Like all cultivated plants, roses suffer from diseases and pests. However, this should not be taken as something inevitable. As a rule, pests are especially dangerous for roses growing in conditions unfavorable for culture. Sometimes certain weather conditions play a decisive role, and more often a complex of these factors.
The most common pests are: rose aphids, thrips, spider mites, rose leafhoppers; roses also hurt different kinds sawflies, nutcrackers, beetles, weevils, bronzes, etc.
High temperatures, for example, can promote the multiplication of some pests, and prolonged wet weather causes the spread of fungal diseases.
If, moreover, roses grow in an unsuitable place for them, then diseases are inevitable:
- Gray rot, for example, spreads especially quickly in wet weather, in addition, many gardeners plant roses densely, the soil under the plants does not dry out quickly enough after rain.
- Foliage that does not dry out for a long time or cool nights, dew in the morning favor black spotting.
- Powdery mildew, and from pests - spider mite, on the contrary, love dry and hot weather. Therefore, roses growing near southern walls or fences are especially affected by these pests.
Pests and diseases of roses with photos, descriptions and methods of treatment - for your attention on this page.
Fungal disease of roses powdery mildew and how to get rid of it
To get started, check out the photo and description of powdery mildew rose disease, which develops due to a lack of calcium or drying out of the soil.
Powdery mildew... Appears on young leaves, shoots and buds powdery bloom; their thickening and curvature is observed.
Powdery mildew on roses represents mycelium and sporulation of the fungus. The causative agent of the disease in the form of mycelium in the kidneys hibernates. The development of the disease is facilitated by excessive nitrogen fertilization, lack of calcium in the soil, drying out of the soil, too light sandy or, conversely, cold damp soils.
Look at the photos of powdery mildew on roses, presented below:
Indoors, this rose disease develops especially strongly in rooms with insufficient lighting, humid, stale air. Sudden changes in temperature, drafts, drying out of the soil in pots and other conditions that disrupt the normal life of plants reduce their resistance to disease. Tea and varieties with more delicate foliage are especially strongly affected by this fungal disease of roses.
How to get rid of powdery mildew on roses and prevent re-infection?
When the first signs of the disease appear, it is necessary to spray the bushes: "Topaz", "Fundazol" or "Skorom". You can use the systemic drug "Raek" with long-term prophylactic and therapeutic effects.
Rust on roses: a description of the disease and how to treat it
Rust... The affected parts of the shoots are bent and thickened.
As you can see in the photo, with this disease of roses in spring, orange dust appears on the stems at the opening buds and at the root collar:
These are spring sporulation of the fungus - the causative agent of the stem form of rust. The fungus overwinters in plant tissues infected in previous years. Rust develops most intensively on roses in years with warm and humid spring.
Rust fungi not only take away nutrients in a plant, but also strongly disrupt its physiological functions: they increase transpiration, reduce photosynthesis, make breathing difficult and impair metabolism.
In summer, small, red-yellow pads of summer spores form on the underside of the leaves, which can give several generations and infect new plants.
In the second half of summer, winter sporulation begins to appear on the underside of the leaves in the form of small rounded black pads. If the disease is severely affected, the leaves completely turn yellow and fall off prematurely.
The spread of spores of a rust fungus occurs with the flow of air, water, and planting material.
How to treat rust on roses and when is the best time to treat plants?
To combat rust, one-sided nitrogen fertilization should be avoided. In autumn, it is necessary to remove and burn the affected foliage, and in early spring(before bud break) spray the plants and the soil around them iron vitriol(1 - 1.5%). The soil under the bushes should be loosened and mulched to reduce infection.
Recommended carefully and in a timely manner, affected by the stem form of rust. To treat this disease of roses, from the moment the buds bloom, re-spray the plants (1%) or its substitutes (Oxyhom, Abiga-Peak, Khom, copper oxychloride, Ordan, Topaz).
How to deal with black spot rose leaf disease
Black leaf spot (marsonina). In the second half of summer, dark brown, almost black, spots form on the leaves different sizes... Leaves turn brown and often fall off prematurely. Spots can also appear on green bark. annual shoots.
Plants with prematurely fallen leaves sometimes start to grow again, as a result of which they greatly weaken and bloom poorly the next year.
Under the skin of the leaves, the mycelium of the fungus, the causative agent of the disease, develops, forming radiantly growing strands. This radiance in case of black spot disease of rose leaves is clearly visible at the edge of the spots. Foliage that does not dry out for a long time or cool nights, dew in the morning favor black spotting.
Roses are more sick with a thickened planting, in shaded places, with poor ventilation of the site.
How to deal with black spot on rose leaves and when to start processing plants?
Measures to combat this disease include: proper agricultural practices that increase plant resistance; careful removal of affected leaves in the fall and burning them; spraying plants during the growing season with preparations containing copper, which are used to combat rust. Treatments must be started at the first signs of the disease and repeated after each rain or abundant growth.
