Powdery mildew on currants is one of the types of fungal diseases that affects berry bushes. The disease manifests itself in the form of a white-gray spotted bloom on young twigs, leaf stalks and on leaf plates. One of the main reasons for the emergence and development of fungi on currants is unstable weather with sharp temperature fluctuations and frequent rains. The mycelium of the fungus, for the time being in a state of remission, under such conditions begin to multiply rapidly, capturing more and more surfaces on young growths of currants.
Protecting currants from disease
Currant bushes are low, compact, very easy to care for and harvest. The fruits of black, red and white currants are healthy and tasty, they can be used to make excellent juices, compotes or preserves and jams. Currant leaves are suitable for brewing green teas - aromatic and unusual in taste drinks. For these reasons, many gardeners grow different types of currants in their gardens, but it is not always possible to get a good harvest from a berry bush if powdery mildew has appeared on it. It is urgently necessary, without waiting for the widespread spread of the disease, to take drastic measures to combat this disease, otherwise you can lose not only the crop, but also the plant itself.
Definition of disease
By biological definition, powdery mildew (ash or linen) is nothing more than a fungal disease of the currant, caused by the smallest spores of the powdery mildew fungus of the Erysiphales family. This family includes more than 700 species, united in 19 genera. For some reason, this disease, which manifests itself on plants, is also called "American powdery mildew" in Russia, with which it is not known exactly.
You should also not confuse the two concepts: powdery mildew or false. Today we talk only about the present form, downy mildew is rarely found on currants, it is caused by a completely different pathogen and its signs differ from the symptoms that we mentioned above.
It is worth noting that all types of powdery mildew fungus prefer to multiply on certain types of plants. A fungus that has settled on a currant does not transfer to an apple or pear; it will not move from cucumber leaves to tomato or eggplant bushes. Infection occurs on a family basis, that is, an apple tree from an apple tree (regardless of the variety), a pear from a pear, a currant from a currant, and so on are infected from each other.
Signs of powdery mildew disease of currants appear on plants in the same way, but it happens quickly. Gardeners yesterday did not notice any manifestations, but tomorrow the upper young shoots and leaves are already covered with a white bloom.
Important! At the first visible signs of infection, it is important to stop the further spread of the disease. Having noticed them, immediately proceed with the treatment, the methods of which we will discuss a little later.
- in the first stages of the disease, the leaves of young currant growths on the front side are covered with small whitish specks, as if the leaves were sprinkled with flour;
- then (in the absence of the necessary treatment) the spots become more and more enlarged, move to leaf petioles and twigs, currant leaves curl, shoots become thinner;
- the entire apical part of young growths twists into an ugly lump of dry foliage, the leaves fall, the petioles and branches become brittle, the growth of shoots stops;
- having destroyed the young parts of the plant, the fungus "occupies" the fruit ovaries and the fruits themselves, drying them up and turning them into hard balls, which also crumble to the ground;
- without receiving proper treatment during the season, the currants have to winter weakened and unprotected;
- many plants cannot withstand this condition and die from the cold or lack of nutrients, the flow of which to the currant bushes is completely blocked by the harmful overgrown fungus.
The top photo shows the state of currant leaves at the initial stage of their defeat by powdery mildew. In the video attached to this section, you can clearly see how infected currant bushes look compared to healthy plants.
Causes of occurrence
Let's move on to the next section of our article, for what reasons and why the infection of berries occurs, be it black, red or white currants. Experienced gardeners believe that the main reason for the spread of powdery mildew on the territory of the garden and vegetable garden is insufficient care of plants and violations of the technology of growing garden crops. If we add to such conditions frequent and sharp changes in air temperature during the day and night hours, heavy rains with rare sunny days, it will be just a "paradise" for fungal diseases.
Basic prerequisites for infection:
- The presence of a large amount of weeds on the site.
- Excess of planting density of currants in excess of the permissible technological standards.
- Excessive moisture in the soil and air (excessive watering or precipitation in the form of rain).
- Lack of moisture and nutrients.
- Big difference between nighttime and daytime thermometer readings.
- Lack of preventive measures to combat plant diseases and their pests.
Only by eliminating the presence of all these shortcomings, except for weather conditions, of course, which do not depend on a person, can we begin to carry out measures that contribute to the treatment of already infected currant bushes or measures that prevent the emergence of new foci on young growths of berry bushes.
Prevention and treatment
Most gardeners and gardeners keep their plots in perfect condition, they know that in order to grow any garden, fruit and berry crops, it is necessary to follow the planting technology, plant care and carry out preventive treatment against diseases and pests. Novice gardeners sometimes do not pay enough attention to these activities. We want to give some recommendations to young plant breeders who have no experience in gardening.
- It is necessary to constantly maintain cleanliness in the garden and vegetable garden, timely remove and mow the weeds, chop it up and fill it in the compost heap. Plant waste: fallen dead leaves and branches, spoiled and infected fruits of currants and other shrubs that have fallen on the ground, burn or dispose of in any other way.
- In spring, autumn and throughout the summer season, carry out preventive treatment of all garden plantings from harmful insects and various diseases.
- If you have just started laying your garden, then buy and propagate currant seedlings that are resistant to powdery mildew, there are plenty of such varieties on sale these days.
These first preventive steps will help keep the spread of fungal diseases on currants, such as powdery mildew in particular.
Methods of dealing with powdery mildew on currants and methods of treatment:
- at the first stage of the lesion, when whitish spots appeared on rare leaves and there are very few of them, you can get rid of them by removing them from the bush, cutting off and burning the remnants, then prepare the means for processing and immediately spray the currants, repeat the treatment after 7-10 days;
- if you missed such a moment or did not notice powdery mildew for 2-3 days, then the mycelium of the fungus during this time can cover a large area on the plant, in this case it is impossible to remove some parts of the currant without harming it. The plant must be immediately treated with chemicals 2-3 times at intervals of 7 days;
- Let's say that you have not had the opportunity to visit your garden during the summer, and the currant bushes are very strongly affected by powdery mildew, it is almost impossible to save them. There is one treatment that is risky but very effective. It is used by experienced gardeners to save valuable varieties of currant bushes. In early spring, they treat the plant with hot water, at a temperature not lower than + 70-80 ° C. There is a risk, but the plant would have died anyway, and with this method there is a chance to save the currant and give it a second life.
In specialized gardening stores there is a wide range of chemicals that help fight powdery mildew on any crops, you just need to choose the drug that effectively performs its functions.
Fans of environmentally friendly gardens who do not accept the use of chemistry can use folk remedies in the fight against powdery mildew, we recommend the recipe for one of them:
- Dissolve baking soda in water in a proportion of 3 tablespoons without a top for 10 liters of water warmed to air temperature (put a bucket on a sunny area),
- Dissolve 50 g of laundry soap in a small amount of water to the consistency of a thick slurry, add to the soda solution, mix everything thoroughly;
- you need to use the resulting product within 3-4 days, spraying all plants, starting from the tops;
- such treatments must be carried out 5 to 8 times per season, at intervals of 7-8 days.
You can find out about other folk remedies by watching the attached video clip, which describes many of the recipes for their preparation.
Gardeners who love their garden and all the plants that live in it will not allow even one single sprout to die from some powdery mildew. They are always ready to fight any misfortune in order to keep their green pets healthy. Taking a break from such a struggle in a shady gazebo, they will drink tea with currant leaves and a bite of blackcurrant jam and will be ready to defend their garden again. Let's wish them good luck in all their endeavors.