Spots appeared on the rose petals. To avoid rose disease. How to spray roses for diseases: the best drugs

Roses of modern breeding are quite resistant to diseases, but the likelihood of their appearance cannot be ruled out, especially if a number of unfavorable factors coincide. These factors include: improper placement of the rose garden, errors in planting and caring for bushes, adverse weather conditions (excessive precipitation or lack of moisture, very coldy with poor shelter of plants, winter thaws, etc.). Plants weakened by pests also get sick. If signs of disease appear in the rose garden, a correct diagnosis should be made and timely treatment should be carried out.

Consider which diseases most often affect roses.

Diseases are divided into two groups: non-infectious and infectious.

Non-communicable diseases include diseases that are not transmitted from plant to plant and arise due to adverse conditions. environment. So, with a lack of moisture, the plants wither, when the roots get stuck on the leaves, yellow spots may appear, subsequently the leaves turn brown and fall off, root system dies and the plant dies.

An important factor is the mode of mineral nutrition.

So, with a lack of nitrogen, the leaves turn pale, shrink and fall prematurely, flowering worsens.

The leaves become light green or yellow, narrow, red dots appear in the middle. Shoot growth slows down. Plants need nitrogen primarily for their growth. Before flowering, roses kick out a lot of leaves. Add fast-acting nitrogen fertilizers for roses to the soil or water roses with herbal infusion.

With a lack of potassium, young leaves turn red, dry out at the edges and fall off.

The edges of young leaves turn brown and die. In winter, the shoots freeze, and the rose bush becomes easily ill. Potassium plays a huge role in the maturation of wood. The lack of potassium is caused by an increased content of lime, sand or peat in the soil. For the treatment of roses, it is necessary to apply no later than August to the soil potash fertilizer, better specially designed for roses.

Small leaves, dark green above and reddish below are symptoms of phosphorus deficiency.

Brown streaks form along the edges of rose leaves. purple tint stripes and spots, leaves fly around earlier, shoots grow weakly. Phosphorus is especially important for bud formation. The lack of phosphorus is often the result of liming of the soil. It is necessary to add peat to the soil, as well as feed the roses with superphosphate.

Leaves turning yellow is a sign of iron deficiency.

The leaves turn yellow, but their veins remain green. Young leaves turn yellow first. Iron deficiency can manifest itself, for example, with constantly damp or calcareous soil, which makes it difficult for roses to absorb this trace element. It is useful to spray the leaves with a solution of ferrous sulfate or complex organic compounds gland.

Magnesium deficiency is manifested by the death of tissues along the central vein of old leaves, which fall prematurely.

First, signs of the disease appear on older leaves, then on younger ones. Dead, reddish-yellow spots are visible between the veins, the edges of the leaves remain green. After a while, the leaves fall off. Magnesium is necessary for roses for metabolism, sometimes it is not absorbed due to an excess of potassium. Add magnesium sulfate to the soil.

Chlorosis between the veins is a sign of manganese deficiency.

Between the veins of the leaves, starting from the edges and to the central vein, yellow spots extend. Older leaves are most often affected. Manganese is contained in special fertilizers (manganese sulfate, potassium permanganate) that must be applied to the soil.

To maintain the balance of minerals, it is necessary to apply specialized fertilizers for roses in spring and autumn.

An excess of nitrogen can cause the growth of strong shoots that do not produce flowers (fatty shoots). Such shoots need to be shortened by 1/3, which will serve as branching and the formation of flower buds.

If possible, it is useful to do a soil analysis in a specialized laboratory and get recommendations on the application of the necessary fertilizers.

Infectious diseases are divided into fungal, bacterial and viral.

Fungal diseases

powdery mildew

The causative agent is the fungus Sphaerotheca pannosa.

Leaves, stems and buds are covered with a whitish-gray, easily removed bloom, which often appears after sunny days with abundant morning dew. Defeat powdery mildew can be prevented by planting roses in a ventilated area and spraying them regularly in dry weather with a copper-soap emulsion or colloidal sulfur. Sick shoots are cut and burned.

The first characteristic sign is the appearance of a white powdery coating on the leaves, stems and buds. Over time, this plaque becomes denser, acquires a grayish color, black fruiting bodies of the fungus appear on it. The spores are easily carried by the wind and can infect other plants. The defeat of powdery mildew extremely adversely affects the condition of the plant. The decorative effect is sharply reduced, the affected leaves and buds curl, dry up and fall off, the shoots bend and die.

Powdery mildew can develop even in dry and warm weather. Diseases are not subject to resistant varieties and roses growing in the shade.

Control measures: at the first signs of the disease, treat with systemic fungicides, while changing the drugs so that addiction does not occur. So, for example, Topaz or Skor can be alternated with Quadris or Fundazol. Processing is carried out every 10-14 days until the signs of the disease disappear.

In autumn, all damaged leaves and shoots must be burned.

leaf spot

Several diseases related to spotting are known: black spotting, peronosporosis (downy mildew), cercosporosis (grayish spotting), phyllosticosis, brown spotting, purple spotting and others. The most dangerous and common are black spot and downy mildew.

black spot

The causative agent of the disease: the fungus Marssonina rosae

affects leaves, sometimes green shoots. The disease is manifested by the formation of small spots on the upper side of the leaves, which then grow, become almost black. Affected leaves curl and fall off, only bare shoots remain, plants weaken, grow poorly, do not bloom. Severe infection can lead to the death of the plant.

Control measures: alternate treatment with systemic fungicides containing different active ingredients. For example, Topaz or Skor alternate with Ridomil Gold or Quadris with an interval of 10 - 14 days. The number of sprays - 2-3 times.

Downy mildew (Peronosporosis)

The causative agent is the fungus Pseudoperonospora sparsa.

The initial stages of the development of the disease resemble black spot. Young leaves are covered with brown-violet spots, which can go on the shoots. On adult leaves, areas with a pale color first appear, then they turn brown, dry out and fall off. On the underside of the leaf, a grayish coating can be seen.

Downy mildew can be distinguished from black spot by the nature of the fall of the leaves: with downy mildew, they begin to fall from the top of the shoot, and with black spot from the bottom.

cool, rainy weather contributes to the development of the disease.

Control measures: spraying with fungicides (Ridomil-Gold, Fundazol, Skor, Strobi, Quadris, Profit are effective).

Damaged leaves and parts of the plant are removed and burned.

*Other diseases from the group of spotting are similar in their manifestations and are treated according to the same algorithm as black spot.

Rust

The causative agent is the rusty Phragmidium disciflorum.

A dangerous disease manifests itself in early summer by the appearance of bright orange tubercles (pycnidia) at the base of young shoots and reverse side leaves, which, growing, become rusty-brown. Autumn spots on outside leaves turn black, and on the bottom they become brown-brown. As a result, leaves on diseased plants fall off, young shoots become deformed, crack and dry out. The disease leads to a strong weakening of the plant and even its death.

Control measures: alternate spraying with fungicides with different active ingredients. For example, apply Skor (active ingredient difenoconazole), and then Ridomil-Gold (active ingredient mancozeb). Falcon treatment is also recommended.

