One of the favorite crops for landscape design is a maple - the owner of beautiful dissected leaves located on long petioles. However, all the decorative properties of the plant can be destroyed by powdery mildew.
What is powdery mildew?
Also called ash and white, it is a common fungal disease. It is characterized by a white coating on the leaves and deformation of the leaf plate. As the disease spreads, the maple leaves dry out and fall off.
Infection most often occurs in early summer. This time is the period of activation of the fungus after wintering. Hot weather, strong fluctuations in humidity and temperature weaken the maple's immunity.
How to protect crops from fungus? Protective measures should be taken in advance.
Prevention
The main preventive method to prevent powdery mildew from infecting a tree is proper care behind the maple:
- timely pruning;
- burning of plant debris that forms under the crown and is a wintering site for the fungus;
- balanced application of fertilizers (excess nitrogen increases the risk of damage).
It is not always possible to prevent infection; the only way to save a culture is treatment.
Treatment
There are several options for getting rid of fungus. Most effective method- spraying with biological and chemical fungicides - antifungal drugs.
These include Skor, Fitosporin-M, Falcon and many others. Treatment is carried out twice, with an interval of 2 weeks. The entire crown should be processed, which is not feasible for tall varieties (for example, Norway maple).
Less in an effective way is spraying with folk remedies - soda, laundry soap and other improvised substances. They do not guarantee a quick cure, but can be a temporary measure in the absence of chemicals.
Treating maple for powdery mildew- a long and thorough process, so it is better to prevent the appearance of fungus by regularly carrying out preventive measures.
Powdery mildew is a disease caused by various types microscopic powdery mildew fungi. It affects many crops, but although the symptoms of the disease (as well as the principles of combating it) are the same everywhere, each of the pathogens “specializes” only in one or several types of plants. Therefore, there is no need to be afraid that oak powdery mildew will spread to phlox, gooseberries or cucumbers. The fungus infects mainly young parts of plants: petioles, leaves, shoots, green berries. First, small spots appear on the leaves in the form of white plaque. When magnified, it is clearly visible that these are threads of a fungus - mycelium, which looks like a thick cobweb. It grows quickly, the spores easily break off from the chains and scatter in the form of a white powder similar to flour. The process continues all summer, and the germinating spores are undemanding to moisture, and the disease spreads even in dry weather. The concentration of spores in the air and the risk of plant infection constantly increase from spring to mid-summer. However, in most plants by this time the leaves are covered with a protective waxy coating - cuticle, and it becomes more difficult for fungi to penetrate living tissue. At the end of the growing season, small black dots become noticeable on the affected tissue - these are new fruiting bodies that have formed. They are able to tolerate unfavorable conditions, overwinter well on plant debris and on affected parts of plants, and germinate next spring when warm weather sets in. In spring, spores fly out of the mycelium bags and infect new plants.
Prevention of powdery mildew
- Mixed planting of unstable crops (phlox, roses, delphiniums), refusal of monoculture.
- Timely removal of plant debris and fallen leaves.
- Deep tillage of the soil for annual flower and garden crops, as well as between rows.
- Balanced feeding.
- From the second half of summer - reduce the dose of nitrogen fertilizers. During an outbreak of powdery mildew activity (usually late June - early July), it is better to feed plants with phosphorus-potassium fertilizers.
- The use of complex fertilizers with microelements, the introduction of wood ash. Foliar feeding with microelements.
- Regular watering - leaf resistance decreases during drought or due to insufficient watering (for example, caragana, common barberry, maple will get sick faster on sandy soil).
- Preventive autumn and early spring soil treatment in tree trunk circles with copper-containing preparations.
- Selection of resistant varieties.
Control measures
The development of powdery mildew can be suppressed by spraying plants with special preparations. Repeated spraying with fungicides is carried out after 10-14 days. For greater effectiveness, it is recommended to alternate medications. Please pay attention special attention trimmed hedges and plants at risk.
Risk group
You've probably noticed that young oak growths and shoots of trimmed hedges from species sensitive to powdery mildew, new maple leaves are almost always covered with a white coating. Indeed, plants that produce young growth and new leaves throughout the summer, when powdery mildew is most active, are more susceptible to the disease. The cuticle on adult leaves prevents the fungus from entering them. Weakened, soft or young leaves (growing back after pruning, shearing or due to intensive growth caused by increased fertilizing nitrogen fertilizers) are not as tough, they are less protected.
