Spots on leaves for diseases of red currant - how to treat?

Diseases of red currants often cause a drop in yields, which means they cannot be ignored. First of all, the symptoms of any disease appear on the leaves and young shoots. Regular inspection of the bush will allow you to timely identify the problem and get rid of it, without waiting for the advanced stage of the disease. Control measures should be aimed at preventing and eliminating the causes of diseases. For red currants, proper agricultural technology is also important.

Causes of the appearance of red spots

There are many diseases in red currant. Among them are powdery mildew, and septoria, and terry. However, the reason for the appearance of exactly red spots on the leaves is:

• anthracnose;
• rust;
• attack of red-gall aphids.

Before proceeding with the treatment of a diseased bush, it is necessary to carry out an accurate diagnosis in order to understand which particular cause of leaf damage had to be faced. To do this, you need to carefully consider the symptoms.

Anthracnose

Anthracnose belongs to the diseases of the fungal group. On red currants, this disease manifests itself not only on the leaves, but also on leaf petioles, stalks, and berries. Initially, symptoms appear on young leaves in the form of small reddish-brown bumpy spots with a dark edging.

When overgrown, the affected areas merge, which leads to premature drying out and foliage falling off. In the active stage of the disease, white dots appear at the lesion sites, consisting of ripe fungal spores, easily carried by the wind. The disease spreads rapidly from one plant to another. Contributes to its development:

• lack of phosphorus-potassium fertilizers;
• excessive density of shoots;
• lack of lighting;
• warm humid weather;
• plant residues not removed in time.

As soon as the disease has been detected on the bush, it is necessary to cut off all affected leaves, and at an advanced stage, the diseased branches entirely. Then you should treat the bush with antifungal drugs. Secondary spraying is carried out in the fall after leaf fall.

Rust

Red currants are often affected by columnar and glassy rust. Both diseases, like anthracnose, are caused by a fungus. Columnar rust of currant gets sick towards the end of summer. If you lift a branch of a diseased bush, on the underside of the leaves you can notice red convex growths consisting of spores. The upper side of the leaf plates is covered with yellow spots.

The goblet form affects currants in the spring at the flowering stage and manifests itself in several symptoms at once. The upper part of the leaves is covered with small yellow dots. On the reverse side, swellings in the form of orange bubbles are noticeable, which gradually take the form of glasses filled with rust spores.

Both types of fungus also affect black and white currants, but red varieties are much more likely to get sick. As in the case with other fungal diseases, they contribute to the development of rust:

• humid, warm and windy weather;
• weakened plant immunity;
• poor sanitary condition of the site.

Natural reservoirs of the goblet rust pathogen are conifers and various types of sedges. Therefore, if there are cedar or pine forests nearby, sedge thickets, the risk of the disease increases many times over.

Red-gall aphid

The presence of a pest can be diagnosed if brown, red, yellowish swellings appear on the upper side of the leaf plates.Most often, it is the red currant varieties that suffer from the attacks of the gall aphid. The pests themselves can be found swarming on the underside of the leaves.

Aphids parasitize on currants only until mid-summer, after which the insects grow wings and move to neighboring plants. This is why weed control is so important. It is in their thickets that the aphid feels great and stays there until autumn, and then migrates back to the currant to settle for the winter.

This sucking pest deprives the shrub of strength and can lead to its complete death. The fact that the leaves are covered with multi-colored blisters is a manifestation of the plant's defensive reaction: currants are trying to restore tissue after insect bites. An additional harm from gall aphids is that it attracts ants to the site and often transfers various diseases from one plant to another.

The attack of the pest begins in the spring, as soon as the apical buds swell, but until the leaves with swollen bubbles (galls) bloom, it is not possible to detect insects. Following the leaves, young shoots undergo deformation. The twigs are curved, slowing down their growth. If you do not take action, the number of the pest increases rapidly and the currants are seriously damaged.

Fight against fungal diseases

Since both anthracnose and rust are fungal diseases, they must be dealt with using the same methods, using fungicides and some folk remedies. Due to the fact that red currants have a weaker immunity compared to other varieties, special attention should be paid to preventive measures. As soon as rusty spots appear on the leaves, and brown pads and yellow bloom have formed on the back side, treatment should be started immediately.

