With the arrival of summer, the darlings of florist roses are virtually defenseless in front of one of the most common diseases - powdery mildew. Low night temperature, lack of light in thickened plantings, lack of or excess of certain trace elements in the soil lead to the fact that the bushes are affected by a dangerous fungus. If you let it go, the disease can cause a lot of damage to the color queens.
The control of powdery mildew on roses depends on the stage of the disease and the area of damage. If the disease only manifested itself and captured a couple of bushes, it is more expedient to use folk methods. But with the large-scale nature of the defeat, they may not work. In this case, you will need more serious means, popularly called "chemistry".
Folk recipes against powdery mildew
At the initial stage of the appearance of white bloom on roses, bushes can be sprayed with one of the solutions to choose from:
- soda-soap solution (50 g of soda and the same amount of soap on a bucket of water)
- garlic infusion (80 g of crushed cloves brew in 10 liters of water),
- mustard infusion (2-3 tablespoons of powder per 10 liters of warm water),
- solution based on serum and iodine (1 l and 10 drops, respectively, in a bucket of water).
Spray roses should be in the evening with a fresh solution at least twice. Infected leaves and flowers are pre-cut and burned.
Chemical control measures
If the time of onset of the disease is missed or many bushes get sick, it is better to take special preparations. Powdery mildew copes with fungicides such as:
When treating roses with fungicides, one should maintain an interval of 2 weeks and alternate the means so as not to cause addiction.
To prevent the occurrence and development of dangerous fungus, it is necessary to regularly carry out preventive measures:
In addition, it is important to choose a well-lit and non-windy place for them at the stage of planting seedlings, and to leave a sufficient distance between the bushes when breaking up the rose garden.
The origin of powdery rose
The rapid development and spread of powdery mildew is due to the fact that this disease is caused by ectoparasitic (living on the surface of the plant) microscopic fungi. The fungus that settles on the rose is called the “sphere of a panel”. Its spores persist for a long time in the soil, so infection usually begins with old lower leaves and quickly rises to buds.
White bloom, externally similar to flour, is the mycelium (mycelium) of the parasite. After maturation of a new generation of spores on the mycelium, droplets of liquid appear, resembling fine dew. The rose, completely covered with a mealy bloom, will have to be careful not to spread the spores, remove it from the soil and burn it, and treat the rest around the plant with means of protection. But if the disease is “caught” at the very beginning of its development, roses can be saved.
Strategy to combat fungal infection
For the successful treatment of roses from fungal diseases, it is necessary to know that the parasite's mycelium has unlimited access to food and is growing phenomenally fast. However, his body is not located inside the organs of the plant, but outside, therefore it is sensitive to the moisture content in the air. The action plan is as follows:
- The affected shoots of roses are cut to the maximum and burn all cut.
- Remove leaves touching the ground.
- Healthy bushes are thinned out to enhance the natural airing of the landings.
- Topsoil, probably containing spores, is replaced by fresh.
- Garden roses are abundantly sprayed with a fungicide, pottery roses are fully immersed in the fungicide solution. The treatments are repeated as many times as indicated in the instructions for the selected drug.
Council During the period of the fight against fungal infection, stop the nitrogen supplements, but strengthen the forge-potassium fertilizer - this will increase the immunity of the plant.
Chemistry in the fight against fungal plaque
The most effective means of treating fungal infections on plants are copper and sulfur preparations. And if we are talking about powdery mildew, then colloid sulfur and ash solution are ideal. Some rose lovers try to use Bordeaux liquid and even antibiotics, such as tetracycline, but extensive floriculture experience shows that they are ineffective.
The list of chemical preparations for the rescue of roses from the powdery mildew includes (in brackets the amount of the drug per bucket of water is indicated):
- colloidal sulfur (50 g): sprayed up to 4 times per season at the rate of 3-4 liters. on 50 sq.m,
- copper sulfate, it is copper sulphate (10 g): it dissolves only in warm water,
- Swiss "Tiovit Jet" (30-40 g) and "Kvadris" (120 ml),
- Prognosis concentrated emulsion (10 ml)
- "Fundazol" (10 g),
- "Topaz" (8-10 ml).
