Brown spots on a rose. How to treat black spots on rose leaves

Often weakened or improperly planted plants suffer. In addition, neglect of care will inevitably lead to the occurrence of diseases and developmental problems.

For good growth, beautiful flowering roses need constant attention from the gardener. Preventive checkups, the ability to immediately identify the first alarming signs make it possible to quickly prevent almost any ailment.

Quite often, the "queen of the flower garden" is sick due to:

• weather conditions (for example, high humidity or prolonged heat);
• poor lighting, insufficient air supply;
• tightness in the rose garden;
• mechanical damage to stems, root neck.

The greatest damage is caused by infectious diseases, the causative agents of which are fungi, viruses, and bacteria. But there are also functional diseases: they appear when there is a lack of any element in the soil.

What is wrong with roses?

powdery mildew

In summer, powdery spots of a whitish-gray bloom are often found on roses, which later acquire a grayish-brown color. Buds and shoots die off, leaves curl. This is how it manifests powdery mildew: her activator - Sphaerotheca pannosa. The fungus overwinters on stems and plant debris. The appearance of a raid - sure sign that the flower is overfed nitrogen fertilizers but is deficient in potassium.

In addition, it is not recommended to carry out sprinkling irrigation in the evening: such procedures are more useful in the morning or afternoon. Bushes planted in a dense pattern, and even in a poorly lit place, are more susceptible to attack by pathogens. Powdery mildew is easier to prevent, because then you have to fight it for several seasons.

So what to do:

1. for the purpose of prevention, the rose garden, including the ground around, is pollinated with ash, and also sprayed once a week with mullein infusion in the usual proportion of 1:10;
2. affected branches, buds are cut to a healthy place and burned. Three times every ten days, plantings and soil are treated with Bordeaux liquid (usually 1%);
3. from systemic fungicides suitable for spraying Topaz, Skor, Vectra.

Gray rot

fungus spores Botrytis cinerea suppress the growth point of young shoots, affect the buds and buds, which rot without even opening. On the petals you can see characteristic brown sores, the leaves turn yellow. Wet weather promotes the development of a gray fluffy coating on the stems.

The fungus is activated with dense plantings, high humidity, and also due to a lack of potassium and phosphorus in the soil. Gray rot strongly affects multi-petal varieties, mainly white, cream, yellow.

What to do:

1. a pink solution of potassium permanganate is the best preventive measure: you can spray or water the bushes with it;
2. cut out infected parts and remove from the site;
3. try to create the maximum possible dryness in the rose garden, feed with phosphorus and calcium 2: 1;
4. effective spraying with drugs Vectra, Fundazol, iron vitriol.

black spot

fungus infection Marssonina rosae occurs in late spring, and the first symptoms appear only closer to August. Brown or black spots form on the leaves, they quickly increase, growing over the surface. A weakened bush sheds foliage, blooms very poorly. Black spot begins to progress when high humidity.

It is quite difficult to get rid of the disease, since the fungus is perfectly preserved on fallen leaves. Therefore, intensive spring pruning, cleaning last year's plant residues and mulching are extraordinary treatments. By the way, yellow varieties are more prone to black spotting.

Fighting methods:

1. be sure to cut off diseased leaves;
2. in sunny weather, the bushes are poured with a soda solution (half a glass for 3.5 liters of clean water);
3. next folk way- dilute a glass of milk in 12 liters of water and give the "injured" a shower;
4. planting processing Tsineb, Benlat, Topaz, Fast, Fundazol. Bordeaux liquid also can help, as well as copper sulfate.

Rust

A particularly strong rust fungus of the genus Phragmidium repairers are affected, park varieties, wild roses. In spring, bright red pustules with spores appear on the root neck, shoots, at the bottom of the leaf blade. Since July, they turn black, the foliage falls off, the shoots are deformed and dry. Rust is very difficult to deal with, especially in rainy summers. If the rose is badly damaged, it cannot be treated: such specimens are destroyed.

Treatment methods:

1. do for prevention foliar top dressing extract of superphosphate (0.3%), potassium nitrate (0.3%);
2. the affected parts must be cut out, the fallen residues raked up and burned. After each trimming, the tool is processed in denatured alcohol;
3. plantings, the ground around is sprayed with copper-containing preparations, as well as Topaz, Profit.
   

