Red spots on currant leaves: why do they appear and how to treat?
For many people who have a personal plot, currants are a royal shrub. And it is not surprising, because its berries are not only very tasty and fragrant, but also bring great benefits to the human body. To get a good harvest when growing this plant, it is worth giving it due attention and care.
In the summer season, gardeners may notice that red spots have appeared on currant leaves. If a person is experienced, then he will be able to quickly determine the cause and eliminate it. But the novice gardener will need to understand what caused this situation in order to immediately take action and save the plant.
Causes
For everyone who grows vegetables, fruits or berries, it is important to get a healthy and rich harvest. But in achieving this goal, some disease or uninvited parasite, from which the plants dry, can interfere. Often, in the warm season, currant foliage may have red bumps, brown and convex spots, growths. The defeat can be not only on red, but also on black currants. The reasons why these defects appeared can be very different, as well as their elimination.
Diseases
The currant bush often suffers from infectious and fungal diseases. We list the most common of them.
Septoria
Often this disease attacks blackcurrant bushes, the cause of everything is a fungus. In June, small brown spots with a red border can be seen on the leaves. In spring, this disease affects the shoots and fruits of the plant, which are also affected by brown swellings. During this disease, the foliage may fall off and dry out, the buds are not able to bloom. Accordingly, there is a significant decrease in yield. The infection persists in infected shoots and plant debris.
brown spot
It also refers to diseases of a fungal nature. In the hot season, the currant shrub is covered with spots with a brown color and irregular shape. These formations have a bright middle, over time their size increases, and the boundaries merge. The margin of the spot is a brown rim. The affected tissues are covered with a delicate brownish coating on both sides - these are the places where the fungus sporulates. If a severe infection occurs, the foliage dries up prematurely and falls off.
Brown spot is a disease that reduces the yield of shrubs several times. This infection is able to persist in infected plant debris.
Anthracnose
You can notice the manifestation of this disease when the flowering phase ends in the currant. The peak of the development of a fungal infection is considered to be July and August. Leaves are often severely affected, and anthracnose can also be found on petioles, young shoots and berries of the shrub. The onset of the disease is the formation of small bright spots that are isolated from each other. On each such defect there are glossy tubercles with spores.Over time, the spots become brown, and also, by merging with each other, form one large affected area.
Throughout the summer period, currants are attacked by several generations of this fungus. Petioles and young shoots are covered with gray-brown sores. New shoots do not form on diseased bushes, foliage falls prematurely, and weak yields are observed. The infection is able to persist in the cortex of the shoot, which is affected by the fungus, as well as the remains of the plant.
Terry
The causative agent of the disease is phytoplasma. It can affect black, red and white currants. For the first time, the disease progresses in the spring, its mass manifestation is observed approximately twelve months after infection. For a long period, the infection is in a latent phase, but at the same time it has the ability to infect other plants. Infected currants can be recognized by the presence of double flowers. A sick bush lags behind healthy ones in the speed of bud break, as well as flowering.
When terry, the currant has a deformed leaf, flower and shoot. The five-layer leaf becomes three-layer, it is small and asymmetrical. The affected shrub has a large number of shoots, they are short and thin. Currant completely loses the aroma that is inherent in it. Terry turns pistils and stamens into scales with narrow parameters and purple color. A double flower is unable to produce an ovary, and, accordingly, a fruit.
The infection can be transmitted with planting material and cuttings.
goblet rust
The first symptom of the disease is the appearance on the leaves of spots with a small size and dark red color. As the disease spreads, the spots increase in size and merge together.As a result, twisting and falling of the sheet occurs. If the plant is heavily infected, then the infection attacks the shoots, on which cracks become visible. The shoots break, and the currant dies. This type of fungus can also spread to berries. The disease begins to appear in June, and reaches its peak in mid-summer.
Pests
If the color of the foliage has changed on the currant bush, swollen brown blisters have appeared, then the reason may be in the attack of gall aphids. This is one of the most famous parasites attacking this plant. The most favorable period for its distribution is considered to be a hot and dry summer, especially after a warm winter. Wintering of eggs of this insect takes place on the branches of the bush.
After the buds open, a larva appears from the egg, which crawls to the underside of the young leaf. The vital activity of the larva is based on sucking juices from the plant, during which the leaves become covered with brown bubbles, their redness is visible even to the naked eye and at a long distance. The reverse side of the swellings is a depression. Over time, the leaves curl and die.