Gray rot on roses: description and how to deal
The following describes the disease of roses, rot, and how to deal with it on a personal plot.
Gray rot, for example, in wet weather it multiplies especially quickly, and given that many gardeners plant roses densely, the soil under the plants does not dry out quickly enough after rain or watering. This fungal disease affects primarily buds and pedicels. A whitish-gray fluffy bloom appears on them. The buds do not open, they rot.
Fogs and morning dews, as well as excessive sprinkling irrigation, especially in the evening, contribute to the development of rose gray rot. With excessive moisture, the entire bush can get sick and die.
Avoid planting roses next to gray rot strawberries more often than other plants.
How to deal with gray mold on roses using effective remedies?
At the first sign of the disease, spray the affected plants with a solution of Euparen Multi. Also water the soil under the bushes with a solution of the drug "Fitosporin-M", "Alirin-B" or Gamair.
Bacterial cancer on roses: photos and how to deal with the disease
Bacterial cancer... On the root collar and roots of plants, growths of various sizes are formed. Sometimes they are barely noticeable, but often they reach several centimeters in diameter.
See what bacterial cancer looks like on roses - growths consist of soft tissue, have an uneven tuberous surface:
In the process of decomposition by bacteria, they gradually change color from white to brown. There are also hard lignified growths that grow every year.
Less commonly, the aboveground part is affected - trunks and branches, mainly in standard repair roses. Here, lumpy nodules and tumors of various sizes are formed.
The causative agent that causes bacterial cancer in roses affects many plants belonging to different families. Infection occurs through wounds on the roots of plants, from the soil, where bacteria can persist for a very long time.
The development of the disease is facilitated by high humidity soil, abundant manure fertilization, root injuries, alkaline soil reaction.
When transplanting a plant with an affected root collar, it is necessary to destroy, and cut off the growths on the lateral roots. After pruning, the roots are immersed for 5 minutes in a 1% solution of copper sulfate, and then washed in water and dipped in liquid mixture clay with sand. With stem cancer, depressed necrotic spots first appear, on which the bark cracks, then their edges thicken. Affected stems die off if the edges of the spots close together.
Burns of leaves and branches of a rose: description and fight against the disease
Burning leaves and branches of roses - fungal disease. On the branches, first reddish spots appear, later - darkening spots in the middle; the reddish-brown edging persists for a rather long time. Growing up, the spots ring the branches. Above the affected area, tissue build-up may form. Diseased branches usually dry out in the second half of summer.
Excess moisture under the winter shelter contributes to the development of the "burn".
To avoid severe damage to roses, you should remove the shelter earlier in the spring. Sick and frozen branches must be cut off and burned in a timely manner, and the plants must be sprayed with preparations containing copper, as in the fight against rust.
Correct agricultural technology (timely fertilization, loosening and watering) helps to reduce the harmfulness of the disease, it is necessary to achieve good maturation of the wood until the end of the growing season.
For the winter, plants should be covered, if possible, in dry weather so that high humidity is not created under the shelter.
Before the shelter, unripe shoots and leaves are removed, and the plants are sprayed with a 3% Bordeaux mixture or 1.5% ferrous sulfate solution.
Cytosporosis: photo and treatment of roses from disease
Cytosporosis- This fungal disease is ubiquitous. Roses, as well as pome and stone fruit trees, and a number of ornamental shrubs are striking.
Cytosporosis is also called infectious desiccation. In some years, it leads not only to the drying out of individual branches, but also to the death of plants. This disease is especially susceptible to bushes weakened as a result of freezing, drought, sunburn, untimely trimming, etc.
First, the causative agent of the disease settles in the dying off individual parts of the cortex. Over the entire area of the affected bark, large, well-visible orange-red tubercles appear - pycnidia of the fungus, protruding from under the skin.
Cracks form at the border of the affected and healthy tissue. The causative agent of the disease moves first upward through the tissues and blood vessels of plants, and after the branches dry up - downward, killing the cells adjacent to the zone of its distribution with its toxins.
The disease with cytosporosis should be considered as a secondary phenomenon associated with a general weakening of plants, therefore, when choosing control measures, it is first of all necessary to protect the bushes from mechanical and other damage. And also regularly carry out activities that increase the viability of plants - timely and correct pruning, fertilizing, soil cultivation, watering, protection from sunburn, increasing winter hardiness, cutting and burning branches that have signs of disease with the capture of up to 5 cm of a healthy part of the branch.
How to treat roses from this disease in order to contain the spread of infection?
Early spring pruning of plants, spraying roses with 0.5% "Abiga-Peak" or 3% Bordeaux liquid on a green cone to some extent restrain the spread and development of the disease.