Damaged leaves and shoots are burned.

For prevention, bushes are treated in the spring with a contact fungicide "Maxim", or Bordeaux liquid (1%).

Infectious burn

The causative agent is the marsupial fungus Coniothyrium wernsdorffiae.

Symptoms of the disease: encircling red-brown spots appear on last year's shoots in spring. The bark on such shoots dries up, cracks, ulcers appear on it, infected shoots subsequently die.

The appearance of the disease contributes high humidity in winter shelters and excessive application of nitrogen.

Control measures: spring pruning and burning of diseased shoots, treatment of bushes with Bordeaux mixture, fungicide "Maxim".

To prevent the disease, the following rules should be observed: cover roses in dry, cool weather, remove all leaves and unripe shoots before sheltering, ventilate shelters during winter thaws, open bushes in a timely manner in spring, use disinfected tools for pruning.

Gray rot or botrytis

The causative agent is the fungus Botrytis cinerea.

Symptoms: brown spots without bordering with a gray coating of sporulation of the fungus on leaves and shoots. When spores hit the petals, small spots first appear, which grow and turn brown. The flowers rot, covered with a gray bloom.

Wet, cool weather favors disease. If the rules for sheltering roses for the winter are not followed, the disease can severely affect the bushes under shelters.

Control measures: treatment with fungicides (Fundazol, Falcon, Maxim), timely removal and destruction of infected parts of the plant.

Preventive treatment with Maxim, or Bordeaux liquid.

Bacterial diseases

The most common bacterial diseases are root canker and stem canker.

Bacterial root cancer

The causative agent is the bacterium Agrobacterium tumefaciens.

Symptoms: dense growths form on the roots and root neck, which rot as bacteria multiply. Affected plants become weak, stunted and eventually die.

Control measures: cutting off the affected parts and disinfection with a 1% solution blue vitriol. The fight should be carried out in the early stages of the development of the disease, heavily infected plants should be burned.

Prevention: diseased seedlings should be discarded, in areas where infected roses grew for 3-4 years, do not plant new bushes, because. bacteria persist in the soil.

Bacterial stem cancer

The causative agent is the bacterium Pseudomonas syringae

Symptoms: first depressed brown spots appear on the bark of the shoots, then these parts of the bark die off, the shoots gradually dry out. The leaves of diseased plants are covered with dark spots. Weakened plants are susceptible to the disease.

Control measures: removal and burning of infected shoots. Cut the shoots to healthy tissue, disinfect with a 5% solution of copper sulfate, or Maxim, cover the sections with oil paint. Severely affected plants should be completely destroyed.

Prevention: spraying the bushes in the spring (before the leaves bloom) and before winter shelter copper sulfate solution or 1% Bordeaux mixture or "Maxim".

Viral diseases

Sometimes on the leaves of roses you can notice the appearance of a pale color in the form of mosaic or ring spots, speckled edging of the veins - all these are signs of plant damage by viruses.

Viral diseases include various types of mosaic diseases, wilting diseases, jaundice, dwarfism, etc.

Viruses can be introduced with planting material, they are spread by insects, as well as through garden tools.

There are quite a few viral diseases, but we will give only the most common ones.

leaf striping

The causative agent is Rose streak virus.

It is characterized by the following symptoms: brown rings and speckled borders of veins on young leaves, vague stains and greenish spots. Brown on the run. Diseased plants lag behind in growth, bloom poorly

Viral wilt

The causative agent is Rose wilt virus.

Young shoots grow, the leaves become narrow, up to filiform, gradually turn brown and dry. Buds do not form, the bushes lag behind in growth and gradually dry out.

In addition, roses are affected by tobacco necrosis viruses, rhubarb mosaic, apple tree mosaic, tomato bronze, plum necrotic ring spot and some others. Often plants are affected by two viruses at once.

There is no point in mentioning all possible viral diseases, their determination is only possible for specialists, in addition, there are no effective measures to combat them, therefore, measures are reduced to the removal of damaged parts, or the entire plant in case of severe infection and their subsequent burning. garden tools after use, disinfect in alcohol or 1% potassium permanganate solution.

Harmful insects:

rose cicada

The rose cicada first settles on the veins, and then spreads over the entire surface of the leaf. small insects suck the juices from the underside of the leaves. Most often they appear in dry weather. Affected leaves dry up and fall off. Spraying with pyrethrum helps, and with an increase in the number of pests, treatment with Intavir or a similar preparation is recommended.

spider mite

Small sucking pest (0.3-0.4 mm) greenish-yellow, wintering females orange-red. Ticks large colonies settle on the underside of the leaves. They multiply very quickly in hot and dry summers and with an excess of fertilizers. Spraying with herbal infusions helps well against spider mites. in dry and hot weather spray roses often with water.

rose sawflies

The yellow-green caterpillars of the descending sawfly bite into young shoots in spring and make moves inside from top to bottom. As a result, the shoots die off. In summer, on the stems, you can see holes with a white crumb inside, made from the bottom up by a brownish sawfly caterpillar. Affected shoots are pruned and destroyed.

rose leaf

From May, rolled, withered leaves begin to appear. Inside them are small caterpillars with a brownish head. Affected leaves are collected and destroyed. To control insects, it is recommended to attract birds to the garden. With a strong reproduction of leafworms, it is recommended to use chemical protection products that are harmless to bees.

rose aphid

Settles on buds and leaves. The buds do not open and fade, the leaves and young shoots are bent and covered with a sticky mass, and some time later a black soot fungus appears on it. In case of mild infestation, aphids can be washed off with water or wiped with a cloth. With a strong defeat of the rose, it is necessary to spray the plants with an insecticide against sucking pests.

Golden bronze and garden beetle - small beetles that eat stamens, pistils and flower petals, penetrate into buds, which form ugly flowers or their halves. Rose flowers lose their decorative effect or do not open at all. Beetles are collected and destroyed whenever possible. It is better to do it in the morning. Affected shoots are pruned.

Weather
Freezing

Spring frosts at the beginning of the growing season sometimes cause very significant damage to roses. In frozen plants, the edges of the leaves turn brown and dry, and then curl. Bushes do not unravel until the onset of sustained heat. So that roses do not suffer from a lack of moisture and do not dry out, in a relatively warm weather don't forget to water them.

Stagnant water in the soil

The leaves turn yellow, starting from the petiole, and fall off. As a rule, this occurs in damp, heavy, dense soil, and also as a result of excessive watering. Water squeezes air out of the soil, and the roots rot. Plants under such conditions are more likely to be attacked by pests or get sick. In heavy soils, sand should be added and loosened regularly.

Finally. To admire healthy and beautiful bushes roses in your garden, you need to take care of disease prevention. First of all, roses need to be planted in well-lit and ventilated areas, on rich soils, properly fertilize, treat pests, and prune correctly. For the prevention of fungal diseases in the spring, treatment with the contact action fungicide "Maxim" or a 1% solution of Bordeaux mixture is recommended.