Before using the fungicide, carefully read the instructions, find out how to prepare the working solution, how to dilute it, how many times it is roses that are processed. Work is carried out in thick clothes, gloves, it is desirable to use safety glasses. During processing in the rose garden should not be children and pets. To preserve the bees as much as possible, spraying is carried out at sunset, when insects have finished circling the flowers.
Getting rid of the misfortune of folk remedies
Abroad, milk (or whey) is considered the best folk remedy against fungi on roses. It contains proteins that, when exposed to light, destroy the mycelium of the fungus. Milk is diluted with water at a ratio of 1: 2 and once a week, the plants are literally “poured” in order to drip from them. Given the principle of the drug, the treatment is carried out in sunny weather and in the morning.
Ash solution is prepared from 1 kg of furnace ash and a bucket of water. For the "sticking" of the liquid to the leaves of the rose, half a cup of rubbed soap is added to the solution. The solution is insisted for 3-5 days and is certainly filtered so that the ashes do not clog the spray nozzles. Dry ash is recommended to mulch the soil under the roses.
There are such popular measures to combat fungi, as solutions:
- iodine (20 ml per bucket of water),
- potassium permanganate (2 g),
- onion peel (200 g) - pour boiling water, insist 2 days.
Folk remedies are weaker than chemical ones; therefore, the use of them is observed no later than 2-3 days after the onset of the initial symptoms. They are also ideal for preventing infections, because they are absolutely safe.
Mealy dew on your favorite roses - a reason to think about the right agricultural techniques. Regular examination of bushes, the fight against thickening, preventive measures, the selection of resistant varieties will help to cope with an unpleasant disease.
What is powdery mildew dangerous?
Powder-growers, gardeners and flower growers very often collide with powdery mildew, as it affects garden, grain, fruit and berry and ornamental crops.
This fungal disease is caused by a number of pathogenic fungi. If we talk about roses, then a mushroom settled on them called “Sphaerotheca pannosaLew. var. Rosae Voron. As a result of its settlement on the leaves, stems and buds of flowers, the plant loses its decorative appearance, stops growing, its buds deform, do not open, the leaves turn brown, turn black and dry out. As a result, the death of the flower can be observed. Even at the initial stage of the disease greatly reduces the immunity of plants, and they can not tolerate adverse external conditions, winter cold.
Signs of defeat
The symptoms of powdery mildew are quite characteristic: they do not confuse this disease with any other. With the defeat of the organs of plants covers the mealy cobwebby grayish-white thick plaque - mycelium. It looks like it looks like flour is poured on the sheets. After spores ripen, drops can be observed on the plaque - it is from here that the name of the disease originated. Later, at the end of summer, the bloom becomes brown, and on the surface of the leaves, stalks, small dark brown balls appear - spores.
Usually, infection occurs in the first month of summer - it is at this time that the spores of the fungus, which had hibernated in the fruit body on plant debris, are released. It begins with the lower leaves, gradually capturing the entire flower.
Favorable factors for the spread of the disease are heat, high humidity, sudden changes in temperature during the day and at night. Usually, temperatures from 22 ° C and above are sufficient and air humidity is 60-90%. There are several reasons for the spread of the disease on roses:
- planting infected seedlings,
- wrong agrotechnology,
- thickened landing,
- a surplus of nitrogen fertilizers,
- nutritional deficiencies, in particular phosphorus and potassium,
- lack of preventive measures
- the presence of weeds in the rosearium,
- poor air permeability.
Of course, as with any disease, it is better not to allow it than to deal with its consequences. Therefore, preventive measures take the first place in the cultivation of roses. These include:
- regular inspection of plants
- compliance with the recommended conditions for planting (drainage of soil, sufficient distance between the bushes, the choice of the site with the right lighting, landing on an open area, protected from the winds),
- timely removal of weeds,
- proper agricultural practices, including regular watering and compliance with the rules for the introduction of nutrients - do not overfeed with nitrogen and prevent deficiency of phosphorus and potassium, prefer to give organic feedings,
- prophylactic spraying with special protective preparations
- careful autumn rosemary processing with the cleaning of dry foliage and deep digging of tree trunks,
- Choice for planting disease resistant varieties.
- "Leonardo da Vinci".
- "Wedding Bells".
- New Dawn.
- "William Shakespeare 2000".