Pest of flowers and rosebuds green aphids
Green aphid damages roses and rose hips, damages greenhouses and open ground... The pest among other species of aphids is rather large, shiny, green in color, sometimes brown with very long black antennae.
In the spring, the larvae of these pest of rosebuds appear from the overwintered eggs, turning into wingless females. Among subsequent generations, winged settler females appear, migrating to other plants, where they form new colonies. Ten generations or more develop during the year.
The number of these pests of roses in the open field usually increases in June, and they harm until the end of summer. Aphids settle mainly at the ends of young shoots and buds, there are few aphids on the leaves. Rose shoots damaged by green aphids are often bent, and the buds do not open.
The treatment of roses from these pests begins when the first larvae appear and is repeated as needed after two to three weeks until the aphids completely disappear. For this purpose, use: "Spark Double Effect", "Iskra-M" or "Confidor", "Commander", "Tanrek", "Zubr".
A significant advantage of the listed drugs for pests of rose flowers is their high efficiency even in hot weather, systemic mechanism of action, rapid penetration into plant tissues and is not washed off by rain.
In nature, aphids are destroyed by a lacewing and a ladybug.
Spider mite on roses: photo and how to get rid of it
Spider mite on a rose is especially dangerous for roses in dry, hot summers. Optimal conditions for its development the temperature is + 29 ... + 31 ° with air humidity below 35%. Under such conditions, the number of ticks rapidly increases, because every 10-15 days a new generation of the pest appears.
As you can see in the photo, the spider mite on the rose sucks the cell juice from the leaves, as a result of which small light spots (pricks) appear on them, the leaves turn yellow, dry up and fall off:
How to get rid of spider mites on a rose using spraying?
Most effective in combating spider mite are: Fufanon and Iskra-M. Spraying roses in the presence of a tick must be repeated after 10-12 days until its harmfulness decreases. If in the fight against powdery mildew if you use Tiovit Jet or colloidal sulfur, these drugs inhibit the reproduction of ticks.
Rose leafhopper: description and treatment of roses from the pest
Below you will find a description of the leafhopper pest of roses and learn about the fight against it at their summer cottage.
Rose cicadus... The larvae of the rose leafhopper settle on the underside of the leaves, suck out the juice. The upper surface of the leaves changes color, they turn white, acquiring a marble color. With a large number of pests, damaged leaves fall prematurely. Roses growing in warm, sheltered places especially suffer from leafhoppers.
The pest itself is a small white-yellow insect with two pairs of wings, which in a calm state fold over the back like a roof. The length of an adult insect is 3.5 mm, width is 0.7 mm.
Look at the photo - this rose pest resembles an apple leaf:
The larva is white or pale yellow with a wedge-shaped pointed abdomen. The length of the larva is 2 - 3 mm, the width is 0.8 mm.
Eggs overwinter on branches at the base of the buds and in forks. Larvae appear during bud break. They develop during May-June. Unlike the larvae of aphids and leaf beetles, they are very mobile: disturbed, they quickly escape to the opposite side of the leaf.
At the end of June, the wing buds appear in the larvae, and they turn into nymphs. In early July, leafhoppers fledging, adult insects appear. Winged leafhoppers, like larvae and nymphs, settle on the underside of the leaf, sucking the juice out of them. After fledging, the adult leafhopper leaves the leaf on which it fed and flies off to the grass and other plants or branches.
On leaves damaged by leafhoppers - whitish with a marble color - white skins remain on the underside after molting of larvae and nymphs.
In addition to roses, leafhoppers damage rose hips and other plants from the Rosaceae family.
How to treat roses from these pests in order to protect the plants?
In the fight against the pest, use the same drugs as for the fight against aphids. When spraying roses from pests, make sure that the underside of the leaf is carefully covered with a solution of poison.
Rose sawfly and leaf cutter bee on roses
Here you can see the photo description of the pests of roses, rose sawfly and leaf cutter bee.
Sawflies(rosaceous, slimy, comb-shaped, descending) gnaw at the leaves from the edges or scrape off the upper skin of the leaf, eat out holes in the leaves. A descending sawfly, appearing at the top of a young shoot, penetrates into the shoot, grinds a passage up to 4 cm long there, as a result the shoot hangs, the leaves wither on it. Sawflies hibernate in the soil in cocoons.
To combat these pests, the same preparations are used as against aphids, and spraying with the "Lightning" preparation also gives a high effect.
Leaf cutter bee... On the leaves of roses and rose hips at the end of June - July, you can see correctly cut oval or perfectly round holes.
This is the job of a leaf cutter bee that uses them to build its nest. Having chosen a suitable ready-made cavity - an abandoned bee's burrow, a barbel or an earthworm's burrow - the bee begins to clog it with casually cut pieces of rough leaves of oak, grapes, hawthorn. This plug serves to protect the socket.