To increase the immunity of plants, treatment with Epin, Zircon, Lignohumate has proven itself.

If you want to have as much as possible less problems with diseases, purchase new, resistant varieties of roses.

Roses of modern breeding are quite resistant to diseases, but, with a confluence of adverse factors, it is impossible to completely exclude the possibility of infection.

These factors include: improper placement of the rose garden, errors in planting and care, adverse weather conditions such as: excessive rainfall or lack of moisture, severe frosts with poor shelter, winter thaws.

And also pests. In this article, we will look at what diseases most often affect roses. Having studied certain signs of diseases, it will be easier for you to correctly diagnose your roses and carry out timely treatment.

Symptoms

Reddish-black spots appear on the shoots, sometimes with a light brown dry area in the center of the burn. A crimson border is visible along the edge of the spot. These spots in the spring with poor ventilation quickly increase in size, ring the shoot, which dries up.

Treatment

In order to avoid the spread of the disease, it is better to cut off the affected shoots. If the damage is small, and the shoot is very pitiful (for example, in a single-flowering rose), you can try to leave a branch, but watch it very carefully to prevent, for example, damage to the graft - after opening the roses and establishing warm weather, the spread of the disease quickly stops, and burn spots "freeze".

Such branches can be pruned after flowering in summer. Such small spots can be tried and treated - cleaned sharp knife to healthy tissue and cover with Runnet.

downy mildew

Symptoms

The causative agent is the fungus Pseudoperonospora sparsa. The bark of the shoots cracks, becomes covered with "sores". Small red-brown or purple spots of an angular shape (with straight sides of the spot) appear on young leaves, the leaf is gradually deformed.

If the spot reaches the central vein of the leaf, it immediately falls off. Purple spots may also appear on shoots. On adult leaves, the leaf tissue becomes faded and soft in places, the color does not change, then this spot quickly becomes red-brown and dries, the leaves turn yellow and fall off, the flowers and buds are deformed.

From the inside, a barely noticeable grayish coating sometimes appears (it can often be seen only with a magnifying glass). The outer petals of the buds turn black and fall off. Bushes lag behind in growth. The development of the disease is facilitated by high humidity and cool weather; in dry and hot times, the disease subsides. Downy mildew is fairly easy to confuse with black spot.

The difference is that with downy mildew, the plant usually loses leaves from top to bottom (with black spot - vice versa). At the same time, the fall is very fast, literally in a couple of days.

Treatment

Affected shoots must be cut and burned (the fungus overwinters in young shoots). The causative agent in biology is close to phytophthora fungi, therefore drugs against phytophthora (Profit, Ridomil Gold) are also effective against downy mildew. As a preventive measure, plants are fed with phosphorus and potash fertilizers.

powdery mildew

Symptoms

The causative agent is the fungus Sphaerotheca pannosa. Reddish-purple spots appear on young leaves on young leaves, often the leaves are deformed. Buds, shoots, leaves are covered with powdery white bloom, the leaves curl and fall off. On varieties with coarser leathery leaves sometimes mosaic coloring or wrinkling is observed.

The most rapid development of the fungus and the germination of its spores (conidia) occur at 18-20C and humidity above 60%. Often, during the growing season, 2-3 outbreaks of the disease are observed, which is associated with suitable conditions or re-growth of shoots (powdery mildew affects mainly young tissues).

Treatment

Compliance with the correct agricultural technology - do not overfeed roses, plant in well-ventilated places. Prevention is desirable - roses are regularly sprayed with infusion of mullein or ash (these infusions destroy the threads of the mycelium). For treatment, in addition to the mullein solution, it can be sprayed with triazole-based fungicides (Topaz, Skor).

As a prophylactic, you can try a preparation based on rapeseed oil ( Carbon Impact® Surfactant), it is sold at the Ulyanovsk state farm of decorative floriculture, but quite expensive (a canister costs about 5,000 rubles). According to the feedback of employees, it helps perfectly (oil with an emulsifier forms a hard-to-wash off oil on the sheet). protective film, which prevents fungi from penetrating the leaf tissue).

Rust

Symptom

The causative agent is fungi of the genus Phragmidium. Rust fungi have several stages of development, the symptoms of damage in which differ from each other. In late April-early May, yellow-orange tubercles of the spring (ecidial) stage of the fungus appear on the stems at the opening buds, on young green shoots, petioles and the upper side of the leaves.

Dusty pustules form on the underside of the leaves, from where the spores of the fungus are carried to healthy plants. As a result, the leaves turn yellow and fall off, young shoots bend and dry out. In July, the uredostage develops, which is characterized by the appearance of small rusty-brown pustules on the underside of the leaves. Yellow and reddish spots on the upper side of the leaf, growing, cover its entire area.

The shoots thicken, deform and crack, which is accompanied by a mass of dusting spores. At the end of August-September, the pustules darken - a tel-tostage develops in them, in the form of which the fungus overwinters in the affected stems and fruits.

The last two stages can significantly reduce the growing season of roses, which leads to a decrease in growth, premature drying of leaves, weakening of plants, and in severe cases, to their death. contributes to the development of the disease high humidity especially during the early growing season. Hot, dry weather inhibits the development of the disease.

Treatment

Rust is difficult to treat. It is necessary to cut and burn all the affected parts of the plant - in no case put them in the compost! For prevention, before each flowering, it is necessary to carry out foliar top dressing 0.3% superphosphate extract solution and 0.3% potassium nitrate solution until the leaves are completely wetted.

For treatment, you can try alternate treatment with preparations containing mancozeb (Ridomil Gold, Profit) and penconazole (Topaz), as with black spot - but they are also more effective in early spring, as a preventive measure.

There is information that fungicides containing the active ingredients tebuconazole and triadimefon (Bayleton, Folicur, Falcon) also work, but all these preparations are not for home gardening, and their effect on roses has not been tested. With severe damage, plants are not subject to treatment. They are dug up and burned. Fortunately, in the climate near Moscow, this disease is rare.

Gray rot

Symptoms

The causative agent is the fungus Botrytis cinerea. Wintering shoots of bushes from the side of the upper cut rapidly turn brown from top to bottom and die. At high humidity, the shoots are covered with fluffy smoky gray mycelium.

Areas of tissue become brown, and in wet weather become covered with a gray coating. Green shoots dry out completely, flower stems break. Sick buds do not bloom or give one-sided flowers. Densely double varieties are especially affected by gray rot.

Treatment

The disease develops strongly with high humidity of air and soil, dense planting, lack of phosphorus and potassium in the soil. At the first signs of the disease, it is necessary to create conditions for maximum dryness near the plants, feed them with phosphorus-potassium fertilizers in a ratio of 2: 1 for the active substance, adding manganese microfertilizers.

Symptoms

The causative agent is the fungus Botrytis cinerea. appear on the stems dark spots, buds and flowers are covered with a dark gray bloom, the outer petals turn brown and dry, the flowers fall prematurely.

First of all, rot attacks weakened plants, and most often with white and light pink flowers. Small brown spots (sores) appear on the petals, the leaves turn yellow and also fall off.