- "Rosters Yuterson".
Also used are 0.25% Benomil, 0.4% Zineb, 0.1% Fundazol. As a rule, treatment is carried out in the spring before flowering and in the autumn after dropping the foliage, the interval between spraying is 10-14 days.
The root-dressings are also measures for the prevention of powdery mildew, which should be carried out before flowering using a mixture of superphosphate (0.3%) and potassium nitrate (0.3%).
How to determine powdery mildew
The symptoms of powdery mildew are too obvious to be confused with other fungal diseases. How this disease looks like speaks its name. The plant appears to be sprinkled with flour or drenched in milk. The leaves are covered with white and gray bloom. This is the mycelium. When spores ripen, droplets of liquid appear on the raid, similar to dew. In the people, this disease is also called: pepelitsa, torture, belle.
The disease is caused by spores of the fungus with the scientific name Sphaeroteca pannosa. Infection occurs at the beginning of summer. At this time, they are released after wintering in various plant debris. And they begin their destructive work with the lower leaves of the bush, gradually rising up.
They like warm, rainy weather with a significant difference in temperature during the day and at night. All this is characteristic of the first summer month. The disease is actively developing in thickened plantings, and is transferred from plant to plant by wind, pests and insects.
Treatment of folk remedies
As long as the fungus does not germinate in the internal tissues of the plant, you can try to fight it with traditional methods. The main thing - do not miss the beginning. Constantly inspect the bush. At the first sign, remove affected areas.
It is good if you can restrict yourself only by folk methods. Still, in comparison with chemical they do less harm to the environment. Less dangerous for you, for bees and birds. Do not kill the beneficial microorganisms in the soil and do not deprive it of fertility.
When spraying them follow the general rules of preventive treatments:
Choose dry, calm weather for treatments.
If immediately after spraying rain, then repeat it when the leaves dry.
Spray the plants in the evening, but so that they have time to dry before night.
Prepare the solution as much as needed for one treatment. Keep it is not necessary.
- serum - 1 liter,
- water - 10 liters.
It is necessary to carry out three treatments every three days, observing the general rules of spraying.
Or prepare a solution of whey with the addition of iodine:
- serum - 1 liter,
- iodine - 10 drops,
- water - 10 liters.
The treatment is carried out twice. The interval between procedures is a week.
- soda ash - 25 grams,
- liquid soap - 5 grams,
- hot water - 5 liters.
Soda pour water, add soap, everything is well mixed. The solution is cooled. Spray them plant and the ground under it. Spend 2 treatments with an interval of 7 days.
Instead of soda ash can be used and food. Then the composition of the solution will be as follows:
- baking soda - 1 tablespoon,
- liquid soap - 0.5 tsp,
- water - 4 liters.
This means is sprayed with a rose three times, with an interval of seven days.
If you are late with treatment, folk remedies will not help. It is necessary to move on to fungicides - specially developed drugs to combat fungal diseases.
They are of two types:
Chemicals are more dangerous for you and the environment. But they are effective, especially fungicides of systemic action. They penetrate the plant tissue and kill the pathogen there.
Biofungicides are not dangerous to nature. On the contrary, there are those that improve the fertility of the soil. But their effectiveness in combating diseases is low. They are good for preventive purposes, to strengthen the plant. They are sometimes used as growth promoters.
The active substance of this drug is soil bacteria that are in a dormant state. Before its use, they must be activated, otherwise the drug will be useless.
Phytosporin is produced in the form of:
The drug in vials is usually used for indoor plants. But the powder and paste must be prepared for use.
You can not take water to dissolve the powder or paste just from the tap. It may contain chlorine. He kills bacteria. Therefore, water must be defended. Or take rain, well, boiled, thawed.
When diluting the powder with water, the resulting mixture should stand for three hours. During this time, the bacteria will wake up and start work.
Dilute the paste several days before spraying.
For better adhesion of the solution, add one teaspoon of liquid soap to a ten-liter bucket of water.
The working solution from the powder is prepared in the ratio of 1 part of phytosporin + 2 parts of water. Therefore, it quickly ends, and every time it is necessary to direct a new one.
Paste is more economical and convenient to use. It is dissolved in water in the same ratio, but it is a concentrate. It can be stored all season and diluted with water before use, as well as added to other spray solutions.
