Powdery mildew on maple. How to get rid of powdery mildew on oak

Norway maple is very popular in cities. But this tree has various diseases. Leaves are especially susceptible to infections. Pests are also very harmful to this tree. We'll show you how to get rid of them. Diseases and infections disrupt its normal nutrition and other physiological processes. The plant dies from a lack of substances and carbon dioxide, which it absorbs. The decorative effect of maple and its ability to withstand negative environmental factors suffer.

Powdery mildew and methods of dealing with it

The most common disease is powdery mildew. It looks like a white coating on the surface of the leaves, which appears in late May-early June. What is the treatment for this disease? Use an infusion of thistle field: pour 1 kg of green mass into 3 liters of water, leave for 8-10 hours.

Powdery mildew is a fungus in origin. If you see a white powdery coating on the leaves, you need to take action immediately. If this is done correctly, you will restore the health of your green spaces very quickly. Please note that at first powdery mildew is invisible to the naked eye on the surface of the leaves. Then the maple is covered with a white bloom and, despite normal watering, gradually begins to dry out. Using preventative measures is the most important thing you can do for a tree.

Powdery mildew spreads mainly in the first days of summer. Due to the wind, the fungus migrates from plant to plant and spreads very quickly. Not only maple is susceptible to infection, this attack can appear on oak and garden trees, especially when the summer is not very hot. The peculiarity of powdery mildew is that it tends to appear very high.

Powdery mildew does not pose a direct threat to humans. This fungus can cause enormous damage in the agricultural area. Powdery mildew can affect gooseberry bushes, currants and other berries. If sow thistle treatment does not help, you need to resort to spraying fungicides using hot mist technology.

black spot

Norway maple can also suffer from black spot. How does she look? Dark uneven spots on the leaves - its manifestation. As a preventive measure, spray with a 2% solution of foundationazole or copper sulfate and 300 g of grated laundry soap per 10 liters of water. This is done in early spring. And if the disease has already begun, then spraying with an infusion of onion peel helps.

black spot

Black spotting indicates a good ecology of the area. In addition to reducing the decorative effect, there is no harm from this disease. It is very important to create optimal conditions for the growth and development of maple, which increase the resistance of plants to diseases. Branches affected by diseases must be cut and destroyed. The same is done with the fallen leaves of the affected tree. You can carry out preventive spring spraying with fungicides.

Pests

The maple weevil is a common pest of both Norway maple (drummond) and Japanese maple. If the treatment of diseases is possible with folk remedies, then it is better to use special preparations to get rid of maple pests. Norway maple suffers greatly because the weevil destroys the leaves, and the tree may die. From pests, two drugs are most effective - they use 0.05% decis and inta-vir.

When another pest of the Norway maple appears - the maple mealybug, the leaves are sprayed with 3% nitrafen in cool weather. Garlic solution helps well (50 g of chopped garlic per 3 liters of water).

Some of the pests attack outwardly healthy trees (for example, caterpillars or leaf beetles), others (bark beetles) attack weakened ones. For leaves, caterpillars are dangerous. They damage the buds and flowers of Norway maple. Such an insect is, for example, the maple whitefly. The leaves just fall off if she settles on a maple. And sucking insects feed on the sap of trees and gradually lead to its drying (for example, scoops and ticks can be distinguished among this group of pests).

Less common insects, such as marble and June beetle, can also cause harm. Aphids are brought into the nursery along with sowing and planting material.

Ash shpanka is another beetle dangerous for wood, its characteristic feature is the mouse smell it emits. You can find eaten leaves, only the middle remains of them. The whole landing can be eaten out in a couple of nights. To prevent this from happening, you can use a tool called decis.

The false scab sucks the juice of the plant, which greatly weakens it. Leaves fall, branches die. To prevent this from happening, carry out prophylaxis with Admiral Ke.

Factors contributing to the appearance of pests

A significant role is also played by whether the maple is young or old. Plants of different ages "love" different pests and different diseases. Young plants are susceptible to attack by beetles, nutcrackers, flea beetles, elephants and cicadas. After closing the crowns, the maple takes a fancy to the goldfish.

Factors such as smoke and night lighting reduce maple's defenses. The fauna of maple pests in forest stands depends on the age of the stands. At a young and middle age, 10% of trees die off in maple and mixed stands. Young trees often die from May beetle.

To prevent the reproduction of pests, dead trees must be removed immediately. Proper care prolongs the life of maple.