At the initial stage of the lesion, you can use formulations prepared according to folk recipes. Their advantages include affordability, low cost and environmental safety.

The following remedies work well in the fight against fungus:

• Garlic. To prepare the infusion, 1 glass of unpeeled cloves are crushed and poured with 10 liters of boiling water. The tool should be infused for a day. Before use, the infusion is filtered and 1 tbsp is added to it. spoon of "Green Soap" for better adhesion.
• Tobacco. The spray solution is prepared from 200 g of tobacco dust in 10 liters of hot water. After 12 hours, the composition is filtered and used for spraying. Each leaf must be carefully processed.

The treatment is carried out in dry cloudy weather; in case of rain, spraying will need to be repeated. Do not expect an instant effect from the use of folk remedies. It will take several treatments at intervals of 5-7 days.

In advanced cases, anthracnose on currants is treated using chemicals:

• copper sulfate;
• Bordeaux liquid;
• Topsin;
• "Captan";
• "Titanium".

For rust treatment use:

• “Cuprostat;
• "Copper oxychloride";
• Hom.

All drugs should be used exactly according to the instructions, in compliance with the dosage and the use of personal protective equipment. Treatments must be repeated three times: when the leaves open, during budding and after flowering.

As a precautionary measure, it is recommended:

• selection of resistant varieties;
• landing in a well-lit, elevated place;
• regular weeding and digging of near-trunk circles;
• the introduction of phosphorus-potassium fertilizers;
• timely thinning of the crown;
• scalding the bush with boiling water in early spring;
• disease vector control;
• disinfection of garden tools;
• preventive spraying.

Currant care needs to be adjusted according to weather conditions. The soil under the bush should not be too wet. Watering should be done in the morning, so that the soil has time to dry out a little before nightfall.

Destruction of gall aphids

In the initial stage of infection, when there are not too many insects, all infected leaves on the currant are cut off and burned outside the site. You can also wash off aphids with a hose. Due to their small size, pests will not be able to climb back and become prey for birds or predatory insects.

From the folk methods, fumigation of bushes in early spring with tobacco smoke or burnt rubber is used. The rubber must first be melted and placed in containers directly next to the bushes. Fumigation of tobacco is carried out using a smoker, which is usually used by beekeepers.

To get rid of the pest, you can use such means as soap solution (100 g per 10 l of water), tobacco infusion (300 g per 10 l of water) and formulations prepared on the basis of aromatic or bitter plants (wormwood, marigolds, onion husks), as well as needles. Plant raw materials in the amount of 200-300 g are poured with 10 liters of hot water and allowed to brew for 12-24 hours, then the shrubs are filtered and sprayed.

There are many chemical and biological preparations for aphids. Until the moment of flowering, you can safely apply insecticides based on pesticides, for example:

• Actellik;
• "Maxi";
• "Vofatox";
• "Calypso";
• "Confidor".

Closer to fruiting, it is better to use biological preparations based on natural ingredients for processing. In the fight against gall aphids, such means as "Avertin", "Aktofit", "Bitoxibacillin" have proven themselves well.

As a preventive measure, in early spring, red currants are treated with Nitrafen solution. It is necessary not only to spray the bushes, but also to cover the entire zone of the trunk circle. The solution should have a 3% concentration, an approximate consumption of 0.5 liters per adult plant.

It is advisable to plant calendula, marigolds, chamomile as scarers between currant bushes. For the same purpose, you can plant aromatic herbs, tobacco, onions and garlic. On the site, it is necessary to do timely weeding, paying special attention to the thickets of nettles, which the aphid likes to use for reproduction, laying eggs on the surface of the leaves.

The vulnerability of red currants to certain diseases and pests is not a reason to refuse to grow this tasty and healthy berry. At the first appearance of red spots on the leaves, the shrub must be treated. Timely implementation of preventive measures and proper care of the culture can completely save you from any trouble.