The foliar treatment of the plant for medicinal purposes is carried out every two weeks in dry weather, and in rainy weather once every seven days.
For the prevention of fungal diseases (powdery mildew), rose bushes are sprayed at the beginning and at the end of the vegetative season.
Doses of powdery mildew treatment:
- powder: 10 grams of substance + 5 liters of water, repeated every two weeks,
- paste: 3 teaspoons of substance + 10 liters of water, repeat every two weeks.
This biological fungicide is available in three types:
Active ingredient - soil bacteria. As a result of their vital activity, the growth of pathogenic microorganisms is suppressed.
The protective effect after the use of this drug lasts for two weeks. To achieve the best result, they need to process the plant and the soil.
For spraying the solution is prepared as follows:
- tablets - 2 pieces,
- water - 10 liters,
- liquid soap - 1 ml.
Liquid soap is added as desired. Its purpose is to provide a better fixation of the solution on the plant. To stimulate growth, many growers add Epin or Zircon.
If you are going to use the drug not for treatment, but for prophylaxis, then the indicated doses should be halved.
This is a systemic drug. The active substance in it is benomyl. It penetrates the plant tissues and prevents the pathogenic fungus from multiplying there, since it loses the ability to divide the cell nucleus under the action of the foundation substance.
This drug, unlike biological agents, is not afraid of low temperatures. It can be called all-weather.
The spectrum of its action is wide. It is not only capable of fighting with powdery mildew, but also destroys harmful larvae, insects, worms.
It comes in the form of a white powder. The smell is unpleasant, but weak.
The disadvantages of the foundation are the same as for all chemicals:
- parasitic fungi develop resistance to it,
- it is dangerous for the environment and man.
In the treatment of powdery mildew on roses, it is necessary to carry out a threefold treatment with a base solution. При приготовлении раствора берут 10 г вещества и 10 литров воды.
Это тоже системный препарат. Действующее вещество — пропиконазол. It affects the ability to multiply parasitic fungi, therefore, stops the development of the disease.
Available in the form of a concentrated emulsion. This tool very quickly penetrates the plant tissue, so it is not afraid of rain. Two hours after treatment, he is already in the plant. The protective effect of the drug lasts two weeks.
It can be used at air temperatures of less than thirty degrees.
Provide the necessary conditions when landing
Buy seedlings of roses only in specialized stores or nursery. Do not trust the market, then not to be disappointed.
The purchased seedling must be healthy, well developed, have at least three shoots.
Ask about his age, which group is grafted or rooted own.
In the spring of roses can be planted until the end of May. In autumn - the deadline is October 20. And sometimes before, it all depends on the weather.
If you can not immediately plant a sapling, then to save it, wrap the roots with a damp cloth, and the whole bush with a damp newspaper, put it in a plastic bag and tie it up. Now it can be stored in a cool place for up to ten days.
Dig a hole for planting seedlings in accordance with the size of the roots. It should not be deep and very wide. Dig it so that it can straighten the roots well.
Put compost mixed with earth on the bottom of the pit. Put a seedling in it. Spread the roots. Fill with earth so that the grafting site is buried by 3-5 cm. If it is deeper, the grafting site falls into the cold layers of the soil. From this rose grows poorly. If it is planted higher, dicky will actively begin to grow. Then it will be difficult to get rid of them.
Then the rose should be poured abundantly. After that, spud up to 15 cm. When the buds begin to grow, unravel. If the rose landed in the fall, then razukochivat not necessary.
Try to plant roses in a place well lit by the sun. But not on the south side. Pests will attack her there. Climbing roses should be planted in a well-ventilated place. Ideal to plant on the east or west side of the house.
Inspect roses regularly
In order for the rose not to hurt, it must be regularly examined. So you can see the first signs of powdery mildew. Carefully inspect the stems, leaves on both sides, buds, flower petals. If you notice the affected parts of the plant, remove them immediately. And then spray the plant itself with a fungicide.
Remove weeds and fallen leaves
The soil around the rose bushes should always be free from weeds and fallen leaves. If they are not removed in time, they will become a source of rose diseases. In the fallen leaves winter pathogens of fungal diseases winter, in particular - powdery mildew. Cut off the diseased leaves immediately remove. This will prevent further spread of the infection.
