examination
Orange
Raspberry orange rust is caused by a related fungus called Gymnoconia peckiana. Some signs of the disease coincide with black rust, others are different:
- in early spring there are noticeably many weak shoots on the plant with deformed leaf plates;
- balls also form on the underside of raspberry leaves, but they are colored not brown, but bright orange;
- Gradually, the affected foliage dries out, begins to curl and falls off in June.
Foliage affected by orange rust quickly dries out and falls off.
Reasons for appearance
The main cause of raspberry disease is infection with fungal spores. Microorganisms parasitize the foliage and multiply quickly, as a result of which not only the crown, but also the shoots weaken. Even with proper care, the occurrence of the disease cannot be completely excluded. It is known that the provoking factors of its development are:
- excessive watering;
- thickened plantings (high air humidity);
- violation of the rules of care (for example, if you do not remove fallen raspberry leaves, this will certainly lead to the pest successfully overwintering and again parasitizing the bushes).
- rainy summer, climatic features of the region.
What to do if there is rust on raspberries
Crimson rust is treated in different ways. The most powerful means are chemical fungicides. They are used only in the early stages of raspberry development, i.e. in spring or early summer. They are also effective for prevention.
However, using chemicals at the fruiting stage is dangerous - toxic substances can accumulate in the berries. At this time, it is better to use biological drugs. You can also try treating raspberries against rust with folk remedies. They give good results in the early stages of the disease. Home remedies can also be used as a preventive measure.
Chemicals
The active ingredients of chemicals (fungicides) are artificially synthesized compounds. They are very effective in controlling raspberry rust, but can be toxic. Therefore, it is better to use such products before fruit set. Moreover, they should not be used during flowering.
Many fungicides are dangerous to bees, so they are not used during raspberry flowering.
Among the best remedies for raspberry rust are the following:
- Bordeaux mixture;
- "Abiga Peak";
- "Polyram DF";
- "Kuproksat";
- "Cumulus DF".
For example, the consumption rate of the working fluid of the Abiga-Peak preparation is 400 liters per hectare.
Folk remedies
Folk remedies are effective in the early stages of raspberry rust development. Their main advantages are their natural composition and the absence of toxic substances. You can use homemade solutions, infusions and decoctions at any time, including shortly before picking berries.The main recipes are listed below:
- Take 10 ml of an alcohol solution of iodine and dissolve it in 10 liters. Treat raspberries against rust three times every two days.
- Mow, chop the wormwood, fill the bucket halfway, fill it with water at room temperature and leave in the shade until foam appears. Then filter and dilute with water five times. Raspberries are treated several times to prevent rust.
- Fill 2/3 of the bucket with wood ash and add water, let it sit under the sun, and stir occasionally. As soon as the surface turns yellowish, carefully drain the upper part, dilute the rest with water twice and begin treating the raspberries from rust.
- Take five tablespoons (without top) of soda ash and dissolve in 10 liters of water. Add 100 g of laundry soap shavings and leave for several hours. Spray the leaves.
- If there is a lot of horsetail growing nearby, it is picked, chopped and filled to half a bucket. Fill with water at room temperature to the top, then boil for several minutes, cover with a lid and leave for a day. Strain and, without diluting, begin processing the bushes.
Agrotechnical techniques
Agrotechnical practices serve to prevent raspberry rust. Their essence comes down to ensuring proper planting and care of the bush. The basic rules are:
- do not make plantings too thick;
- Regularly prune shrubs and thin out the crown;
- remove fallen leaves in the fall;
- periodically inspect the bush and completely remove the affected foliage (if there is a lot of it, along with the shoot);
- do not plant shrubs in the place where there was an old raspberry tree recently (1-2 years ago).
Bad neighbors are strawberries (strawberries), potatoes, tomatoes, eggplants and other nightshades.
The place for planting raspberries must be chosen taking into account what crops grew there before
Biological products
Biological preparations are based on strains of microorganisms that effectively destroy the causative agent of black and orange rust. At the same time, the products are not toxic, so they are used even at the fruiting stage (maximum one week before harvest). The main means are:
- “Respect 25%”;
- "Strekar";
- "Fitolavin, VRK";
- "Abacus Ultra, SE";
- "Acanto Plus, KS."
Preventive measures
Preventing the spread of rust is much easier than dealing with the consequences of its appearance. Experienced summer residents have developed several preventive measures that are worth paying attention to:
- Choose the right landing site. It should not be located in a low area - otherwise, after rains there will be constant stagnation of moisture. Also, raspberry bushes are not planted close to buildings or bushes - in this case there is no flow of fresh air, which also provokes waterlogging and the development of rust.
- Avoid dense plantings. Even if there is not enough space on the site, it is better to sacrifice the “extra” seedlings than to place them close to each other. The minimum distance between holes should be 70-80 cm.
- In early spring, even before the buds swell, raspberries are treated with any chemical or biological fungicide. Along with it, you can use a urea solution with a concentration of 8%.This will not only prevent the development of rust, but will also serve as a source of valuable nitrogen compounds that ensure rapid growth of the shrub.
- Leaf litter in the fall should be immediately removed and burned, or simply taken away from the raspberry tree.
- It is recommended to trim raspberries periodically (in late autumn or early spring). This prevents thickening of the crown, which is also useful for preventing rust.
- Follow other rules of care, which also affect the resistance of raspberries to diseases and pests - weeding, loosening the soil, fertilizing, mulching in summer and winter.
One of the preventive measures is regular pruning of bushes.
Conclusion
Raspberry rust is a fairly common disease, especially in regions with a humid climate. It is possible to cure raspberries affected by infection in the early stages. If the disease is advanced, it is easier to prune the affected branches and burn them.