In the summer, after the growth process stops, the foliage coarsens. At this time, the female gall aphid begins to fly to other plants, where it continues its life process. Eaten at this time are not only currant bushes, but also nettles, peppermint, lemon balm, sage. At the end of the summer period, the harmful insect returns to the currant to lay eggs in order to repeat its life cycle next year.
But strawberry whiteflies can also cause deformation of the foliage on the currant.It does not look like dots, like aphids, but resembles a small white butterfly, which reaches a length of up to one and a half centimeters. The insect feeds on the reverse side of the leaf, by sucking the juices out of it. In the same place, females lay eggs, from which larvae with six legs emerge. The period of development of the pest takes about a month.
During the growing season, currants can be attacked about four times by new generations of whiteflies. The entire life process of the pest harms many crops in the garden. When a period of cold weather sets in, the parasite can hide under leaves or in the ground in order to comfortably overwinter.
If traces of damage are noticed on the shrub, as well as red spots, you should carefully examine the plant. When a strawberry whitefly is found, it is necessary to immediately begin the fight against an insect.
Control measures
Like any other disease or defect on a plant, the appearance of red foliage and brown swellings must be eliminated immediately. There are several ways to treat a plant, this procedure will depend on the cause of the situation. Time-tested folk remedies, high-quality chemicals and proper care will help bring currants back to life.
The most effective folk remedies that are aimed at combating harmful parasites, in particular gall aphids, include several remedies.
- Marigold tincture. Making it is easy. This plant must be dried and crushed in the amount of five liters. Flowers should be poured with boiling water in the volume of a bucket of water and insist for two days. Fifty grams of household soap must be added to the tincture, and after that it can be used for irrigation.
- tomato tops, infused with onion peel. To prepare the medicine, you need to take two kilograms of tomato tops and pour five liters of boiling water over it. This solution should be infused for two hours, then boiled for three hours. Next, the mixture is passed through gauze and diluted with water in a volume that is twice the medicine. After you need to take 0.5 kg of onion peel, pour it with two liters of boiled water and leave for two days. After that, two liters of water and liquid soap are added. Infused haulm and husks must be mixed and used as a sprayer.
- A decoction based on tobacco dust. To prepare it, you need to pour 0.5 cups of tobacco dust with a liter of water and boil for half an hour. After that, the mixture is removed from the fire, water is added to it in the original volume. It is necessary to insist the medicine in a dark place throughout the day. After straining, one teaspoon of liquid soap is added to the decoction. Further, it can be used to treat currants.
- Household soap tincture. To prepare it, you need to take 0.4 kg of laundry soap and dilute it in 0.4 liters of water. This tincture is worth treating the plant by spraying or rubbing the leaves.
- Infused white mustard powder. Ten grams of powder must be diluted in one liter of water and insisted for two days. Next, the tincture should be filtered. To spray a shrub, 0.2 liters of the drug is diluted in 0.8 liters of water and applied at work.
- Red pepper tincture. To prepare it, you need to take a kilogram of red capsicum, chop and put in an enamel bowl. One bucket of water is also added there and the tincture is boiled for an hour.After this process, the mixture should be insisted for three days and filtered. To spray currants, you need to take 0.15 liters of tincture and dilute with water.
To destroy aphids, there are many professional preparations. The use of Kinmiks, Karbofos, Aktara, Rovikurt, Vofatoks give an excellent effect.
In parallel, ants should be dealt with, which contribute to the spread of the parasite. Anthills located close to currants should be poured with boiling water. This method will destroy insects, but will not harm the plant itself and its roots.
To combat fungal diseases such as anthracnose, there are effective ways to help the plant return to its normal life process. In gardens where there are infected shrubs, it is necessary to carry out a number of measures to combat the infection.
- The affected bushes, which are covered with red growths, and the soil under the currant must be sprayed with Nitrafen or blue vitriol. It is worth carrying out the procedure in the spring, before bud break occurs.
- If the currant has already borne fruit, then you can fight the infection with the help of Bordeaux liquid. One hundred grams of the drug is dissolved in ten liters of water.
- Irrigation, in which colloidal sulfur, Kuprozan, is involved, will be a good way against diseases that the fungus has provoked.
- Be sure to remove the fallen leaves from under the bush and destroy it, as this is the place where spores of parasites and infections live.