During the cutting it is necessary to disinfect the instrument. Otherwise, you yourself will transfer the disease from a sick plant to a healthy one. For disinfection, you can use any alcohol or chlorine-containing agent available to you. Just do not heat the tool. From it its cutting part spoils, quality of metal changes.
Do not overdo it with nitrogen fertilizers.
The fact that you overdosed with nitrogen, you can easily understand by the abundance of mighty rose stalks and dark green leaves, a small number of buds, late flowering. Such a plant becomes a treat for aphids. She colonizes him. All this taken together is a direct path to the occurrence of fungal diseases, powdery mildew as well.
Provide enough potassium and phosphorus
Nutrient deficiencies can be a triggering factor for powdery mildew on roses. In particular, potassium and phosphorus. It is these macronutrients that are responsible for strengthening the plant immunity, its immunity to fungal diseases, the development of the root system, and resistance to low temperatures. Therefore, we must strictly observe the schedule of dressing.
During the season you need to spend three mandatory feeding:
The first - in April, when the plant wakes up after winter. During this period, the rose requires more nitrogen, and phosphorus and potassium in the same proportion. For feeding you can use any complex mineral fertilizer. Pay attention only to the proportional ratio of the components. A few days after the mineral dressing, apply organic fertilizer (mullein infusion). This will improve the structure of the soil.
The second - while tying the buds. The proportion of nitrogen fertilizers is decreasing, while the share of potash and phosphate fertilizers is greatly increasing. The principle of introduction is the same as in the first case.
The third - after the first flowering. From nitrogen fertilizers refuse, feed only phosphate and potash.
Spray roses with protective preparations.
To prevent the appearance of powdery mildew on roses, perform preventive treatment of the bushes with fungicidal solutions. For prophylaxis, you can use biofungicides, such as phytosporin. Be sure to treat them in early spring, before the buds are moved, as well as before wintering shelter. During the growing season, you can use folk remedies, sprinkling roses every two weeks with soap and soda solution or whey.
In the autumn, clean dry leaves and dig the soil.
If you do not remove dry foliage under the rose bushes and do not dig up the soil under them, then the spores of the causative agents of fungal diseases will safely survive the winter. You will cover the roses, the leaves will start to scream, parasitic fungi there are nice and cozy. Why, because of their laziness to ruin the roses? When removing leaves, do not put them in compost. They can infect him. It is better to burn the leaves.
Initially choose powdery mildew resistant varieties
When choosing a rose for planting in your rose garden, pay attention to its resistance to powdery mildew. Do not blindly trust the seller. Look in the directory, chat on the forums. Only then decide on the purchase of a new resident.
Experienced growers advise these varieties:
- Purple tige (Purple Tiger),
- Hot chocolate,
In the case of powdery mildew, “to diagnose” is not difficult, since it has a number of characteristic signs:
- the upper part of the leaf plate, the stem, the buds and the petals of the blooming flowers are covered with a mealy white or light gray patina,
- upon close examination, the stains look like the thinnest layer of cobwebs or cotton,
- yellowness and necrotic spots appear on the leaves,
- rose bushes slow growth, buds shrink, some do not open at all.
When looking at the roses struck with powdery mildew, it seems as if the flowers are sprinkled with flour or sprinkled with a solution of lime. If there are such associations, then 100% flower garden captured harmful fungus.
A pathogenic organism feels best at air temperature of + 15 ... + 25 ° С and humidity of 60-75%. Therefore, the rapid spread of infection occurs from early July to early September.
At the first symptoms of powdery mildew on roses, you must begin treatment with folk remedies. Here are some effective recipes.
Recipe 1. Whey (1 l), iodine (10 drops) mixed in water (10 l). Use for spraying the leaves and stems twice with an interval of 7-10 days.
Recipe 2. Soda (40-50 g), soap (40 g) mixed in 10 liters of water. Spray twice a week.
Recipe 3. Fresh manure (one third of the bucket) pour water (10 l). To sustain three days, stirring every day. Strain through cheesecloth. Dilute with water 1 to 10.