Treatment

The disease progresses in rainy weather, especially among varieties with soft tender petals. In order to avoid the appearance of rot on the flowers, roses are not watered by sprinkling, but during the rainy season they are fed with manganese-containing fertilizers, damaged flowers and buds are immediately removed, trying to prevent rotten petals from falling on the leaves.

Unfortunately, a number of varieties are susceptible to such flower damage, and in rainy weather you will not be able to see them in all their glory. These are, for example, varieties Colette, Andre le Notre, Eden Rose, Sebastian Kneipp and others.

Symptoms

The disease is caused by a fungus of the genus Cercospora. Numerous purple-brown oval spots appear on the leaf surface. Later, the center of the spot turns gray, and the edging remains dark purple.

Leaves heavily affected by spotting turn yellow and fall off. The disease is easily confused with black spot, which is very similar.

Treatment

leaf septoria

Symptoms

The causative agent of spotting is a fungus of the genus Septoria. On the upper side of the leaves, whitish or dark gray spots appear, large, rounded, merging with each other.

The spots are limited by a thin dark red border. By autumn, black dotted fruit bodies - pycnidia - form in the center of the spots.

Treatment

Treatment measures are the same as for black spot.

purple spotting

Symptoms

The causative agent is a fungus of the phyllosticta genus. On the upper side of the leaves, rounded purple, sometimes even black spots are formed, bordered by a wide crimson stripe and gradually brightening in the center.

Small black fruiting bodies - pycnidia - form on the spots. On the underside of the leaf blade, the spots are brown, merging. Affected leaves fall off, flowers are underdeveloped. With a strong spread of the disease, dark brown spots with a white center appear on green shoots.

Treatment

Treatment measures are the same as for black spot.

black spot

Symptoms

The causative agent is the fungus Marssonina rosae. In the second half of summer, black spots appear on the leaves, the lower leaves quickly turn yellow and fall off. With a strong defeat, only young unblown leaves remain on the roses.

Treatment

Prevention is desirable against this disease - spraying with infusions of mullein, horsetail. You can also use drugs that increase the plant's resistance to diseases (zircon, immunophycyte, El, Amulet).

A very good recommendation was given on the Websada forum - for treatment, alternate spraying with preparations containing mancozeb (Profit, Ridomil Gold) and triazole (Topaz, Skor) is effective at a weekly interval (alternate no more than three times). Feedback on this treatment regimen is very positive.

Bark breaks

Symptoms

In the spring, longitudinal ruptures of the bark appear on overwintered shoots. Typically, such breaks appear after a wet winter or autumn, often under a hillock (for example, when a rose was covered with wet sand).

Treatment

If the breaks are fresh, you can try to carefully "bandage" them with a cellophane ribbon cut from the bag. The bark will grow quickly and in the middle of summer the bandage can be removed (the main thing is to do it on time so that a constriction does not form on the thickening shoot.

You can try and spray the gaps on the bark with “Charm” varnish (it is this brand - it contains natural components) - I haven’t tried it myself, but they say it helps well. Small gaps can not be touched - they will overgrow themselves. But it is better to cut off the strongly “soaked” branches - they will dry out anyway.

Symptoms

Quite often in spring, open roses shoots become uniform brown. There are several options for darkening: 1) upper layer the bark is a little frostbitten, or propped up in a warm and humid winter 2) the shoot just “tanned” in the hot spring sun. In this case, it is usually not evenly brown, but only from one "side".

Treatment

Usually, such shoots develop normally, because. the damage is small. With signs of drying out, it is better to cut the branch.

Symptoms

The young shoot of the rose freezes, does not grow. The crown of the shoot ends with a thickening; there are no rudiments of buds or leaves on it. Lateral growths do not appear, and the shoot itself thickens over time, becomes ugly.

More often, blind shoots do not grow from the base of the bush, but from a bud on the main shoot. The reason for the appearance of such shoots is usually frost damage to the apical bud, or adverse weather conditions.

Roses of modern breeding are quite resistant to diseases, but the likelihood of their appearance cannot be ruled out, especially if a number of unfavorable factors coincide. These factors include: incorrect placement of the rose garden, errors in planting and caring for bushes, adverse weather conditions (excessive precipitation or lack of moisture, severe frosts with poor plant shelter, winter thaws, etc.). Plants weakened by pests also get sick. If signs of disease appear in the rose garden, a correct diagnosis should be made and timely treatment should be carried out.

Consider which diseases most often affect roses.

Diseases are divided into two groups: non-infectious and infectious.

Non-infectious diseases include diseases that are not transmitted from plant to plant and arise due to adverse environmental conditions. So, with a lack of moisture, the plants wither, when the roots get stuck on the leaves, yellow spots may appear, subsequently the leaves turn brown and fall off, the root system dies and the plant dies.

An important factor is the mode of mineral nutrition.

So, with a lack of nitrogen, the leaves turn pale, shrink and fall prematurely, flowering worsens.

With a lack of potassium, young leaves turn red, dry out at the edges and fall off.

The edges of young leaves turn brown and die. In winter, the shoots freeze, and the rose bush becomes easily ill. Potassium plays a huge role in the maturation of wood. The lack of potassium is caused by an increased content of lime, sand or peat in the soil. For the treatment of roses, it is necessary to introduce potash fertilizer into the soil no later than August, better specially designed for roses.

Small leaves, dark green above and reddish below are symptoms of phosphorus deficiency.

Along the edges of the leaves of roses, brown stripes and spots with a purple tint are formed, the leaves fly around earlier, the shoots grow weakly. Phosphorus is especially important for bud formation. The lack of phosphorus is often the result of liming of the soil. It is necessary to add peat to the soil, as well as feed the roses with superphosphate.

Leaves turning yellow is a sign of iron deficiency.

Magnesium deficiency is manifested by the death of tissues along the central vein of old leaves, which fall prematurely.

Chlorosis between the veins is a sign of manganese deficiency.

To maintain the balance of minerals, it is necessary to apply specialized fertilizers for roses in spring and autumn.

If possible, it is useful to do a soil analysis in a specialized laboratory and get recommendations on the application of the necessary fertilizers.

Infectious diseases are divided into fungal, bacterial and viral.

Fungal diseases

powdery mildew

The causative agent is the fungus Sphaerotheca pannosa.

Leaves, stems and buds are covered with a whitish-gray, easily removed bloom, which often appears after sunny days with heavy morning dews. Powdery mildew can be prevented by planting roses in a ventilated area and spraying them regularly in dry weather with a copper-soap emulsion or colloidal sulfur. Sick shoots are cut and burned.

Powdery mildew can develop even in dry and warm weather. Diseases are susceptible to non-resistant varieties and roses growing in the shade.

In autumn, all damaged leaves and shoots must be burned.

leaf spot

black spot

The causative agent of the disease: the fungus Marssonina rosae

Downy mildew (Peronosporosis)

The causative agent is the fungus Pseudoperonospora sparsa.