Pests other than insects

Thus, the defeat of certain diseases depends on age, species and environment. It is in your power to preserve the beautiful appearance of the tree and extend its life. Both Norway maple and Japanese maple are a worthy decoration of the park and garden. In summer, it can serve as a great place to hide from the heat. In autumn, this tree pleases with a variety of leaf colors.

Powdery mildew, which is included in several of the most dangerous plant diseases, is also very dangerous for maples. Red-leaved maple forms are especially vulnerable to it. The appearance of powdery mildew can stop their growth, significantly worsen wintering, cause complete leaf fall and significantly deplete the plant.

Powdery mildew develops especially strongly in hot and dry years, with a lack of moisture in the soil and the presence of water drops on the leaves, for example, from dew or sprinkler irrigation.

What does maple powdery mildew look like?

Maple powdery mildew is ubiquitous. Especially often it occurs in case of violations of the technology of growing plants, excessive fertilizing, sharp fluctuations in temperature and air humidity. Maples in a state of stress are vulnerable to it, which is often found in urban plantations.

Most often, an “outbreak” of powdery mildew begins after sharp fluctuations in temperature, dew, cold rains.

The disease can manifest itself in all phases of plant development in the form of white powdery spots that appear first on the upper, then on the underside of the leaf. Then the white coating disappears, leaving a yellow spot in its place. Young leaves and tops of shoots are more vulnerable to powdery mildew, therefore, at first, powdery mildew can be found precisely on the tops of plants. With a strong attack, all leaves and stems are covered with plaque, turn yellow and dry out.

It is possible to distinguish powdery mildew from peronosporosis - downy mildew, a similar disease, first of all, by the fact that during peronosporosis, spots on leaves with a white moldy coating appear, first of all, from the underside of the leaves, and when affected by powdery mildew, they appear on top.

Powdery mildew pathogen and its biology

The bag spores of the fungus overwinter, which form on the mycelium at the end of the growing season, as well as the wintering mycelium. Their wintering takes place on the bark of shoots, fallen leaves, plant debris. With prolonged drops in temperatures below -25- (-27) ° С, the mycelium dies, therefore, in more northern regions with such frosts, or after frosty winters, powdery mildew is much less harmful. As a rule, powdery mildew begins to develop at high air temperatures, during the active growth of plant shoots.

As a rule, the development cycle of the pathogen from the spore to the leaf or inflorescence until the start of a new sporulation is from 3 to 12 days, depending on the temperature. The fastest development takes place at a temperature of 20-30 ° C.

Interestingly, although powdery mildew fungi thrive best in warm and humid weather, drought and decreased plant turgor, leaf binding, facilitate the penetration of haustoria into epithelial cells. Therefore, timely watering and sufficient substrate moisture is an important condition for the prevention of powdery mildew. At very low humidity, the development of the disease stops.

At the end of the growing season of plants, powdery mildew fungi form special wintering spores, however, they are easily destroyed in the soil by soil microorganisms.

Powdery mildew control measures

Plants receiving excess nitrogen nutrition, suffering from a lack of phosphorus, potassium and trace elements are more vulnerable.

How to get rid of maple powdery mildew?

The fight against powdery mildew on maple is systematic spraying with fungicides, starting with the appearance of a green cone. In conditions favorable for the development of the disease, spraying is carried out every 3-4 weeks. It is most reliable to carry out preventive spraying every 12-14 days, alternating systemic and contact fungicides. It's traditional Fundazol 16.50 UAH , Ridomil Gold 35.00 UAH , Topaz 22.00 UAH , copper-containing preparations, such as Medyan Extra 18.00 UAH . This group of fungicides is ideal for maple treatments in June-July, as well as for treatment of diseased plants.

Can be used in cold weather Champion 40.00 UAH Not available or Garth 52.00 UAH , and at temperatures above 20 ° C - Medyan Extra 18.00 UAH or Kuproksat 30.00 UAH Not available .

In general, the superficial location of powdery mildew mycelium allows you to effectively use contact preparations to combat it.

Additional treatments, for example, after cold rains, are carried out if the year is favorable for the development of the disease - there are sharp temperature fluctuations, dew often falls, cold rains fall. It is best to carry out such treatment without waiting for the first signs of the disease to appear, immediately after rain and a sharp cold snap.

In order to avoid the development of pathogen resistance to the drugs used, it is necessary to alternate different drugs effective against these fungi. Therefore, to combat powdery mildew of maple, alternatively, drugs such as Revus Top 36.00 UAH , Quadris 45.00 UAH . Sufficiently high efficiency was also shown by colloidal sulfur ( Thiovit Jet 36.00 UAH ).