Severely affected by powdery mildew
Trees and shrubs:
. Barberry
. Birch
. Hawthorn
. Elder
. Elm
. Common oak (pedunculate) and many other types of oak (except red oak - its leaves are hard and dense)
. Caragana tree (yellow acacia)
Powdery mildew is a rapidly spreading fungal plant disease. Initially, a white powdery coating appears on the leaves, similar to flour or powder. It can be easily wiped off with your finger and even mistaken for ordinary dust. But that was not the case! Before you know it, this infection will appear again, and in greater numbers, capturing ever new areas of habitat. Not only the leaves become white, but also the stems and flower stalks. Gradually, old leaves turn yellow and lose turgor. New ones grow ugly and twisted. If measures are not taken to cure powdery mildew, the plant will die.
This is what powdery mildew deposits look like when zoomed in: 
Ulcers at the site of mycelium formation Powdery mildew disease: where does it come from?
- The weather outside is cool (15.5-26.5°C), damp (humidity 60-80%), cloudy (for example, during the rainy season). Weather conditions have a particularly great influence on outdoor and balcony plants; when grown in rooms they are not so noticeable;
- found in the soil large number nitrogen;
- plantings are thickened;
- The watering schedule is not followed. For example, a plant is often watered without waiting for the top layer of soil to dry. Or, on the contrary, they regularly dry out the earthen ball and then fill it with water. All this leads to impaired immunity and, as a result, the appearance of powdery mildew.
In addition to these external conditions, already “awakened” spores can end up on flowers:
- by air (from infected trees or plants);
- through irrigation water (if spores got there);
- through your hands (if you touched an infected plant and then touched a healthy one).
Powdery mildew can completely destroy a plant in a short time Proper agricultural technology is an important condition in the fight against powdery mildew
The fight against powdery mildew is an integrated approach. First, you need to put in order the agricultural technology for growing the affected plant. This means:
- watering only after the top layer of soil has dried;
- while fighting powdery mildew, completely stop spraying;
- if possible, move the affected specimen to a brighter, sunny place until the powdery mildew is cured;
- thin out thickened plantings, tear off old leaves that touch the ground;
- for the period of remission - less nitrogen fertilizers, more phosphorus-potassium fertilizers (in case of illness - no fertilizers at all).
All errors in care must be corrected, otherwise powdery mildew will appear regularly. Now let's talk about direct treatment.
How to fight powdery mildew: therapeutic spraying and watering
To get rid of powdery mildew, do the following:
- Tear off the affected (yellow, lacking turgor) leaves and all flower stalks. If powdery mildew appears on roses, petunias, chrysanthemums and similar bushy plants, it is advisable to carry out radical pruning. The more damaged branches are destroyed, the greater the chance of recovery;
- replace the top layer of soil in a container, pot or under a plant in a flower bed - entire colonies of mushroom mycelium are hiding there;
- carry out therapeutic spraying and watering of the plant with one of the medicinal preparations. When spraying, you should strive to wet all the leaves and shoots abundantly. The plant should pour like after a spring shower. There are more effective way: pour the medicinal solution into a basin and dip the bush into it. The soil is also generously moistened with the solution by spraying with a spray bottle or watering. The walls of pots and pallets are also processed.
Powdery mildew: folk remedies
Let's agree right away: folk remedies against powdery mildew are effective as a preventive measure or at the initial stages of the spread of the disease. If the destructive process started a long time ago, more than 5-7 days ago, it is already useless to fight in this way. It may be possible to stop the development of the disease, but not completely eliminate it.
The most famous and effective folk remedies Powdery mildew is prepared as follows:
1. From soda ash and soap
25 g of soda ash dissolved in 5 l hot water, add 5 g of liquid soap. Spray the plants and top layer of soil with a cooled solution 2-3 times at weekly intervals.
A protective preparation against powdery mildew is prepared from soda ash and liquid soap (preferably laundry soap) 2. From baking soda and soap
Dissolve 1 tbsp in 4 liters of water. l. baking soda and 1/2 tsp. liquid soap. Spraying is performed 2-3 times with an interval of 6-7 days.
3. Potassium permanganate solution
Dissolve 2.5 g of potassium permanganate in 10 liters of water and use it 2-3 times with an interval of 5 days.
4. Whey solution
The serum is diluted with water 1:10. The resulting solution forms a film on the leaves and stems, which makes it difficult for the mycelium to breathe. At the same time, the plant itself receives additional nutrition with useful substances and becomes healthier, which affects its improvement appearance. Treatment with whey solution is carried out in dry weather, at least 3 times, with an interval of 3 days.