Recipe 4. Chopped garden weeds (half a bucket) pour a bucket of hot water. Stir and defend for two days. Before use, strain. Dandelions, celandine, coltsfoot, plantain and other herbs will do.
Recipe 5. Finely chopped garlic (80 g) put in 10 liters of water, boil. Cool the solution, strain and use for spraying.
General recommendations on the treatment of folk remedies:
- Spraying should be carried out in the evening to avoid burns on the leaves.
- Before each treatment a fresh solution is prepared. Such funds are not subject to storage.
- Spraying is carried out at least two times, until the disappearance of signs of damage.
- Before processing, it is necessary to remove and destroy infected leaflets and buds by burning.
If the folk remedies turned out to be helpless against powdery mildew on roses, it is necessary to move on to more radical control measures — to spray with fungicides: drugs designed to treat fungal diseases.
Today, a large selection of bio-fungicides and systemic fungicides is on sale.
Among the systemic fungicides most commonly used are: “Skor”, “Fundazol”, “Maxim”, “Topaz”, “Baktofit”, “Fundazim”, “Kvadris”.
In search of funds, than to treat roses from powdery mildew, gardeners resort to recommended bio-fungicides, which include:
Recommendations for the treatment of fungicides:
- Processing carried out with an interval of 10-14 days.
- It is better to spray in the evening.
- Preparations need to be alternated, because the fungus that stimulates the disease, can get used to the active substance in the composition of a particular means.
Thus, powdery mildew is one of the serious fungal diseases that many plants are exposed to. Unfortunately, beautiful garden flowers are no exception. However, having the necessary information about the causes of powdery mildew on roses and how to deal with it, you can keep it out of your rose garden, observing preventive measures. If it was not possible to avoid the disease, then use proven folk growers or fungicides tested by gardeners, and she will certainly deviate from your flowers.
What is this disease
Mealy dew is a fungal disease, the causative agent of which is the Sphaerotheca pannosa. This disease affects a wide variety of plants, including roses.
Even in the IV century BC, gardeners fought this devastating contagion. Fungal spores penetrate the garden plot from the environment, and if timely measures for decontamination are not taken, they can strike and destroy a significant part of vegetable and fruit plants, berries and flowers in a short period of time.
The affected parts (stem, leaflets, buds) of plants are covered with a dusty coating of white or gray color, which can be easily erased. Powdered plaque - this is the mycelium of the Sphaerotheca pannosa pest.
Over time (2-3 days) leaves fade, turn yellow. Young shoots grow compressed and ugly. In order to avoid the death of plantations, it is necessary at the first manifestations of fungal lesions to treat plants with pesticides.
The main root cause of the disease in the rose garden is of course the penetration of the fungus into the garden plot. For the time being, spores can be in the ground, be transported by wind, insects from one plant to another, get into shrubs with watering (if water is infected), as well as the gardener himself can provoke infection of flowers if he touches sore bushes, vegetables, trees .
Powdery mildew on a bed of rose bushes may be due to the following reasons:
- thickened, dense planting of flowers,
- poor lighting - the arrangement of the flower garden in the shade,
- overabundance of nitrogen fertilizers in the soil,
- reduced content or lack of calcium in the soil,
- sharp daily changes in air temperature,
- lack of ground ventilation
- long, rainy weather or drought.
All these factors contribute to the creation of a favorable environment for the propagation of fungal spores and infection of the gifts of flora.
Completely get rid of powdery mildew will allow chemicals specifically designed to kill fungal diseases in garden plants. One of the most common and effective fungicides are:
- Fundazol is a toxic chemical, the inhibitory effect of the fungus Sphaerotheca pannosa within three hours after spraying and completely destroys the disease-producing flora within 24 hours. Preparation of the working mixture, the number of treatments and the intervals between them are carried out strictly according to the attached instructions.
- Topaz is a one-component fungicide that stops the reproduction of fungi completely and without residue by suppressing the germination of their spores. Possessing a long period of exposure to the spores of fungi, it reduces the harmful, pesticidal effects on plants.
- Skor - low toxic toxic chemicals, broad-spectrum. Specially designed for indoor and garden flowers. The number of treatments with this drug is not more than four.
Fungicides should be changed and alternated in order to avoid addiction of the fungus to pesticides and the development of sustainable immunity to them.