After the cork is made, the bee begins to carve oval pieces of the more delicate rose leaves. Sitting on a sheet, she, like scissors, carefully "cuts" it, starting from the edge and gradually turning in a circle. First, the outer layer of the cell is made from large leaves, covering about a third of the circumference of the channel, so that the individual pieces overlap, and their lower ends turn out to be bent, forming the bottom of the cell. After that, the builder closes the gaps left between the first pieces with smaller pieces of leaves and thickens the walls.
In order to seal the food-filled cell, the bee cuts out perfectly round pieces of leaves. In this case, the diameter of the first of them is exactly equal to the diameter of the cell, and the subsequent ones are cut out large and turn out to be concave inward, forming the bottom of the next cell. The first cell is followed by the second, and so on.
The largest nest of the leaf cutter bee has up to 17 cells. In total, it takes over 1000 pieces of leaves to build the nest, including the cork.
The ready-made nest of the bee - leaf cutter is a long cylinder that easily disintegrates into individual cells. The leaves that each one is made of are easy to make out. Later, it is more difficult to do this, since, while pupating, the larva releases a sticky liquid between the pieces of leaves, which, when solidified, holds them together.
You can protect roses from this bee by spraying the plants in the late evenings with one of the preparations that destroy wasps ("Super fas", "Otos"),
A new remedy has appeared - the “Adamant” wasp bait. Wasps are also scared away by the drug "Sovka-Zh". In the ground, nests can be poured with boiling water.
Beetles on roses: weevils and bronzes
The most dangerous beetles on roses are the weevil and bronze.
Weevils (leaf beetle). These are pests that gnaw the edges of the leaves of all types of roses - beetles of rather large sizes (up to 1 cm). They are black and gray, flightless. Active image lives are led at night, and during the day they hide under lumps of soil. That's why we don't see them. But not only weevil beetles are dangerous for roses, but also their legless larvae, the same large, colors Ivory... The larvae live exclusively in the ground and eat up the roots.
With a large number of pests, rose bushes may die. Due to severe damage to the leaves, their effective area, and the plants wither, and then there are weakened roots.
Weevils are especially dangerous for bushes growing in the shade of trees, in dense plantings, with poor ventilation, as well as for old bushes, weakened by time and poor agricultural technology.
Beetles can be dealt with by spraying roses with one of the insecticides in the evening at sunset. Beetles can be collected manually at nightfall by the light of a flashlight, of course, if there are not very many of them yet.
Golden bronze... This shiny green beetle with a coppery golden hue is very fond of yellow and white roses. The beetle is rather large (10-15 mm long and 12-14 mm wide). On the underside - a bronze-green color with a metallic sheen. On the elytra there are transverse thin, irregular shape, white stripes.
Beetles damage flowers by eating stamens and pistils and gnawing at petals.
Gardeners call it "May beetle". The larva lives in the ground, it is six-legged, thick, white, up to 60 mm long, very similar to the larva of the May beetle, but, unlike the latter, it feeds on humus, does not damage the root.
At the end of summer, the larvae pupate, beetles emerge from them, which winter in the soil, and fly out the next summer.
Beetles fly from May to August, damaging the flowers of not only roses, but also white lilies, fruit plants.
Since plants cannot be sprayed with pesticides during the flowering period, the main measure of combating bronze is manual collection of beetles early in the morning, when they do not fly, but sit motionless on the flowers.
Walnut and scoop on roses: photo and spraying from pests
Walnut... These galls form pests. They are able to destroy the entire rosehip crop, drain the bush. With severe damage, the growth decreases, the winter hardiness of plants decreases. Walnut grubs overwinter in the form of larvae in damaged fruits. Years of adult insects and infestation of young ovaries occurs in late May - early June.
In the fight against nutcracking, it is necessary, immediately after flowering, to spray the rosehip twice with the same pesticides as against aphids and other pests. Good results are obtained by using the preparation "Lightning" (2 ml per 10 liters of water).
In parallel, a mechanical struggle should be carried out (cut off and burn the appearing galls).
Scoops... The moth caterpillars live in the soil and feed mainly at night, so we often see only traces of their activity.
If there is a lot of damage, use pest drugs (the same as against aphids), spray in the evening after sunset.
Depending on the degree of damage, the bud can produce a deformed flower, so it is best not to leave it on the plant.
Thrips on roses: photo and fight with them
Thrips... Small (up to 1 mm) sucking pest. On the buds, flowers, leaves and young shoots of roses, larvae, nymphs and adults of this pest feed.
As you can see in the photo, thrips on roses are light yellow in color:
Thrips weaken roses by sucking juices from leaves, buds and flowers. Buds damaged by pests, flowers, especially of light color tones, are covered with characteristic small red specks. The flower becomes disheveled and fades quickly. At the base of the petals, pests are clearly visible to the naked eye. Small yellow spots appear on the leaves. They take on a silvery hue, as if damaged by a spider mite.