For the prevention of powdery mildew, biological preparations, such as Trichodermin 94.00 UAH Not available , Fitosporin 12.00 UAH and its analogs, for example Phytohelp 12.00 UAH Not available and Mycohelp 24.00 UAH . However, their use is limited solely to the prevention of the disease - creating a "living film" on the leaf, they do not allow powdery mildew spores to gain a foothold and germinate. When a disease appears, their effectiveness decreases sharply, especially Fitosporin.

In addition, the exclusively contact nature of such preparations requires regular treatments every 5-7 days to protect new plant parts and “renew” the protective film on the leaves after rains.

The positive side of using biological preparations is that they have a very short waiting period, are safe for humans and can be used to treat maples located near fruit and vegetable crops during active fruiting of plants.

At the same time, the first treatment, at the beginning of shoot growth, can be carried out with effective systemic preparations, and then, regularly sprayed with contact preparations and biological preparations.

To improve the ventilation of trees and accelerate the drying of leaves, plantings are not allowed to thicken. Well-ventilated trees suffer from powdery mildew much less.

Feeding diseased plants

Increase the resistance of maples to powdery mildew by fertilizing with potassium and calcium fertilizers, which increase the tone of plant cells and strengthen cell walls. This makes it difficult for the feeding processes, the haustoria of the fungus, to grow into the cells of the leaf. At the same time, maples are very sensitive to the concentration of salts in the soil solution and do not tolerate chlorine-containing fertilizers well. Intensive fertilizing with nitrogen, massive application of nitrogen fertilizers, especially in the nitrate form, such as ammonium nitrate, also reduce the resistance of trees to powdery mildew. Therefore, they stop feeding with organic and nitrogen and spring complex fertilizers, and feed them Potassium sulfate 40.00 UAH(20 g/10 l), micronutrient chelates, calcium fertilizers such as calcium nitrate 44.00 UAH (15 g/10 l) or Brexil Calcium

Today I want to tell you how to deal with powdery mildew on plants. They do not always recognize it in time, mistaking it for ordinary dust, or do not attach importance to its danger to plants. Powdery mildew fungi cause this disease, they settle on leaves, stems, inflorescences, and literally drink all the juices, dooming their victim to death.

With the onset of spring, letters from readers began to come to my mail with requests for help. The season began and problems with plant diseases immediately began. Some of them are serious, but some can be cured very quickly if treated in time.

What powdery mildew looks like.

First, a white coating appears on the plants, small spots are not immediately noticeable. Soon they begin to grow and darken. A plaque that can be easily removed with your fingers is the spores of the powdery mildew fungus. Not immediately distinguishable, so it is dangerous. It spreads very quickly and in a couple of days the damaged leaves dry up and die.

How powdery mildew spreads:

• gusts of wind;
• on hands;
• a jet of water when watering;
• on garden tools;

The most interesting thing is that powdery mildew mycelium spores have their own “specialization”. That is, they do not move from one type of plant to another. In addition to the present, there is also downy mildew, their symptoms are somewhat different.

Where does the disease come from?

Spores are brought by the wind from diseased plants, or they live quietly in the soil and wait in the wings. And the hour is coming. Damp, cool weather, humid air are the most favorable conditions for the growth of mycelium. Thickened plants that lack air and sun are the first risk group for the disease, such, especially young ones, are often susceptible to and. And if you are also fond of applying nitrogen fertilizers, urea or ammonium nitrate, expect this trouble to visit your garden.

Very often powdery coating can be seen in greenhouses with cucumbers, where elementary irrigation standards are not observed. Summer residents, who rarely manage to visit the site, are especially affected. Plants stand dry for a long time, and then they are poured "for future use" with water.

Powdery mildew of apple trees, mountain ash, maples, oak, lilacs, hawthorn, roses, chrysanthemums, currants, strawberries, gooseberries, phloxes, wheat, cucumbers, cabbage, pumpkin, tomatoes affects. Houseplants often suffer from it too.

How powdery mildew develops.

When the spores wait for favorable conditions and hit the plant, they begin to form a mycelium, which, in turn, penetrates the surface of the leaf with its processes and sucks all the nutrients out of it. Gradually, the mycelium grows, drinking the blood juices from its victim. Soon it becomes like a plush blanket and completely covers not only the leaves, but also the stems. All vital functions of the plant are disturbed, because of the layer of mycelium, it cannot breathe and evaporate moisture, the photosynthesis mode is disrupted.

Eventually the leaves will die. The mycelium darkens and turns into black dots on the leaves. so he can successfully overwinter, and with the beginning of spring, again begin to infect everything around.

Powdery mildew prevention.