Downy mildew can be distinguished from black spot by the nature of the fall of the leaves: with downy mildew, they begin to fall from the top of the shoot, and with black spot from the bottom.

Cool, rainy weather promotes the development of the disease.

Control measures: spraying with fungicides (Ridomil-Gold, Fundazol, Skor, Strobi, Quadris, Profit are effective).

Damaged leaves and parts of the plant are removed and burned.

*Other diseases from the group of spotting are similar in their manifestations and are treated according to the same algorithm as black spot.

Rust

The causative agent is the rusty Phragmidium disciflorum.

A dangerous disease manifests itself in early summer by the appearance of bright orange tubercles (pycnidia) at the base of young shoots and the back of the leaves, which, growing, become rusty-brown. In autumn, the spots on the outer side of the leaf turn black, and on the underside they become brown-brown. As a result, leaves on diseased plants fall off, young shoots become deformed, crack and dry out. The disease leads to a strong weakening of the plant and even its death.

Damaged leaves and shoots are burned.

For prevention, bushes are treated in the spring with a contact fungicide "Maxim", or Bordeaux liquid (1%).

Infectious burn

The causative agent is the marsupial fungus Coniothyrium wernsdorffiae.

Symptoms of the disease: encircling red-brown spots appear on last year's shoots in spring. The bark on such shoots dries up, cracks, ulcers appear on it, infected shoots subsequently die.

The appearance of the disease is promoted by increased humidity in winter shelters and excessive nitrogen application.

Control measures: spring pruning and burning of diseased shoots, treatment of bushes with Bordeaux liquid, Maxim fungicide.

Gray rot or botrytis

The causative agent is the fungus Botrytis cinerea.

Wet, cool weather favors disease. If the rules for sheltering roses for the winter are not followed, the disease can severely affect the bushes under shelters.

Control measures: treatment with fungicides (Fundazol, Falcon, Maxim), timely removal and destruction of infected parts of the plant.

Preventive treatment with Maxim, or Bordeaux liquid.

Bacterial diseases

The most common bacterial diseases are root canker and stem canker.

Bacterial root cancer

The causative agent is the bacterium Agrobacterium tumefaciens.

Symptoms: dense growths form on the roots and root neck, which rot as bacteria multiply. Affected plants become weak, stunted and eventually die.

Control measures: pruning of the affected parts and disinfection with a 1% solution of copper sulfate. The fight should be carried out in the early stages of the development of the disease, heavily infected plants should be burned.

Prevention: diseased seedlings should be discarded, in areas where infected roses grew for 3-4 years, do not plant new bushes, because. bacteria persist in the soil.

Bacterial stem cancer

The causative agent is the bacterium Pseudomonas syringae

Prevention: spraying the bushes in the spring (before the leaves bloom) and before the winter shelter with a solution of copper sulfate or 1% Bordeaux mixture or "Maxim".

Viral diseases

Sometimes on the leaves of roses you can notice the appearance of a pale color in the form of mosaic or ring spots, speckled edging of the veins - all these are signs of plant damage by viruses.

Viral diseases include various types of mosaic diseases, wilting diseases, jaundice, dwarfism, etc.

Viruses can be introduced with planting material, they are spread by insects, as well as through garden tools.

There are quite a few viral diseases, but we will give only the most common ones.

leaf striping

The causative agent is Rose streak virus.

It is characterized by the following symptoms: brown rings and speckled borders of the veins on young leaves, blurry stains and greenish-brown spots on the shoots. Diseased plants lag behind in growth, bloom poorly

Viral wilt

The causative agent is Rose wilt virus.

Young shoots grow, the leaves become narrow, up to filiform, gradually turn brown and dry. Buds do not form, the bushes lag behind in growth and gradually dry out.

It makes no sense to mention all possible viral diseases, only specialists can determine them, in addition, there are no effective measures to combat them, therefore, measures are reduced to removing damaged parts, or the entire plant in case of severe infection and their subsequent burning. Garden tools after use are disinfected in alcohol or 1% potassium permanganate solution.

Harmful insects:

rose cicada

The rose cicada first settles on the veins, and then spreads over the entire surface of the leaf. Small insects suck the juices from the underside of the leaves. Most often they appear in dry weather. Affected leaves dry up and fall off. Spraying with pyrethrum helps, and with an increase in the number of pests, treatment with Intavir or a similar preparation is recommended.

spider mite

Small sucking pest (0.3-0.4 mm) greenish-yellow, wintering females orange-red. Ticks settle in large colonies on the underside of the leaves. They multiply very quickly in hot and dry summers and with an excess of fertilizers. Spraying with herbal infusions helps well against spider mites. In dry and hot weather, spray roses more often with water.

rose sawflies

rose leaf

rose aphid

Weather
Freezing

Spring frosts at the beginning of the growing season sometimes cause very significant damage to roses. In frozen plants, the edges of the leaves turn brown and dry, and then curl. Bushes do not unravel until the onset of sustained heat. In relatively warm weather, do not forget to water the roses so that they do not suffer from a lack of moisture and do not dry out.

Stagnant water in the soil

Finally. To enjoy healthy and beautiful rose bushes in your garden, you need to take care of disease prevention. First of all, roses need to be planted in well-lit and ventilated areas, on rich soils, properly fertilize, treat pests, and prune correctly. For the prevention of fungal diseases in the spring, treatment with the contact action fungicide "Maxim" or a 1% solution of Bordeaux mixture is recommended.

To increase the immunity of plants, treatment with Epin, Zircon, Lignohumate has proven itself.

If you want to have as few disease problems as possible, get new, resistant varieties of roses.

Fungal disease of roses powdery mildew in the photo

With a fungal disease of roses, powdery mildew appears on young leaves, shoots and buds; there is a thickening and curvature of them.

As you can see in the photo, powdery mildew on roses appears as a whitish bloom, which is a mycelium and sporulation of the fungus:

Powdery mildew on roses
Powdery mildew on roses appears as a whitish bloom (photo)

The causative agent of the disease overwinters in the form of mycelium in the kidneys. The development of the disease contributes to excessive nitrogen fertilizer, lack of calcium in the soil, drying out of the soil, too light sandy or, conversely, cold damp soils.

The disease develops especially strongly with insufficient lighting and high humidity. A sharp change in temperature, drafts, drying out of the earth and other conditions that disrupt the normal life of plants reduce their resistance to disease. Tea and hybrid tea roses with more delicate foliage are especially affected.

Resistant to powdery mildew are varieties of roses that have dense glossy leaves of the "Gloria Day" type.

For the treatment of powdery mildew on roses, when the first signs of the disease appear, it is necessary to spray the bushes with "Topaz", "Pure Flower", "Fundazole" or "Soon". At temperatures above 22 ° C, it is possible to spray with "Grey colloid" or "Thiovit Jet". If necessary, to combat this rose disease, treatments are repeated as young growth and powdery mildew spots appear on them.