5. Horsetail decoction
100 g of horsetail (fresh) are poured into 1 liter of water and left for 24 hours. Place on fire and boil for 1-2 hours. Filter, cool, dilute with water in a concentration of 1:5 and spray the bushes. The concentrate can be stored in a cool, dark place for no more than a week. Spraying with horsetail can be carried out regularly to prevent powdery mildew in the spring and summer. In the fight against an existing disease (in the initial stage), 3-4 times spraying every 5 days is effective.
6. Copper-soap solution
This remedy for powdery mildew is highly effective due to the inclusion of a well-known fungicidal drug - copper sulfate. 5 g of copper sulfate are diluted in a glass (250 ml) of hot water. Separately, dissolve 50 g of soap in 5 liters of warm water. After this, carefully pour the solution with vitriol into the soap solution in a thin stream and with constant stirring. The resulting emulsion is sprayed on plants 2-3 times with an interval of 6-7 days.
7. Mustard solution
Mix 1-2 tbsp into 10 liters of hot water. dry mustard. The cooled solution is good for both spraying and watering.
8. Ash + soap
Stir 1 kg of ash in 10 liters of heated (30-40°C) water. The solution is infused, stirring regularly, for about 3-7 days. Then pour the liquid component (without the ash suspension) into a clean bucket, add a little liquid soap, pour it into a sprayer and carry out the treatment. Spray the plants every day or every other day 3 times. Add 10 liters of water to a bucket with ash particles that have sunk to the bottom, stir and use it for irrigation.
9. Infusion of rotted manure (better than cow manure)
Fill the rotted manure with water in a ratio of 1:3 and leave for 3 days. Then dilute the concentrate twice with water and spray the bushes.
10. Garlic infusion
25 g of garlic (chopped) are poured into 1 liter of water, kept for 1 day, filtered and sprayed on the collection.
Powdery mildew: treatment with chemicals
If powdery mildew appears on your flowers, combating it is most effective with the help of modern fungicidal agents. They have a detrimental effect on the fungus, stop harmful processes in plant cells, protect and treat it. Spraying is carried out 1-4 times with an interval of 7-10 days (depending on the selected drug).
Chemicals for powdery mildew act quickly and effectively The most effective drugs for powdery mildew:
- Fundazol;
- Topaz;
- Acrobat MC;
- Previkur;
- Speed;
- Vitaros;
- Amistar extra.
A well-known fungicidal drug is phytosporin, the active ingredient of which is a concentrate of the bacteria Bacillus subtilis in a powder of chalk and humates. Despite the fact that phytosporin is considered a medicinal agent, it is practically useless against existing powdery mildew. However, as a preventive measure, it will work flawlessly.
Of course, not on everyone summer cottage you can meet! Many probably think that growing such a majestic beauty is simple, just plant it and water it on time - this is not at all the case. No matter what climate zone you decide to grow oaks in, you need to remember that the plant is prone to fungal infections and one of the dangerous diseases is powdery mildew.
What is powdery mildew?
You can determine the disease yourself. The surface of the leaves is covered with a faint gray-white coating, on which droplets of liquid gradually form. The shade of the plaque can be dark brown, then it resembles balls, the tone of which gradually changes to brown.
How to get rid of powdery mildew?
- Speed;
- Tilt;
- Byleton;
- Rayok;
- Thiovit;
- Jet;
- Topaz;
- But;
- Fundazim;
- Quadris;
- Fundazol;
- Topsin.
Along with chemicals, experts advise using biofungicides. Preparations made on the basis of biological microorganisms (live bacteria) capable of suppressing pathogenic microflora and blocking it further development. However, this method of treatment is not as effective as spraying with fungicides, but it is environmentally friendly. In this regard, the choice can be made on the following drugs:
- Planriz;
- Fitosporin-M;
- Integral;
- Mikosan;
- Pseudobacterin-2;
- Alirin-B;
- Gaupsin;
- Gamair.
Each drug is relatively inexpensive and its volume is sufficient for several treatments. How to use the substance is described in detail by the manufacturer on the packaging.
Traditional methods
Just yesterday it was difficult to get fungicides, and even more so biofungicides to combat powdery mildew. For these purposes, ordinary amateur gardeners used folk remedies. Today, you can also rid oak of fungal infections with solutions prepared on the basis of soda ash, laundry soap, wood ash, mullein, yogurt.