1. First of all, choose plant varieties that are resistant to this enemy.
2. Observe the order of planting, do not plant the same crop every year in the same place.
3. Weed out weeds in time, remove old or diseased leaves, thin out plantings;
4. If possible, observe the norms of watering, the main thing is regularity. do not water the plants in the very heat, cucumbers only with warm water, without falling on the leaves;
5. Do not be zealous with fertilizers, especially those containing nitrogen, in the second half of summer it is better to refuse them altogether;
6. Observe agricultural practices appropriate to the culture, powdery mildew prefers weak plants;
7. Be sure to remove old leaves and weed residues, dig up the soil in spring and autumn.

These elementary actions will save you a lot of nerves and time. It is better to prevent the causes for plant damage.

Fight against powdery mildew.

If you notice a white powdery coating on plants, you need to act as quickly as possible.

First, pluck off any infected leaves that have already begun to warp or are heavily covered with mycelium. In shrubs and fruit trees, cut off the affected shoots, try not to miss a single outbreak.

Secondly, when watering, do not get water on the leaves, remember that water is a carrier of spores. If the weather is damp, you need to reduce watering, in case of drought, on the contrary, water more often so that the plants do not weaken.

Thirdly, if possible, remove the top layer of soil under the diseased plant, all spores of the disease accumulate there. If this is not possible, treat the soil with a fungicide, sprinkle with wood ash or dry mustard.

Treatment of plants at an early stage of growth of the mycelium can be used folk methods of treatment.

1, In 10 liters of water, dilute potassium permanganate at the tip of a knife and spray the plants. Repeat the manipulation after 5 days. If necessary, you can repeat again.

2. Stir 2 liter cans of wood ash in a bucket of warm water and add 2 tablespoons of laundry soap grated on a coarse grater. let it brew for a week and strain. Spray plantings every 3 days.

3. We do, 5 g per glass of hot water (not boiling water). 50 g of soap, liquid can be diluted in 5 liters of water. Now, stirring constantly, we introduce a solution of vitriol into soapy water. We spray the plants from all sides, after a week the procedure is repeated.

4. Dissolve 3 tablespoons of ordinary baking soda in 10 liters of water and add 3 teaspoons of any liquid soap. Sprinkle this solution in a week, 2-3 times.

If the disease has already raged on the plants for more than a week, then we use "heavy artillery", fungicides. Fundazol solution is made according to the recipe, which is indicated on the package, depending on the culture. You need to spray the leaves, on the reverse side it is necessary, the stems, inflorescences, the soil around the plantings. Repeat the procedure after 10 days.

Timely measures taken can completely kill or stop the spread of powdery mildew on your site, in a greenhouse or on houseplants.
Now watch a useful video on how to deal with powdery mildew on cucumbers.

Diseases of plant leaves.

Poplar rust (Melampsora populina Kleb.).

Leaf disease of plants, the primary infection causes aecidiospores, which are formed on the leaves and needles of the intermediate host. The fungus develops inside the leaf blade. In summer (June), yellow or orange uredopustules appear on the underside; they form several times during the summer, which contributes to the infection of other plants. In case of severe damage to plants, uredospores can appear on the upper side of the leaf and on non-lignified shoots. Affected leaves turn black, curl and fall off; telitospores hibernate on them, which germinate in spring and infect the intermediate host.

spatial isolation between plantings of poplars, larch and pine; spraying trees for diseases (fungicides).

Birch rust (Melampsoridium betulinum Kleb.).

Leaf disease spreads on the underside of the leaf, orange pads of uredospores appear in summer, replaced by telitospores by autumn. Leaves turn yellow and fall off. The fungus hibernates on fallen leaves; in spring, larch needles, which are the intermediate host, become infected with basidiospores. Aecidiospores of larch infect birch. The disease causes premature leaf fall, delays growth and lignification of shoots.

Methods for combating plant leaf diseases: spatial isolation of birch and larch; spraying plants from diseases with fungicides.

Powdery mildew.

Powdery mildew usually affects young leaves or non-lignified shoots. Weakened plants are more likely to fall ill. Wet weather and warm summers stimulate the development of powdery mildew, but plant disease also develops in arid regions. Powdery mildew severely affects hardwoods: oak, birch, ash, fruit crops, etc.

Powdery mildew of oak (Microsphaerd alphitoides Grif).

Infection of leaves with powdery mildew of oak occurs with bag spores and vegetative mycelium. On the leaves affected by the disease, a white powdery coating appears on both sides, consisting of mycelium hyphae. Later, with the formation of conidia, the plaque becomes more dense and powerful. Mature conidia cause secondary infection of leaves and shoots with the disease. At the end of summer, fruiting bodies appear on the leaves - cleistothecia - brown, almost black, which overwinter.