Rust of roses in the photo

With this disease of roses in flowers, the affected parts of the shoots are bent and thickened. In spring, orange dust appears on the stems at the opening buds and at the root neck. These are spring sporulation of the fungus - the causative agent of the stem form of rust. The fungus overwinters in the tissues of plants infected in previous years. The disease develops more intensively in years with a warm and humid spring.

Rust fungi not only take away nutrients in a plant, but also greatly disrupt its physiological functions: they increase transpiration, reduce photosynthesis, make breathing difficult and worsen metabolism.

In rose rust disease, small, red-yellow pads of summer spores form on the leaves on the underside in summer, 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.

Look at the photo - if this rose disease has severely affected the plant, the leaves turn completely yellow and fall prematurely:

Affected parts of rose shoots (photo)
In case of rose disease, rust on the leaves on the underside in the summer forms small, red-yellow pads of summer spores (photo)

The spread of rust fungus spores occurs with air flow, water, and planting material.

To protect roses from this disease, one-way 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.

For the treatment of rose rust, it is necessary to carefully and timely cut off the shoots affected by the stem form of rust, from the moment the buds open, re-spray the plants with Bordeaux mixture (1% ) or its substitutes (“Oksihom”, “Abiga-Peak”, “Hom”, “ Copper oxychloride”, “Ordan”).

Rose leaf disease black spot in the photo

Rose disease black spot is also called marsonine by the name of the fungus - the causative agent of the disease. In the second half of summer, dark brown, almost black, spots form on the leaves. different sizes. The leaves turn brown and often fall prematurely. Spots may also appear on the green bark of annual shoots.

Plants with prematurely fallen leaves sometimes begin to grow again, as a result of which they are greatly weakened and bloom poorly the next year.

Under the skin of the leaves, the mycelium of the fungus develops - the causative agent of the rose spot disease, which forms radiantly growing bands.

As can be seen in the photo, with this disease of roses, radiance is clearly visible at the edge of the spots:

With this disease of roses, radiance is clearly visible at the edge of the spots (photo)
Under the skin of the leaves, the mycelium of the fungus develops - the causative agent of rose spot disease (photo)

This disease of rose leaves is more pronounced with a dense planting, in shaded places, with poor ventilation of the site.

Measures to combat this disease include:

proper agricultural technology that increases the resistance of plants;
careful collection and fall of the affected leaves and burning them;
spraying plants during the growing season with preparations containing copper, which are used in the fight against rust.
for the treatment of this disease of roses, it is recommended to use a special preparation for spraying (Skor for the protection of roses), which is a systemic fungicide of preventive and curative action.

Treatments should be started at the first signs of the disease and repeated after each rain or heavy dew.

These photos show how to treat rose disease black spot:

Rose bacterial cancer disease in the photo

At bacterial cancer roses on the root collar and roots of plants, growths of various sizes are formed. Sometimes they are barely noticeable, but often reach several centimeters in diameter. The growths have an uneven tuberculate surface. They consist of soft tissue, first white, then brown and decomposed by bacteria in the soil.

There are also hard lignified growths that grow every year. The aerial part is less often affected - trunks and branches, mainly in climbing and standard remontant roses. Here tuberculate nodules and tumors of various sizes are formed.

bacteria, cancer-causing, affect 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 soil moisture, abundant manure fertilizer, damage to the roots, alkaline soil reaction.

When transplanting plants with an affected root neck, they must be destroyed, and the growths on the lateral roots should be cut off. To treat this disease of roses, after pruning, the roots are immersed for 5 minutes in a 1% solution of copper sulfate, and then washed in water and dipped in a liquid mixture of clay and sand. Avoid excess manure fertilizer, kill insects that damage the roots, do not dig the soil near the bushes.

Look at the photo of rose cancer treatment:

Fungal disease burn branches of roses in the photo

Branch burn is fungal disease, in which, on the branches, reddish spots appear at first, later darkening in the middle; red-brown edging persists for a long time. Growing, the spots ring the branches. Above the affected area, tissue influxes may form. Sick branches usually dry out in late summer.

The development of "burn" contributes to excess moisture under the winter shelter.

To avoid severe damage to roses, the shelter should be removed earlier in the spring. Sick and frosted branches must be cut and burned in a timely manner.

As shown in the photo, in the treatment of this disease of roses, plants should be sprayed with preparations containing copper, as in the fight against rust:

Proper agricultural practices (timely fertilization, loosening and watering) contribute to reducing the harmfulness of the disease. It is necessary to achieve good maturation of wood until the end of the vegetation of plants.

For the winter, plants with already fallen leaves should be covered, if possible, in dry weather, so that increased humidity is not created under the shelter. Before shelter, unripened shoots with green leaves are removed, and the plants are sprayed with a 3% Bordeaux mixture or a 1.5% solution of ferrous sulfate.

Cytosporosis is a fungal disease of roses in the photo

Cytosporosis is a fungal disease that is ubiquitous. Roses are affected by a number of ornamental shrubs, as well as pome and stone fruit trees, nuts.

Cytosporosis is also called infectious desiccation. In some years, it leads not only to the drying of individual branches, but also to the death of plants. This disease bushes weakened as a result of freezing, drought, sunburn, untimely pruning, etc.

First, the causative agent of the disease settles on dying separate sections bark. On the entire area of the affected bark, large, clearly visible orange-red tubercles-pycnidia of the fungus appear, protruding from under the skin.

Look at the photo - with this disease of roses, cracks form on the border of the affected and healthy tissue:

The causative agent of the disease first moves up through the tissues and vessels of plants, and after the branches dry up, down, killing the cells adjacent to the zone of its distribution with its toxins.

The disease of 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.

Also, regularly carry out activities that increase the viability of plants - timely and proper pruning, fertilization, tillage, watering, protection from sunburn, increasing winter hardiness, cutting and burning branches with signs of disease, capturing up to 5 cm of the healthy part of the branch.

Early spring spraying of roses with a 1.5% solution of copper sulfate on "sleeping" buds and 3% Bordeaux liquid along the green cone to some extent restrains the spread and development of the disease.

Trimming bushes in optimal timing protects roses from the appearance of cytosporosis.

Gray rot on roses (photo)

From the gray rot of roses (botrytis), mainly buds with pedicels, the tops of young stems and leaves suffer - in wet weather they are covered with a gray fluffy coating.

First of all, this disease garden roses attacks weakened plants, and most often - with white and light pink flowers. The buds on roses affected by botrytis do not open, rot and fall off. Small brown spots appear on the petals, the leaves turn yellow and also fall off.

Foci of infection persist in plant debris in the form of mycelium, which forms spores in spring. The spores are then dispersed by insects and the wind. Therefore, an undesirable "neighbor" for roses is, for example, garden strawberry, very susceptible to botrytis.

Gray rot appears on roses with dense plantings, or if the rose garden is watered late in the evening, when the rose leaves do not have time to dry before night.

How to deal with gray mold of roses on personal plot? Control and prevention measures for this rose disease are the same as against other fungal diseases.