Adult insects hibernate in the upper soil layer and under plant debris.
The most endangered are roses growing in warm, dry places, for example, near the walls of a house, on terraces on the south side, or near paths and areas lined with tiles or covered with asphalt.
In the spring, thrips feed on weeds, then persians fly to rose bushes.
In greenhouses, the pest gives up to eight generations a year. One generation develops within 22 to 30 days.
To combat thrips on roses in case of severe damage, the same preparations are used for spraying roses as in the fight against aphids.
If there are black spots on the leaves of a rose, what should I do? The process of growing roses is impossible without obstacles. The most common plant disease is spotting. The disease is very dangerous for the flower, as it leads to its death. When spotting appears on roses, you should immediately start to fight it. How to avoid spotting on roses? Black spots on roses not only spoil the aesthetic appearance flower, but also bring a lot of harm to the plant. Gradually, the disease spreads throughout the bush and is capable of affecting the nearest ones. The disease is insidious and difficult to cure. The best remedy- this is the prevention of black spot on roses. How to prevent the appearance of the disease: regularly carry out correct pruning plant stems, since "cutting" increases the resistance of roses; remove damaged leaves, buds, flower stems and be sure to burn them in an area far from the bush; constant weeding of the root area; during the rainy season, sprinkling the soil around the bush with ash; processing the plant special means protection for roses; spraying bushes with infusion of mullein or horsetail; correct selection of a site for planting roses: do not plant in darkened and thickened areas; frequent treatment of tools with disinfectants. It is also important to know that there are varieties of roses that are more resistant to black spot. Some, on the contrary, are genetically predisposed to it. Therefore, acquiring planting material this must be taken into account. How and how to treat stains on rose leaves? Currently in specialized stores huge selection drugs that can cure spotting. The main thing is to buy not one product, but several. Special drugs should contain: triazole; mancozeb. They will need to be used alternately for the effectiveness of the action. For the first seven days, rose bushes are sprayed with preparations that include mancozeb. For example: "Gold" or "Profit". A week later, they begin to use products containing triazole, such as Topaz or Skor. It is necessary to process the bushes in the evening so that there is no presence of dew. Before disinfection, it is worth watering the plant under root system... After the spots on the leaves of the rose disappear, you need to carefully examine the flower. With repeated symptoms of the disease, it is worth removing the damaged areas of the plant and burning them. Often, the disease attacks the flower if it is weakened or does not receive the required dose of nutrients. Therefore, it is important to fertilize roses. How to determine black spot: firstly, the plant stops growing; secondly, dark spots(like pads); thirdly, yellowness is visible around the leaves. experienced gardeners use environmentally friendly methods of disease control. The area where the roses are grown is surrounded by plantings of garlic. This vegetable has the ability to prevent fungal diseases(Black spot refers to the genus Marssonina rosae). Also, for prevention, you can spray the bushes with decoctions of garlic or tobacco. Infusions are not addictive to the pathogen and do not harm the plant. Proper maintenance It is very important to regularly prune roses. This process will strengthen the plant's immune system against fungal diseases, which include black spot. Also, if black spots have already appeared on the leaves of the rose, then it is worth cutting off the shoots at the level of 2-3 buds from the base. Then spray the bushes chemical means("Copper oxychloride", "Vectra", "Cumulus"). It is better to remove all weak, old and dry branches, because they will become the target of black spotting. In autumn and spring, it is necessary to process the stems copper sulfate and Bordeaux liquid. All damaged leaves dry quickly, then fall off. They must be collected and burned. Otherwise, the fungus will overwinter, and in spring it will spread to healthy rose bushes. During the growing season, the plant needs free access fresh air do not plant other crops too close. Do not allow long-term presence of moisture on the leaves of roses. To do this, you need to cut off the shoots and weed the weeds. It is better to dig up the adjacent territory regularly, add a fungicide (disinfectant) to the soil. The spread of the disease is facilitated by temperature drops and high humidity. But not only environmental conditions can lead to the defeat of the rose with black spot, but also improper agricultural technology. Therefore, before you start growing these flowers, you need to ask how to properly care for them.
During the second growing season, the leaves are damaged, sometimes annual shoots. The appearance of black spots is associated with meteorological conditions and varietal characteristics.
How to recognize a disease
Symptoms of marsonnina, or black spot:
Purple, purple or white spots appear on top of the leaves of plants;
- over time, black spots appear, ranging in size from 50 to 150 mm.
The shape, size and location of the spots also depend on the variety.
A fungus begins to develop on the spots immediately. It resembles black pads. The leaves on which they appeared turn yellow and fall off. This leads to the death of the plant.
The rose almost stops blooming. Usually, the affected plants can rarely survive the winter - they freeze out.