When choosing a method of treating oak, you should carefully examine the plant and correctly assess its condition and the degree of damage. If the tree is affected quite severely, then you need to choose more drastic methods of treatment - spraying with fungicides. If the fungus has affected only a small area, then you can try a less dangerous, gentle treatment.
To protect the garden without overuse chemicals, his enemies need to be “known by sight.” What is powdery mildew and how to combat powdery mildew? We will tell you about preventive measures and methods of control.
Powdery mildew is a disease caused by various types of microscopic powdery mildew fungi. It affects many crops, but although the symptoms of the disease (as well as the principles of combating it) are the same everywhere, each of the pathogens “specializes” only in one or several types of plants. Therefore, there is no need to be afraid that oak powdery mildew will spread to phlox, gooseberries or cucumbers.
The fungus infects mainly young parts of plants: petioles, leaves, shoots, green berries. First, small spots appear on the leaves in the form of a white coating. When magnified, it is clearly visible that these are threads of a fungus - mycelium, which looks like a thick cobweb. It grows quickly, the spores easily break off the chains and scatter in the form of a white powder similar to flour. The process continues all summer, and the germinating spores are undemanding to moisture, and the disease spreads even in dry weather.
The concentration of spores in the air and the risk of plant infection constantly increase from spring to mid-summer. However, in most plants by this time the leaves are covered with a protective waxy coating - cuticle, and it becomes more difficult for fungi to penetrate living tissue. At the end of the growing season, small black dots become noticeable on the affected tissue - these are new fruiting bodies that have formed. They are able to tolerate unfavorable conditions, overwinter well on plant debris and on affected parts of plants, and germinate next spring when warm weather sets in. In spring, spores fly out of the mycelium bags and infect new plants.
Prevention of powdery mildew on plants
- Mixed planting of unstable crops (phlox, roses, delphiniums), refusal of monoculture.
- Timely removal of plant debris and fallen leaves.
- Deep tillage of the soil for annual flower and garden crops, as well as between rows.
- Balanced feeding.
- From the second half of summer - reduce the dose of nitrogen fertilizers. During an outbreak of powdery mildew activity (usually late June - early July), it is better to feed plants with phosphorus and potassium fertilizers.
- The use of complex fertilizers with microelements, the addition of wood ash. Foliar feeding with microelements.
- Regular watering - leaf resistance decreases in drought or due to insufficient watering (for example, caragana, common barberry, maple will get sick faster on sandy soil).
- Preventive autumn and early spring soil treatment in tree trunk circles with copper-containing preparations.
- Selecting powdery mildew-resistant varieties
How to get rid of powdery mildew: measures to take
The development of powdery mildew can be suppressed by spraying plants with special preparations. Repeated spraying with fungicides is carried out after 10–14 days. For greater effectiveness, it is recommended to alternate medications. Pay special attention to trimmed hedges and at-risk plants.
Preparations for powdery mildew:
- Byleton,
- But,
- Quadris,
- Rayok,
- Soon,
- Tilt,
- Topaz,
- Topsin,
- Tiovit Jet,
- Fundazim,
- Fundazol.
There have been cases of the emergence of fungal races resistant to chemicals on some crops, so the development of varieties resistant to powdery mildew is an extremely pressing issue.
Risk group for powdery mildew
You've probably noticed that young oak growths and shoots of trimmed hedges from species sensitive to powdery mildew, new maple leaves are almost always covered with a white coating. Indeed, plants that produce young growth and new leaves throughout the summer, when powdery mildew is most active, are more susceptible to the disease. The cuticle on adult leaves prevents the fungus from entering them. Weakened, soft or young leaves (growing back after pruning, shearing or due to intensive growth caused by increased fertilizing with nitrogen fertilizers) are not so tough, they are less protected.
Severely affected by powdery mildew
Trees and shrubs:
Barberry
Birch
Hawthorn
Elder
Elm
Common oak (pedunculate) and many other types of oak (except red oak - its leaves are hard and dense)
Caragana tree (yellow acacia)
Horse chestnut
Maples different types, the most sensitive are the red-leaved forms of Norway maple (sycamore), Tatarian maple and ash-leaved maple
Hazel
Roses and wild roses
Rowan
Lilac
Currants and gooseberries
Apple
Ash
Herbaceous plants:
Cruciferous crops (except those with fleshy leaves, such as cabbage)
Common bluegrass
Cucumbers, pumpkins, tomatoes
Peonies
Phloxes
Chrysanthemums
Sage