Interesting facts about rose diseases

Speaking about diseases of roses, we can highlight several interesting facts:

You can determine how resistant roses are to diseases by the leaves: if they are dense and shiny, covered with a wax coating, the variety is resistant. The fact is that wax prevents the penetration of infection into the leaf, which means it prevents infection.
Absolutely disease-resistant varieties do not exist. Even those varieties that are marked “disease-resistant” in the catalogs lose this valuable quality after 5-6 years, as the diseases adapt to changing conditions and mutate like the flu. Therefore, old varieties of roses can only be found in amateur gardens, but not in flower farms and on city streets.
Gray rot, for example, multiplies especially quickly in wet weather, and given that many gardeners plant roses thickly, the soil under the plants does not dry out quickly enough after rain or watering.
Leaves that do not dry out for a long time or cool nights, dew in the morning favor the defeat of black spot. Powdery mildew, and from pests - spider mite On the contrary, they like dry and hot weather. Therefore, roses growing near southern walls or fences are especially affected by these pests.
Flower growers can to some extent influence the development of diseases and the appearance of pests, as well as predict their appearance. Strong, well-groomed plants get sick less often and weaker, more intensively resist pest settlement.

Watch the video "Diseases of Roses", which shows all the main plant diseases and methods of dealing with them:

How to treat roses for diseases: effective remedies

All flower growers, without exception, are interested in how to treat roses from diseases. The most effective remedies for rose diseases include the following drugs.

Alirin-B- a biological preparation based on beneficial microorganisms isolated from natural sources. Effective in the fight against powdery mildew of flower-decorative and other plants.

"Gliocladin"- an analogue of the well-known drug "Trichodermin". Effective against a wide range of fungal diseases such as fusarium, white and gray rot, late blight, root and stem rot, black leg and cabbage club.

"Gamair"- a preparation designed to protect against a wide range of bacterial diseases: bacterial leaf spots, bacterial burn, bacterial cancer.

"Topaz"- a systemic fungicide for the protection of ornamental, pome, stone fruit, berry, vegetable crops and vine from powdery mildew. This preparation for the treatment of roses against diseases can be used as a protective, curative and exterminating agent also against rust. The drug is available as an emulsion concentrate.

As a fighter with a high degree of powdery mildew damage, Topaz is used in elevated concentrations (up to 10 ml), conducting 2 sprays with an interval of 7 days.

The drug provides reliable protection against powdery mildew even against a high infectious background. Topaz is non-phytotoxic and does not leave stains on treated leaves and fruits. As a prophylactic, it reduces the number of treatments, as it works for 40 days. The drug responds modern requirements safety for humans and the environment. It is quickly absorbed by plants, which reduces the risk of washing off the drug by rain.

In order to avoid the appearance of resistance of powdery mildew pathogens, it is recommended to alternate Topaz with contact copper-containing preparations and colloidal gray and not use more than 4 times per season on the same crop.

"Topaz" compatible with most pest and disease control products used in gardens. Speed of influence - in 2-3 hours after spraying.

And how else to treat roses from diseases and to prevent infections in the garden?

"Pure Flower"- a new preparation for the protection of flower and ornamental crops from diseases (fungicide).

Method of application: the required rate of the drug in a special container is dissolved in a small amount of water. Then, with constant stirring, bring the volume of the working solution to 5 or 10 liters. The working fluid is prepared immediately before use and used completely on the same day. The term for the safe exit of people for manual work is after 7 days. Speed of influence of a preparation: in 2 hours after processing.

Protective action period: at preventive treatments- 7-15 days, in conditions of intensive development of diseases - 7 days.

Therapeutic effect of the drug: within 4 days from the moment of infection. Amateur gardeners are not recommended to mix this preparation with other means of protection when spraying plants.

"Pure Flower" is an analogue of the drug "Raek".

"Fundazol"- systemic preparation and protectant planting material to protect against a range of diseases.

When using the drug, fill the container for dressing the planting material with water by 1/3, then pour the required amount of the drug, mix thoroughly and add the remaining amount of water.

Spray the plants with a freshly prepared solution in dry, calm weather, preferably in the morning (before 10 am) or in the evening (6-10 pm), evenly wetting the leaves. The working solution cannot be stored!

"Skor to Protect Roses" from black spot, ornamental and fruit crops from a complex of diseases. It is a systemic fungicide of preventive and curative action. The contents of the ampoule must be diluted in water.

Spray with a freshly prepared solution in dry, calm weather, evenly wetting the plants.

Consumption of working fluid: on a rose - up to 1 liter per plant; on the flower plants and ornamental shrubs- up to 10 liters per 100 m2.

Do not store working solution! Release dates for handmade: 3 days. Compatibility with other pesticides is impractical. The period of protective action is 7-14 days. Exposure time: two hours after treatment. Not phytotoxic. Cultures are tolerant to the drug. There is no resistance. Not dangerous for bees (grade 3). Toxic to fish, do not allow to enter the aquatic environment.

"Copper oxychloride"(wettable powder) - one of the copper-containing drugs to combat diseases of vegetable and fruit crops.

When using the contents of the package (40 g) dilute in 10 liters of water. It is necessary to spray the plants with a freshly prepared solution in dry, calm weather, preferably in the morning (before 10 o'clock) or in the evening (18-22 o'clock), evenly wetting the leaves. In the recommended doses, the drug is not phytotoxic. The period of protective action is 7-10 days.

The drug is dangerous for bees and fish, do not treat during flowering. Do not allow to enter watercourses.

These photos show effective means for the treatment of diseases of roses:

How to spray roses for diseases: the best drugs

Not sure how to spray roses for diseases to protect flowers? Then use the following drugs, which are considered among the best.

"Abiga Peak" is a copper-containing fungicide of contact action, designed to combat a complex of fungal and bacterial diseases on vegetable, fruit, ornamental and flower crops, vine and medicinal plants.

Apply the drug during the growing season by spraying plants.

The 50 g package is designed to prepare 10 liters of working solution for the treatment of 100 m2.

The contents of the vial are preliminarily dissolved in 1 l of water and, with thorough mixing, brought to 10 l with water - a working solution for spraying is obtained.

Spraying is carried out prophylactically or when the first signs of the disease appear. Plants are processed, evenly covering shoots, leaves and fruits with a working solution.

Attention! All solutions should be prepared in plastic, glass or enamelware.

This preparation against diseases of roses provides reliable protection of plants from diseases even under adverse weather conditions. The composition of the drug includes an adhesive that allows the active substance "Abiga-Peak" to be firmly held on the treated plant surface.

Very important!"Abiga-Peak" is compatible with almost all known modern insecticides and fungicides. Easy to use, non-toxic. The drug does not produce dust when preparing a working solution. Cooked but due weather conditions unused solution can be stored for a long time.

"Abiga Peak" beneficial effect on the quality of the products grown. With its application, a good maturation of young shoots is observed.

The best means to combat rose diseases are shown in the photo:

"Thiovit Jet"- a means to combat diseases of flower and fruit crops.

How to use: dissolve the norm of the drug in a small amount of water, then, gradually stirring, add water up to 10 liters. Processing should be carried out with a freshly prepared solution in dry, calm weather, ensuring uniform wetting of the leaves.