How to deal with black spot
The source of the appearance of this disease is the affected fallen leaves and shoots that have remained from last year.
Therefore, in order to avoid the development of the disease of other plants, it is necessary to collect the fallen leaves and burn them. If spotting appears on new shoots, they must be cut off immediately.
Do not be lazy, covering shrubs for the winter. To prevent black spots from appearing on the leaves of roses, take care of eliminating the sources of the fungus:
- Collect and burn the spotted leaves from the plants;
- Dig up the soil around the roses;
- Treat the plants with a fungicide.
It is best not to forget about ongoing prevention. It is necessary to spray the bushes with infusions of mullein or horsetail.
You can also take drugs that increase the resistance of plants to diseases. It can be zircon, immunodeficiency, "El", "Amulet". It is very effective to alternate spraying with preparations that contain mancozeb and triazole.
Spraying can be carried out once a week, and alternate preparations no more than three times. The effect of such plant treatment is very positive.
There is another way to get rid of stains - it will appeal to opponents of various drugs. A shovel can help in the fight against black spot.
If you plant a plant correctly and take care of it correctly, then this disease is unlikely to strike him.
If you want to protect your roses from spotting, then carry out the following manipulations:
- place them more freely;
- transplant to the sunniest place;
- remove the density;
- remove fallen leaves in a timely manner.
Mandatory treatment with copper sulfate, Bordeaux liquid or similar preparations in spring and autumn.
If the disease still touches the plants, make a strong pruning of the bush in the fall. Cut off the shoots at 2/3 of the bud from the base.
All this is guaranteed to reduce the damage to your favorite roses by harmful diseases.
A small speck appeared on the rose. It is easy to miss it, overlook it, overlook it. And that's all, the decorativeness of the rose is lost. How to recognize the disease in time and how to help it?
Types of spotting
The causative agents of all types of spotting on roses are usually various kinds of pathogenic fungi. It is difficult for a beginner to distinguish one disease from another. In most cases, it is not necessary, since protective and therapeutic agents usually have wide range actions. But if it is not possible to purchase a universal drug, then it would be good to recognize the disease.
Black spot (marssonina)
The causative agent of this disease is the mushroom Marssonina rosae. Its appearance is evidenced by dark spots, which over time merge into one continuous black spot... It is slightly swollen, the shape is irregular. The causative fungus is very fond of the cool, rainy weather, typical of early June and the second half of summer. Then you can see the first signs of this disease.
Downy mildew (downy mildew)
Brown spot
This disease is characterized by the appearance of brown, rounded spots with a diameter of up to 6 mm. There is a black border around the edges of the spots. Such spots are located on the upper side of the sheet. On the bottom, they are without a border, and their color is light brown. High temperature and humidity are favorable conditions for the development of this disease. Its causative agent is the Coryneum confusum mushroom.
Septoria blight (septoria leaf blight)
The leaves of a rose, affected by this disease, are covered with small round spots of a dark brown color on the upper side. Over time, they brighten, but the border remains brown. By autumn, the mushroom ripens, small black fruiting bodies - pycnidia appear in the center of the spot. At this stage, they overwinter on diseased leaves and shoots. The disease is caused by spores of the fungus Septoria rosae.
Greyish spotted rose (cercospora)
In this disease, the leaf becomes covered with brownish-purple small specks. Subsequently, the center of the spot turns gray, but the border remains brown. By autumn, black spherical pads appear in the center of the spots. Leaves turn yellow prematurely and fall off. The causative agent of the disease is the mushroom Cercospora rosiola.
Phyllostic spotting (phyllostictosis of leaves)
This is also a fungal disease. Its causative agent is Phyllosticta rosae. Signs: dark, brown spots with a purple border. Over time, the center of the spot brightens and becomes ashy. But the border is still wide, magenta... At the end, small black dots appear in the center.
Pestalocia
The leaves are attacked by the Pestalotia rosae fungus. First, brown spots appear along the edges of the leaf, which spread to the middle. There is a borderline yellow stripe between healthy and diseased tissue. Gray spore pads appear on the spots. On the shoots, depressed necrosis occurs, and gray spore pads also appear on them. Over time, necrosis expands, ulcers appear on the shoots, and they dry out.
Ascochitous spot
This spot is characterized by light, yellowish-white spots with a thin brown border. On these spots, by autumn, the wintering stages of the fungus are formed in the form of convex brown fruiting bodies. They hibernate on fallen diseased leaves. The name of the mushroom is Ascochyta rosicola.
Purple spot
It is excited by the fungus Sphaceloma rosarium. With this disease, many round purple or black spots with a crimson border appear on the upper side of the leaflet. The color of the border does not change over time, but the spot itself brightens, becomes ashy. On these upper spots, black fruiting bodies - pycnidia - are formed. There are stains on the underside of the leaf Brown color gradually merge. The leaf dries up and falls off. If the disease is not treated, then the spots go to the stems.
