dew on roses
Fungal infections affect many garden plants, among them not only vegetables, but also flowers. Powdery mildew on roses is common, it is very easy to determine that the plant is infected — a thin white coating appears on the leaves and buds, resembling spilled powder. The infection quickly spreads to neighboring plants, if treatment measures are not taken, expensive varieties can be lost, and in a short time. How to treat roses from powdery mildew — the answer is in this article.
Causes of Powdery Mildew
Fungal plaque on roses has a white or cream color. The rashes are easy to wipe off by hand, but after a short time, new extensive foci will appear on the leaves or buds, sometimes they merge into one large spot.
Where does the fungal infection in the rose garden come from? This question is asked by beginners and experienced flower growers, and there are several reasons for infection with powdery mildew:
- Poor lighting of the rose garden — the queen of flowers loves to bask in the sun, plants stretch in partial shade, few buds are formed, and when roses are planted in the shade, growth inhibition is observed, which leads to a decrease in immunity.
- Thick plantings — when planting rose bushes in the garden, the distance between plants should be observed. Depending on the group, the bushes are planted at different intervals: for miniature roses, it is enough to leave a gap of 35-50 cm; floribunda and hybrid tea roses are planted after 60 cm; for climbers, the distance between the bushes is left at least 1 m.
- Too dense soil — when planting rose bushes, it is very important to properly compose the substrate by adding sand, peat, humus and leafy soil to it. During the season it is useful to carry out several loosening of flower beds with roses.
- Sharp temperature changes — with a difference in day and night temperatures, condensate (dew) forms on the plants, which can lead roses to powdery mildew.
- An excess of nitrogen in the soil — a balanced top dressing maintains the necessary balance of microelements in the soil, so do not get too carried away by introducing humus and manure under roses, especially during the budding period.
- Calcium starvation — in the summer you can spend 1-2 foliar top dressing of roses with a cocktail of trace elements, including calcium.
- High humidity — in rainy weather, the risk of infection with powdery mildew increases many times over.
Is any plaque — powdery mildew
On garden roses, there are two fungal diseases that affect the plant:
- Powdery mildew — mushrooms develop rapidly on the top of the leaves. At first, the plaque is white, with time it becomes gray-white. Gradually, the fungus populates the lower part of the leaf blade. The leaves wither and fall off. When buds become infected, they fade over time if timely treatment is not started.
- Downy mildew (peronosporosis) — infection with fungi occurs from the bottom of the leaves. The leaves of roses first discolor, then red-brown, as if burned, foci appear on them. Pathogenic fungi remain in the form of mycelium in the tissues of roses, after decay of infected plant residues, the soil contains pathogens for 7 years. The optimal temperature for the development of infection is 15–18°C.
Both diseases are caused by pathogenic fungi, while the greatest damage is noticeable on weakened plants, during the cultivation of which, the rules of agricultural technology were not followed.
Important! In roses that have recovered from powdery mildew, immunity and protective properties are sharply reduced, it is difficult for such plants to endure wintering. Powdery mildew on roses: control measures
If signs of infection of garden roses with powdery mildew are found, urgent treatment measures must be taken. Popular methods of treating powdery mildew can be divided into two groups.
Folk remedies for powdery mildew on roses
Folk remedies will not help plants on which the disease progresses greatly, you can not do without the help of fungicides. Periodic inspections of rose bushes for infection with fungal infections will help to quickly identify the disease, and begin treatment earlier.
For the treatment of diseased roses, solutions can be prepared according to the following recipes:
- Whey treatment — 1000 ml of whey is diluted in a bucket of water at room temperature. The solution is well mixed and treated with rose bushes. Multiplicity of processing — 1 time per day for 3 days in a row.
- Serum + iodine — the solution is prepared from the calculation: for 10 liters of water, take a liter of serum and 10 drops of ordinary pharmacy iodine. Multiplicity of processing: 2 times with a break of 7 days.
- Soap-soda solution — soda ash (25 g) and liquid soap (5 g) are added to hot water (5 l). Plants are treated with a cooled solution 2 times with a break between procedures — 1 week. It is useful to process the top layer of soil under rose bushes with this solution.
- Medicine from baking soda — dissolve 1 tbsp in 4 liters of water. l. baking soda and half a spoonful of liquid soap. Mix everything intensively, you need to process the roses 3 times with an interval between procedures — 1 week.
- Also, to treat the powdery mildew rose garden, you can use an infusion of garlic or mustard. Perfectly copes with the infection infusion of fresh manure.
- Ash infusion is a very effective remedy for fighting fungal diseases, but there is one drawback — long cooking. But this tool is absolutely harmless to plants and humans. 1 kg of wood ash is added to 10 liters of hot water. Insist the medicine for 7 days. After that, diseased roses can be treated with a solution.
Powdery mildew on roses: treatment with fungicides
For the treatment of advanced cases of infection of roses with fungal infections, it is recommended to use special agents — fungicides.
The most popular means among summer residents: Oxyhom SP; Ridomil Gold MC; Topaz; Order of the joint venture; Previcur Energy; Consento COP; Alirin-B; Fundazol; Maksim.
Chemical preparations are used to treat the rosary strictly in accordance with the manufacturer’s instructions. It is not recommended to spray roses in windy or rainy weather. Be sure to take precautions when working with chemicals.
Treatment of diseased roses with folk or chemical remedies will help get rid of a pathogenic infection, but in order to prevent such a situation from occurring again, the agricultural practices of growing roses should be carefully observed.