Do not forget about digging the soil in the autumn and spring seasons.
The biological method is often used in the fight against diseases, it is based on the use of the drug "Fitosporin - M".This substance is distributed through the vascular system of the plant. The basis of treatment is the vital activity of spore cultures that make up the basis of the drug. "Fitosporin-M" neutralizes more than thirty types of infections. It has the ability to act at any temperature, weather conditions, as well as the life processes of plants.
How to process?
The effectiveness of folk remedies in the fight against aphids is observed only in the initial stages of the lesion. It will be necessary to process currant shrubs with folk remedies twice, observing an interval of seven or ten days. If insects attacked the shrub en masse, then the use of chemicals will be required.
Spraying with substances of a chemical nature must be carried out in early spring. The best moment will be the period when the buds have not yet opened, and the buds have not yet gathered. Processing is carried out in warm weather at a temperature not lower than eighteen degrees Celsius. It is difficult to give exact dates, because in different parts of the country the weather conditions are varied.
Thanks to spring processing, gardeners will have a chance to get a timely and rich harvest of healthy berries. It is at this time that an active process of vital activity of fungal infections and parasites occurs. Spraying in the spring will eliminate insect larvae and infectious agents. Proper treatment for pests and redness is carried out in this way:
- before bud break, the shrub must be doused with hot water at a temperature of eighty degrees;
- if there are overwintered eggs of the parasite on the currant, then it is worth irrigating with an eight percent solution of Nitrafen;
- while the foliage is growing, it is worth carrying out periodic treatment with "Decis" in dissolved form.
It is necessary to spray the bushes that the fungus has struck with Bordeaux liquid. The solution is prepared quite simply: one hundred grams of the drug must be dissolved in a bucket of water. This solution will be enough to irrigate three currant bushes. This procedure should be repeated after the flowering period of the plant ends, and berries are also collected. When treating a plant, do not forget about its possible addiction to the drug. After each subsequent treatment, the effect of spraying will be worse than the previous one, so it is important to alternate funds and replace drugs to combat reddening of foliage.
Some gardeners do not like to use chemicals to kill currant diseases. In such cases, there are several simple and proven methods that will eliminate goblet rust:
- soda solution - three tablespoons of liquid soap and two tablespoons of soda are dissolved in a bucket of water;
- manure infusion, which can be prepared from the third part of a bucket of manure filled with water;
- fermented milk product, for example, whey, kefir or sour milk, which dissolve in water one to ten.
Such spraying should be carried out in the evening and in cloudy weather.
Prevention
In order for your currant not to be attacked by gall aphids and other harmful insects, You can do the following preventive measures:
- regular destruction of weeds near the berry bush;
- preventive irrigation with a three percent Bordeaux liquid in early spring;
- spraying with insecticides before bud break;
- planting dill, parsley, cumin and cilantro near currants, thus insects that feed on pests will be attracted;
- planting chamomile, calendula or marigolds in close proximity to currants, which, with their strong aroma, can scare away aphids;
- destruction of anthills near shrubs in the garden;
- dousing the plant with hot water, which will destroy the eggs of parasites that have overwintered.
To prevent fungal diseases, the following measures should be taken:
- spray the plant with copper sulfate and Bordeaux liquid in early spring;
- before flowering, irrigate currants with drugs that stimulate the immune system, for example, Epin and Zircon;
- conduct proper and regular fertilization;
- pruning plants for sanitary purposes;
- in autumn, destroy the remains of foliage and dig up the near-trunk territory;
- after the harvest is harvested, it is worth spraying the plant with Bordeaux liquid;
- remove weeds and carry out thinning of plantings;
- plant currant varieties that are disease resistant, such as Victoria, Dutch Red, or Firstborn.
If you carry out these simple procedures, you can avoid the development of fungal diseases and attacks of parasites on currant bushes. Carrying out prevention is an opportunity to get a good harvest, protect the plant and save yourself the trouble of eliminating defects in the foliage.
Everyone who loves currants knows that this shrub is able to reward the owner with a good harvest of tasty and very healthy berries. This plant is characterized by unpretentious care, but problems with it can still arise.
Berry culture is often attacked by a parasite and a fungal infection, which is why you should not forget about timely prevention. If reddening of the foliage has already become noticeable on the plant, then the shrub should be treated immediately.
For information on what to do if red spots appear on currant leaves and an overview of pest repellents, see the following video.