If a white powdery coating appears on flower petals or leaves, then a pathogenic fungus is present. Pathogenic microflora with the same frequency affects various plants, and powdery mildew on roses appears no less than on watermelons. Getting rid of trouble is not as difficult as many gardeners think. The main thing is to know the basic rules of the fight against infection.
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Signs of powdery mildew
As the doctors say: "The correct diagnosis is 50% of successful treatment." So the gardener must correctly identify the disease in order to choose the appropriate methods of dealing with it.
In the case of powdery mildew, “diagnosing” will not be difficult, since it has a number of characteristic signs:
- powdery white or light gray plaque covers the upper part of the leaf plate, stem, buds and petals of blossoming flowers;
- upon closer inspection, the spots look like the thinnest layer of a web or cotton;
- yellowness and necrotic spots appear on the leaves;
- rose bushes slow growth, buds become smaller, some do not open at all.
When looking at roses affected by powdery mildew, it seems as if the flowers are sprinkled with flour or sprinkled with a solution of lime. If such associations arose, then 100% of the flower garden was captured by a malicious fungus.
The pathogenic organism feels best at an air temperature of + 15 ... + 25 ° C and a humidity of 60-75%. Therefore, the rapid spread of infection occurs from early July to early September.
Fungicides to effectively combat plant disease
If a pathogenic fungus has already taken over the garden, then the logical question arises: "How to get rid of powdery mildew on roses?" Traditionally, gardeners use such highly effective fungicides (for reference: the word "fungicide" is translated from Latin as "killing mushrooms"):
| Drug name | Active substance | Breeding rate | Application rate | The best period for processing |
|---|---|---|---|---|
| Agrolekar, Chistoflor, Forecast | Propiconazole | 10 ml of the drug per 10 ml of water | 0.5 L per rose bush | The growing season before flowering and a week after flowering |
| "Rake" Purebloom, "Speed" | Diphenoconazole | 2 ml of the drug per 10 ml of water | 10 liters per 100 square meters | At the first sign of illness. Repeat after 2 weeks |
| "Topaz" | Penconazole | 2 ml per 5 l of water | 1.5 liters per 10 square meters | At the first sign of illness. Repeat after 2 weeks |
| "Vectra" | Bromukonazole | 2 ml of the drug per 10 ml of water | 1000 l per 1 ha | Once upon first manifestations of infection |
| Fundazole | Benzimidazole | 10 g diluted in 10 l of water | 1.5 liters of solution is consumed per 10 sq.m | At the first sign of illness. Repeat after 2 weeks |
| Quadrice, Folicuo, Defender | Azoxystrobin | 2 ml of the drug per 10 ml of water | 0.5 L per rose bush | At the first sign of illness. Repeat after 2 weeks |
| Colloidal sulfur (roses are very responsive to this substance) | Sulfur colloidum | 30 g per 10 l of water | 3 liters per 50 square meters | At the first sign of illness. Repeat after 2 weeks |
All the fungicides listed above can be used both on large production sites and in private households on small flower gardens. It is recommended to spray rose bushes in dry, calm weather in the morning and evening. When working with the drug, you must adhere to the safety rules.
Important! It is not recommended to use the same fungicide more than three times in order to avoid the addiction of the fungus.
The best folk methods against powdery mildew
Some gardeners flatly refuse to treat plants with chemicals, citing their toxicity. In this case, how to treat roses from powdery mildew?
It is interesting: powdery mildew on currants - control measures
For fans of environmentally friendly materials, there is a whole list of folk remedies for combating fungi:
- serum - one of the simplest and most affordable, but at the same time effective means. To prepare the solution, it is necessary to dilute the serum with water in a ratio of 1: 2, at 10-11 in the morning on a sunny day generously spray rose bushes with the solution. Repeat the procedure after 10 days;
- wood ash - 1 kg of ash should be poured into 10 liters of water, add 2-3 tablespoons of grated soap, infuse for 4-5 days, stirring occasionally. Strain the solution through a double layer of thick gauze and spray roses to prevent powdery mildew;
- iodine - Dilute 10 ml in 10 l of water, spray diseased plants abundantly;
- soda solution - Pour 50 grams of soda ash and 200 grams of laundry soap with two liters of hot water, pour a solution of copper sulfate in a thin stream (10 g per glass of water), mix everything. Add water up to 10 liters and generously spray the rose bushes with the resulting product;
- potassium permanganate - 2-3 grams of "potassium permanganate" mix in 10 liters of water, spray flowers every 5-8 days until flowering;
- mustard powder - Dissolve 2 tablespoons with a slide in 10 liters of very warm water. After cooling, spray flowers abundantly.
Assistive Methods
Simple agricultural methods can protect plantings from powdery mildew, do not allow fungi to spread rapidly when they enter the site.
These include:
- weed weeding,
- loosening the soil to improve its aeration,
- planting rose bushes according to the optimal scheme. Miniature roses are planted half a meter apart, medium-sized plants at a distance of 60-70 cm, park and curly - 80-100 cm, semi-climbing - 120 cm. Plants are less likely to be placed less often because of the risk of the earth drying out in hot weather;
- immediate removal of damaged areas of plants and burning them outside the rosary;
- disinfection of garden tools after working with diseased flowers;
- the introduction of nitrogenous fertilizers strictly within normal limits, since their oversupply creates a favorable environment for the development of powdery mildew;
- top dressing of roses at the beginning and end of May with liquid vermicompost to increase their resistance to diseases. A nutrient solution is prepared at the rate of 1 cup of liquid vermicompost per 10 liters of water, when irrigating use 0.5 liters of finished top dressing per 1 bush.
Disease-resistant rose varieties
In order not to think about how to get rid of powdery mildew, you can plant on the plot varieties that are resistant to the disease: Cadillac, Westminster, Crocus Rose, Rosaman Jeanon, Gloria Day, Hot Chocolate, Halle, Aphrodite, Dark Desire.
All these varieties are resistant not only to powdery mildew, but also to other diseases, as well as to frost and pests. Therefore, a gardener can grow a wonderful garden without any problems, having bought the necessary seedlings and having completed all agricultural operations.