In diseased plants, the content of chlorophyll decreases, the process is inhibited photosynthesis, respiration (gas exchange) and transpiration are disturbed. Shoots do not ripen well and are often beaten by frost.

Methods for combating plant leaf diseases: destruction of fallen leaves in plantations that are a source of infections; when the first signs of the disease appear, it is necessary to spray the plants against diseases with fungicides, spraying the plants against powdery mildew is carried out after 10-15 days several times during the summer; systemic drugs are the most effective.

Maple powdery mildew is caused by the fungus Uncinula aceris Sacc. A white powdery coating appears on the affected leaves due to the growth of the mycelium. Infection with the disease occurs in summer with conidia, in autumn brown cleistothecia appear.

Methods for combating plant leaf diseases: the same as with oak powdery mildew.

Powdery mildew of apple and pear (Podosphaera leucotricha Salm.) sometimes appears on leaves, shoots and flowers in early spring in the form of a white bloom. Leaves turn brown, curl, flowers fall. The fungus overwinters on shoots and fallen leaves.

Methods for combating plant leaf diseases: spraying apple and pear trees with fungicides in spring.

Leaf spots.

Leaf spot disease of plants is caused by various phytopathogenic fungi, bacteria, viruses, as well as adverse environmental factors. Separate parts of the tissue die off, the color, structure, shape change, i.e. various spots appear.

White leaf spot of poplar (septoria).

This plant disease is caused by the fungus Septoria populi Desm. In summer, small light gray, sometimes white spots of various sizes with a reddish-brown border appear on the leaves. On the surface of the spots there are black dots - pycnidia of the fungus. Conidia ripened in pycnidia are carried by wind, water and infect leaves.

Methods for combating plant leaf diseases: collection and composting of fallen leaves; spraying plants against diseases in early spring with eradicating fungicides, as well as spraying plants during the growing season.

Black spotting of maple leaves.

Maple leaf black spot is caused by the fungus Rhytisma acerinum Fr. In the middle of summer, light spots appear on the leaves, black ones appear in autumn. resinous spots with a yellow border. They form conidia. On the fallen leaves, marsupial sporulation is formed - apothecia, which are the source of infection, so the fallen leaves must be burned.

Methods for combating plant leaf diseases: the same as with white spotting of poplar.

Red-brown spotting of sweet cherry (coccomycosis).

The causative agent of the disease is the fungus Coccomyces hiemalis Higg. It affects the leaves and stalks of sweet cherries and cherries, to a lesser extent apricots, plums, cherry plums. Dark red angular spots appear on the upper surface of the leaves. Leaves turn yellow and fall off. Fruit quality is deteriorating. Pink conidia appear on the underside of the leaf and infect other leaves. The fungus overwinters on fallen leaves.

Methods for combating plant leaf diseases: destruction of fallen leaves; in early spring, before the buds swell, eradicating spraying of fruit trees; spraying fruit trees in summer with fungicides; repeated spraying of fruit trees with fungicides after 10-15 days; in the nursery 6-7 treatments of fruit trees during the growing season.

Willow scab.

The causative agent of willow scab is the marsupial fungus Venturia chlorospora (Ces.) Wint. In the spring, the affected leaves wither, blacken and die. The disease passes from dead leaves to the shoot, causing its deformation and blackening. Conidia of the fungus, formed near the veins of dead leaves, are the source of infection. The fungus overwinters on fallen leaves. Wet weather in spring and summer stimulates the development of the disease.

Methods for combating plant leaf diseases: cutting and destruction of affected shoots, destruction of litter; early spring spraying of trees willow fungicides; in summer, when the first signs of the disease appear, it is necessary to re-spray willow trees.

Apple scab (Venturia inaequalis (Cooke) Wint).

Apple scab affects leaves, cuttings, stalks, flowers, shoots and fruits. A green-brown coating of sporulation of the fungus appears on the leaves, scaly spots on the shoots. Affected leaves and imported apple trees fall off, shoots die off, fruits crack. The fungus overwinters on fallen leaves and becomes infected in the first half of summer.

Methods for combating plant leaf diseases: destruction of fallen leaves; early spring spraying of apple fruit trees before buds swell; spraying apple fruit trees during the period of isolation of buds, in the phase of a pink bud and after flowering as the disease develops; with severe damage to fruit trees, apple trees carry out several treatments with fungicides in 10-15 days.