Leaf ramulariasis
With this disease, the leaves dry out, turn brown, brittle. It is called by spores of the fungus Ramularia banksiana. Spores form on the leaves in the form of small, white, crowded bunches.
Why is spotting dangerous?
But more than one plant will die. This fate can befall your entire rosary. Because the fungus multiplies with spores that move easily. They can be transferred from plant to plant by wind, rain, bees, various insects, even yourself. Therefore, when the first signs of the disease appear, urgent measures must be taken.
Treatment with folk remedies
Folk remedies are suitable only for the prevention of spotting. It will not be possible to cure the disease with their help, you will only waste your time in vain.
Carry out foliar dressing and preventive treatment in dry, calm weather in the evening. You do not need to store the prepared solutions, use them immediately.
For the prevention of fungal diseases, flower growers usually use the following means.
Iodine
- iodine - 1 ml;
- water - 400 ml.
Depending on the area to be treated, increase the volume of the solution proportionally.
Iodine whey
- serum - 1 liter;
- iodine - 10 drops;
- water - 10 liters.
Preventive treatment should be carried out twice at weekly intervals.
Garlic and Onion Hulls
- husk - 40 grams;
- water - 10 liters.
Pour the husk with water. Boil. Insist 8 hours. Water the bush liberally and shed soil around it. After the appearance of the buds, carry out preventive treatment. Try not to get on the petals, otherwise they may stain.
Mullein
After removing the winter shelter, but even before budding, pour over the bush with mullein infusion.
- mullein - 1 part;
- water - 9 parts.
Fill the mullein with water. Let the solution sit for 3 days. Strain the solution. Pour it over open bushes. It is at the same time protection against diseases and plant nutrition. During the growing season from May to July, you can carry out preventive treatments two more times. You just need to use a less concentrated infusion.
Fungicide treatment
Most effective method treatment of fungal diseases is the use of a combined method. It implies the following:
First, the diseased plant is treated with some kind of systemic fungicide. For example, a foundation. Prepare a solution in a ratio of 1 liter of water / 1 gram of substance. This solution should be evenly watered around the bush. Approximately 5 liters. It all depends on the size of the bush. On the same day, in the evening, spray the bush with the same solution. To obtain a homogeneous solution, you need to dilute the entire amount of the drug in a small amount of water. Then add the rest of the water.
After a week, the treatment is repeated. As a result, the pathogenic microflora will be almost completely destroyed.
After 18 days, the plant is treated with any biological fungicide. For example, phytosporin. Instructions for its use are indicated on the packaging. The need for its application is due to the fact that nature abhors a vacuum. In place of destroyed pathogenic fungi, it is necessary to populate useful ones, otherwise the territory will again be occupied by harmful fungi, and two species of protozoa cannot exist in one place. The protective effect of the biofungicide is based on this principle.
All fungicides are toxic. Therefore, take precautions when working with them. Work in a closed suit, gloves, glasses. It is advisable to have a respirator.
Bordeaux liquid (copper sulfate)
- drug - 10 grams;
- lime - 10 grams;
- water - 10 liters.
Carry out two treatments at weekly intervals.
The drug is very toxic. It should be used in a severe stage of the disease. The affected leaves will no longer recover, but the newly regrown ones will be healthy.
Abiga Peak (copper oxychloride)
- drug - 40 grams;
- water - 10 liters.
Two sprays are carried out after two weeks.
Previkur Energy
- drug - 1.5 ml;
- water - 1 liter.
To obtain a homogeneous solution, first stir the entire amount of the drug in a small amount of water, and then bring the volume to one liter. Prepare the solution one time. Increase the amount of water and the weight of the preparation proportionally. The plant is sprayed with this solution and the soil is shed at intervals of two weeks. Five treatments are possible.
Topaz
- drug - 4 ml;
- water - 5 l.
The interval of treatments is a week. Number - no more than three. The method for preparing the solution and processing the plant is the same as for Previkur Energy.
Speed
- drug - 2 ml;
- water - 10 liters.
The maximum number of treatments is three. The interval between them is a week.
Instead of this imported drug, you can use a domestic analogue under the trade name "Raek".
Profit Gold
- drug - 4 grams;
- water - 10 liters.
The maximum number of treatments is three. The interval between them is from eight to twelve days.
Ridomil Gold
This drug is effective against downy fungi. Two treatments are carried out after 10 days. Solution proportions:
- drug - 25 g;
- water 10 liters.
You cannot store the solution, you must use it immediately.
How to prevent spotting
It is more difficult to cope with a strong and healthy plant of the disease, its resistance is higher. Therefore, the florist's task is to provide proper care behind the plant.
