Roses, of course, are the adornment of any garden, but for them to grow well and delight in their appearance, they need quality care. One of the main problems that a gardener can face is black leaf spot.. This disease is fungal and destroys the plant very quickly. Let's talk about preventive measures and how to treat this disease.
Causes of black spots
To conduct an effective treatment of any disease, it is necessary to know the reason for its occurrence, which should be eliminated as soon as possible.Black spots on rose leaves
There are several reasons why black spots appear on rose leaves.:
- If in quality nisin was chosen for the landing site or strongly thickened terrain, the evaporation of moisture will be very slow, resulting in the fungus will multiply and spread as quickly as possible;
- In warm and humid weather mushroom spores are activated, and the roses begin to blotch out;
- Incorrect feeding (lack or excess) can also cause the development of the disease;
- Also very important carefully care for flowers and in time to stop any provoking factors.
On the development of black spot on the leaves of roses can contribute factors that do not depend on the person, such as wet weather or high rainfall. Also the multiplication of the fungus is influenced by the absence of air circulation and the strong thickening of the shrub.
Also experienced gardeners recommend to know in advance the full information about the purchased variety, including resistance to black spot. If the plant is immune to the disease, the risk of infection will be minimized, otherwise the fungus will be able to comfortably reproduce on the leaves of the rose.
SymptomsWhen black spot rose leaves begin to turn yellow and fall off
Usually, the disease begins to manifest itself in the second half of summerIt is also possible that several outbreaks of spotting occur in one season. The parasitic fungus infects the soft, green part of the rose, namely the leaves and young shoots.
Experts identify the following signs of black spot:
- bush stops growing and develop;
- dark spots on the leaves can reach 15 centimeters in diameter;
- stain shape resembles the sun;
- disease develops from the bottom up;
- gradually a few small spots merge into one;
- affected leaves turn yellow, roll up and fall off;
- bushes dramatically thinThe colors are much smaller.
There are several ways by which you can get rid of the disease, but the original method will be cutting and burning the affected foliage. Many gardeners lovers are greatly mistaken, thinking that if a rose leaves leaves and overwinds in the fall, the disease will disappear. Unfortunately, this is not the case; fungal spores survive well in the soil and again infect the plant.
Immediately after the discovery of the disease, the rose must be treated with fungicides, the active ingredients of which will be zinc and mancozeb. The procedure is repeated every 2 weeks., it is recommended to spray the bush with various preparations in order to avoid the addiction of the fungus. The most effective means are considered:
- Ridomil Gold;
- Copper Oxide
- Ridomil Gold
- Fungicide Scor
- Fungicides for the treatment of rose spot
You can also use Brodsky liquid., with which they treat not only the plant, but also the soil. Similar procedures are repeated until the spotting stops growing.
Biological preparations and folk methods
In addition to chemicals, you can use biologically active drugs that are less harmful to the environment, but in some cases have less effectiveness. That is, they will be useful in the initial stages of the disease, when the growth of spotting can be quickly stopped.
Well-proven drug Fitosporin-m, which is necessary to spray the plant and water the soil every 5-7 days. The number of procedures is not limited, only the minimum number is indicated - 3 treatments.Fitosporin-M - a drug for the prevention and treatment of fungal and bacterial plant diseases
Popular methods are the most accessible, they can be used by the first spotting detection:
- Infusion cooked Onion Husk Based;
- Dandelion infusion, nettle or horsetail;
- Also helps well infused cow dungdiluted with water;
- Many gardeners insist ordinary grass;
- Another way would be application of crushed ash to the plant.
Other diseases of the rose, characterized by leaf spot
In addition to black leaf blotches, a rose can suffer from the following diseases that affect its foliage:
CercosporosisBrown spotting or chalcosporosis
It provokes the infection with the fungus churches. This disease manifests itself in the form of small, round brown spotsappearing on the foliage and young shoots of the bush. An interesting feature is that the shade of the edging of the stain is darker than its middle. At the end of a certain time, white mushroom plaque can be noticed on the contaminated sites.
SfacelomePurple spot or sphaceloma
The causative agent of the disease is the fungus of the same name. On the upper side of the sheet are purple spots, the framing of which is painted black, is also characterized by the presence of dark scarlet stripes. Gradually, the purple color changes to gray, due to the formation of spores. On the lower side, brown solid formations can be seen. The color of the spots on the stem is similar to the spots on the foliage.. The only difference will be that the shape changes from round to oblong. At the same time, the formations become convex.
PerinosporosisRose leaves are affected by peronosporosis
The second name of the disease is downy powdery mildew. Initially purple or dark red spots of arbitrary shape are formed on the leaves., a closer look at them can be seen a thin cobweb. Then the leaves curl up and die. The stems are cracked, the buds also lose their vitality.
Having considered several diseases, it can be concluded that Rose spotting is caused by a fungal pathogen., a favorable condition for which will be moisture, heat, shade, stagnation of air, etc.
As a preventive measure, you need to properly care for shrubs and perform the following actions.:
- First of all it is necessary keep the flower garden clean and in time to remove weeds;
- Spring and autumn is held sanitary pruning, during which all dry and damaged branches are removed, it is also necessary to defuse the crown of the shrub so that the air can safely move;
- Plants must be planted this way.so that when a single shrub is infected it is possible to avoid the spread of the disease throughout the garden;
- The acidic environment is favorable for the fungus, therefore soil needs to be lime or add dolomite flour;
- Roses needed timely introduction of phosphate, potash and complex mineral fertilizers, and nitrogenous fertilizers obtained in large quantities can harm the plant. Therefore, it is very important to comply with all the proportions while making dressings;
- It is recommended to break through the soil before wintering.so that the fungal spores go up and come under the influence of cold temperatures, and as a result they die;
- During the preparation of shrubs for winter is necessary collect and burn diseased foliage, cover the roses only in the absence of leaves.
- When preparing roses for winter and immediately after the snow melts the soil is treated with copper or iron sulfate, while drugs are recommended to alternate;
- Well proven growth stimulant treatments and drugs to improve the immunity of the rose;
- When the first foliage the plant is sprayed with chemical (1 procedure) or biological (2 procedures with an interval of 5-7 days) preparationsabove.
Another preventive method will be the correct neighborhood, that is next to the roses you can plant lavender, calendula or sage. Every gardener must remember that disease is easier to prevent than to cure.
The leaf spot of the rose is caused by the presence of the fungus, the danger of the disease is that it spreads very quickly and it is rather difficult to protect healthy plants from it. In order to avoid the appearance of spotting, it is necessary to ensure the proper care of the shrubbery.. But if the infection still happened, the treatment will take a sufficiently long amount of time.