"Thiovit" has good adhesion, has a contact effect and an active gas phase; practically non-toxic to birds, bees, fish.

The advantages of the drug are that it is both a fungicide, an acaricide, and a trace element; provides reliable plant protection for 7-10 days; can be used for preventive spraying, has good compatibility with other pesticides.

"Sulfur colloidal" It is mainly used to control powdery mildew and various types of herbivorous mites on flower crops. It shows efficiency only at air temperatures above +20 ... + 22 ° С, since sulfur vapors work.

Mode of application. When preparing the working fluid, the preparation is first stirred in a small amount warm water to a creamy state, and then water is added, mixing the composition well (it is better to soak the drug the day before, 2-5 hours before processing).

The term of the last treatment before harvesting is 3 days.

For humans and warm-blooded animals, the drug is not dangerous. "Sulfur colloidal", as a rule, does not burn the leaves.

However, many varieties of gooseberries shed their leaves after processing. Therefore, do not use sulfur to control American gooseberry powdery mildew and do not spray roses near this shrub.

Remember! Before treating rose diseases, you must carefully read the instructions for using a particular drug.

Red dots on rose petals. Disease or feature? That's for sure - live a century - learn a century! I admire my roses, once again, and notice red freckles on them. I thought they were over-pollinated, but no! I came across an article that opened my eyes to this feature of roses. It turns out that this is how the rose reacts to stress. Further I will not be clever, I publish the material in its entirety.

Question one: who is to blame? First, you need to make a reservation: we are talking about red dots, and not about large spots. These dots are round in shape and, as a rule, do not exceed 5 mm in diameter. The appearance of a "red rash" on rose petals is most likely protective. This, apparently, is a kind of protective barrier produced by the rose in response to damage to petal cells of various origins. This barrier separates the affected tissue from healthy tissue, preventing the spread of the lesion: the cells inside the annular red barrier die, while the outside remains intact. In other words, the scheme is approximately as follows: 1) cell damage - 2) formation of an anthocyanin barrier around it - 3) activation of enzymes inside the barrier - tissue compaction along its outer side - 4) formation of phenolic compounds directed inside the barrier - 5) cell death inside barrier. Thus, red dots on flowers do not indicate a disease of the whole plant. This is a local phenomenon, signaling some damage to these flower cells. Infectious diseases caused by necrophyte fungi (botrytis, for example) can enter cells through areas that have died on the petals, but they themselves do not produce red pigment. In other words, red dots are not a sign of botrytis or any other infectious disease, however, on the affected tissue of the petal inside such a “point” when certain conditions certain diseases may develop.

Red dots on flowers most often appear: 1) when the flower ages; 2) when the cells of the petals are damaged by cold rain, dew; 3) when the cells of the petals are damaged by insects. At favorable conditions and good condition plants dot may not appear, the flowers remain clean. Even aging flowers may not be covered with red dots if the conditions are quite favorable and the plant itself is strong enough. On the other hand, the same plant tissues can suffer simultaneously from several causes. For example, from malnutrition, from insect damage and from infection, or even from several infections at once. In this case, the anthocyanin barrier may still appear: this is a non-specific reaction of flower cells to any damage. Important in the appearance of red dots on roses are, in addition to those listed external conditions, characteristics of the variety. Not all varieties of even light-colored roses react to stress and damage by developing a bright anthocyanin barrier. Some varieties do not have this ability, although this does not mean that these roses do not resist pathogens. It's just that the immune system of such roses reacts differently.

Most prone to the appearance of red dots are roses with light-colored petals (white, pink, yellow). Among these roses, varieties were noted that more often than others can react to cellular damage with a red "rash". Here is a partial list of these varieties, based on data received from the participants in the discussion. Alaska .Bordure Сamaeu 16.Bradford 17.Candelight 18.Casteau Gombert 19.Charles Darwin 20.Cherry Brandy 21.Chopin 22.Christopher Marlowe 23.Claire Austin 24.Claire Renaissance 25.Claudia Cardinale 26.Dancing Girl 27.Decor Arlequin 28. Evelyne Dheliat 29.Folklore 30.Fortuna 31.Gloria Dei 32.Golden Border 33.Golden Celebration 34.Golden Medallion 35.Golden Silk 36.Graham Thomas 37.Hans Gonewein Rose 38.Heritage 39.Irene Frain 40.Karen Blixen 41. Kent 42.Kerio 43.Jardins de France 44.Jeanne Moreau 45.Laminuette 46.Lavender Pinocchio 47.Lawinia 48.Lions Rose 49.Love Song 50.Marilyn Monroe 51.Marjorie Marshall 52.Molineux 53.Nemo 54.Octavia Hill 55 .Osiana 56.Perdita 57.Pierre Dittiere 58.Poustinia 59.Prestige de Lyon 60.Ramira 61.Rene Goscinny 62.Rokoko 63.Samaritan 64.Schneewittchen 65.Spanish Dancer 6 6.The Wainwright Rose 67.Well Being 68.Wollerton Old Hall 69.Winchester Cathedral Naturally, this list is indicative: the degree of manifestation of red dots was estimated very subjectively and approximately. This degree depends on the variety of the rose, and on the scale and nature of the damage, and on the resistance of the plant itself.

And yet, to the question: “Who is to blame?” - we can generally answer. The reasons for the appearance of red dots may be the following: 1) the tendency of the variety (mandatory factor); 2) flower aging; 3) violation of the temperature and humidity regime (sudden temperature changes, cold rains and dews, heavy cold rains, drought); 4) mechanical damage to the petals (due to a sharp wind, for example, as well as damage by insects); 5) sun or chemical burns; 6) weakening of the plant (with a lack or excess of phosphorus and potassium; with an excess of nitrogen; with a lack of trace elements; with weed infestation, etc.). It is clear that the aging of the flower is impossible to resist. But is it possible to prevent the appearance of red dots in other cases?

Question two: what to do? The first thing that can be said in response to this question is not to try to "treat" flowering bushes. Especially with chemicals. (In general, it seems to me that it would be possible to use chemical agents if we had a laboratory at hand. I conducted an analysis - and based on its results, I decided on the right amount any chemical agent. And even then, probably, it would not be worth abusing it.) Since red dots are not a disease, there is simply nothing to treat here. You can try to prevent the appearance of red dots by the following methods: 1) from opening to hiding roses, take care of strengthening the immunity of plants (using "Zircon" and other biological agents); 2) in necessary cases, correctly use anti-stress drugs (Epin, Zircon, Mival-Agro, etc.); 3) strengthen plant tissues (use silicon-containing products, establish regular and proper watering etc.); 4) protect roses from damage by insects (especially sucking ones); 5) try to protect roses from possible winds (for example, using rocker landings); 6) strive to improve proper nutrition roses in the specific conditions of your garden. In other words, develop for yourself the right strategy for agrotechnical and protective measures in relation to the available conditions and varieties. And this means constantly carefully observing the plants, thinking, comparing and trying to understand your garden and its possible problems. Author: Isstep

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