Provide the right conditions for boarding
Plant flowers in a well-lit area. This will exclude high humidity which creates favorable conditions for the development of fungal diseases.
There is no need to plant roses on the south side, as pests that are dangerous to it and spread fungal diseases like to live there.
Do not thicken the planting. It is better if the stems of one plant will not come into contact with another. This will make it difficult for the fungal spores to spread.
Do not plant roses next to rose hips. These plants suffer from the same diseases, so a diseased rose hip can also infect roses.
Companions of roses can be lemon catnip, oak sage, lavender. They repel pests that can spread the mottling. Viburnum and lilac are considered bad neighbors for roses.
Inspect the plant regularly
The earlier treatment is started, the more successful it will be. Therefore, regularly inspect the leaves and stems of the roses. Pay attention to the spots that appear, remove the affected shoots. Thin thickened bushes so that moisture evaporates better.
Remove weeds
Prevent roses from growing in the weeds. Moisture is retained on them and fungi live, which can easily migrate to your favorite flowers. In addition, weeds need nutrients to grow. They take them from the soil by eating your roses.
Provide the right dose of fertilizer
The likelihood of the appearance of black spot increases with an excess of nitrogen fertilizers. In such conditions, the fungus feels comfortable and multiplies at a high speed.
Feed nitrogen fertilizers only in the spring. Also, the appearance of spotting on roses is facilitated by a lack of potassium, so carry out regular feeding with this fertilizer. You can use potassium salt, potassium sulfate, or wood ash... It is imperative to carry out potash fertilizing:
- in the end of May;
- At the beginning of June;
- at the end of July;
- in mid-August.
Treat roses with protective preparations
In the spring, after the roses open, but before the buds open, treat the rose and the ground under it with a 1% solution of Bordeaux liquid.
In May, after the leaves appear, spray the bush with a systemic fungicide, such as Strobi, to prevent spotting. Three treatments are carried out exactly ten days each. The first is 10 g of substance / 10 l of water. The second is 5 g of substance / 10 l of water. The third is 2.5 g of substance / 10 l of water.
From June to September, spray the plant with growth stimulants (Epin, Zircon). These funds strengthen the plant's immunity.
Before sheltering a rose for the winter, treat it and the ground around it with a 3% solution of ferrous sulfate.
Prune in time
In the spring, immediately after the opening of the roses, it is necessary to carry out sanitary and formative pruning. Treat the cuts with crushed charcoal.
With regular inspection of the bushes, remove excess or affected shoots as necessary.
In the fall, before covering the roses for the winter, cut off all the leaves, shorten the shoots, depending on the variety.
Disinfect the instrument
The fungus, the causative agent of black spot, can easily be transferred from plant to plant with the pruning tool. Therefore, it must be disinfected. For this, alcohol-containing or chlorine-containing agents are used. You can dip in a dark solution of potassium permanganate. Some use kerosene.
In the fall, harvest dry foliage and dig up the soil
The causative agents of black spot overwinter on fallen leaves affected by this disease and in the soil. Therefore, they must be removed and the soil must be dug up. It is better not to compost the leaves, but to burn them. If this is not done, they will winter safely and finish off the roses.
Choose varieties that are resistant to spotting initially
There are no absolutely invulnerable varieties, but breeders are working in this direction. They have developed varieties that are less susceptible to spotting disease. Spot-resistant roses with ADR mark. A variety testing system has been developed in Germany. According to her, the most hardy varieties this marking is assigned.
Healthy roses can be bought from German nurseries:
- Kordes;
- Noack;
- Tantau.
Floribunda and hybrid tea from the English nursery Fryer are also considered hardy.
What else do you need to know
Aside from spotting, there are many other diseases to be wary of. The most common:
Leaf spot is not typical for ornamental plants who are full of health. If you notice blotches of black, yellow, red or rusty hues on roses, they are most likely kept in unfavorable conditions or under stress. Discoloration of the leaves can also be a sign of a disease. How to find out why spots appeared on your pets and what measures to take to revive the plant?
The appearance of brown spots can be a sign of brown spot (cercospora). With such a disease, they also have a black border. Causes fungal disease connected with high temperature and humidity. The presence of dark brown spots may also indicate fungal infections such as septoria, pestalocin, phyllistiktosis.
The signs of all these diseases are similar to each other, so it will not be easy to make a definitive diagnosis. In this case, do not puzzle yourself, it is enough to carry out the processing chemicals to fight fungal diseases.
Black spots on roses
If June is cool and rainy, dark spots may form on the roses, which soon merge and turn black. Where they occur, swelling (rounded or oblong) can be observed. A disease of this kind is called black spot. The causative agent in this case is the mushroom Marssonina rosae. Soon the leaves fall off, the plant weakens and refuses to bloom. Black spot can be confused with downy mildew. However, the latter is characterized by spots different color(they can be black, red-brown, purple).
