Mealy dew is one of the most common and unpleasant diseases that a large number of plants suffer from. It is imperative to fight it, because the outcome of the neglected disease is the death of the plant. Especially unpleasant when the disease destroys the beauty of ornamental plants.
In this article we want to share recommendations on how to prevent powdery mildew on roses and what to do if it does hit the flowers.
Did you know? For the first time the disease, such as powdery mildew, was recorded in Europe in 1907. It was imported from America.
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 they live on a mushroom 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; his buds are deformed, not disclosed; leaves turn brown, turn black and dry up. 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.
Important! Two types of roses are most susceptible to powdery mildew: hybrid tea and remontant.
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.
Mineral fertilizers, despite their ease of use, are not very desirable in many farms, so people are often interested in how to fertilize plants with homemade compost, sheep, pork, cow, horse, rabbit dung, chicken manure, charcoal, nettle, yeast.
Preventive measures
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, preference to give organic supplements;
- prophylactic spraying with special protective preparations;
- thorough autumnal processing of the rose garden with cleaning of dry foliage and deep digging of tree trunks;
- Choice for planting disease resistant varieties.
Did you know? Modern breeders brought a number of new varieties of roses that are most resistant to powdery mildew. Among them are garden groups of scrubs, floribund, ground cover and climbing.
According to experienced gardeners, the five most resistant varieties include:- "Leonardo da Vinci".
- "Wedding Bells".
- New Dawn.
- "William Shakespeare 2000".
- "Rosters Yuterson".
0.25% Benomil, 0.4% Zineb, 0.1% Fundazol are also used. 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%).
Folk remedies
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.
Important! Despite the fact that folk remedies do not usually use substances hazardous to human health, however, eyes, nose and mouth during treatments should be protected so that solutions do not get on the mucous membrane and do not cause allergic reactions.
Chemical attack
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 often 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:
- "Fitosporin-M".
- "Alirin-M".
- "Hamair".
- "Planriz".
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.
Important! When spraying chemicals should observe personal safety measures. Processing is carried out on a dry windless day. Protect the body with a special suit, eyes with glasses, nose and mouth with a mask.
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.