Viral mosaic

Characteristic signs of viral mosaic - appearance on leaf blades yellow streaks. In addition to the marble pattern, the leaves often become wrinkled, very narrow, curly. Plants weaken, their growth slows down, they quickly die. Aphids, mites, and rose grafting are often the cause of the spread of viral mosaics.

The disease is easily transmitted through tools, hands, gloves. Sick specimens are not used for reproduction. Some gardeners are in no hurry to dig up diseased bushes, if they are still quite strong: they are fed with fertilizers with a full composition of trace elements. Plants that are too affected are, of course, destroyed.

Agree, having a beautiful and healthy flower garden in your garden is very pleasant. It is especially pleasant when the queens of flowers are fragrant in the garden all summer long. But, unfortunately, this joy can quickly be overshadowed by various fungi, viruses and pests. A common disease of roses is black spotting, when black spots appear on the leaves of roses and you need to know how to treat them. In this article, you will learn how to solve this problem and what methods help get rid of the disease.

Unfortunately, black spot on roses is considered almost the most dangerous disease, which is not so easy to get rid of, in some cases even the best preparations may be useless.

First of all, black spot affects diseased and young shoots. Spring auspicious time for the development of the fungus, since at this time the humidity is high. If the infection occurred in the spring, then the signs of the disease can not be seen immediately, at least after a month.

If the weather is warmer (up to 30C), then the fungus develops rapidly and after 10 days you can see the first signs. The fungus does not like dry and hot weather, therefore, dies at a temperature of 35C.

Black spot can also occur in roses due to lack of nutrition, especially if the plant lacks potassium.

Favorable conditions for the development of black spot

• Insufficiently lit place;
• Heavy, clay soil;
• Weeds (need to be removed regularly);
• Dense planting bushes;
• Nutrient deficiencies;
• Excessive watering;
• Incorrect pruning (use of dirty, unfinished tools;
• Adverse weather(rain, damp).

black spot symptoms

As I wrote above, the first signs of the disease do not appear immediately. You can only find out that the plant is sick in the second half of summer. But when the first signs appear, the disease spreads very quickly.

First, dark brown spots with yellow edges appear on the leaves of roses. Gradually, the leaves turn yellow and die. They also appear on stems. dark spots. Flowering stops. As a result, the rose stops growing, loses foliage and takes on an ugly appearance.

Unfortunately, black spots on roses are treated with great difficulty, sometimes any action can be in vain. Therefore, it is easier to prevent the disease than to treat it.

"The best fight against black spot on roses is prevention"

The treatment of black spots on roses must begin, as they say in advance, before planting the rose in open ground and even before buying it. Therefore, we will start with the purchase of roses.

1. You need to buy roses only in a special store, or a horticultural farm, where the likelihood of a disease can be equated to zero.
2. Choose varieties that minimize the risk of spotting. Fortunately, most modern varieties have this feature.
3. After buying a rose, choose for planting suitable site so that everything matches the requests of the flower queen.
4. Do not plant a rose in places where roses grew less than 5 years ago, or other plants that suffer from the same diseases as the rose.
5. Try to follow the rules of care correctly, based on the plant variety.
6. Be sure to inspect the plant regularly for suspicious symptoms. This will help you to early dates identify the disease and take appropriate measures immediately.

If you regularly inspect the plant for diseases, then the disease can be detected in the early stages, before it spreads and infects the entire plant. If you notice the first signs of the disease, then be sure to remove all damaged parts (leaves, shoots, flowers), without sparing.

1. On the initial stages the plant can be sprayed with horsetail infusion (pour 1 kg of fresh grass, or 150 grams of dry bucket of water and leave for a day, then boil the infusion for 30 minutes, let it cool and strain. Dilute the infusion with water 1:10).
2. Spray the rose with sulfur-containing preparations every 10 days.
3. It is also recommended to spray roses with preparations containing copper (at any time of the year copper - soapy water, and in autumn 5% blue vitriol).
4. If no measures helped, then they resort to at least - we treat the plant with Bordeaux liquid every 7 to 10 days. Pour the soil around the bush with the same solution. This drug is highly toxic to both humans and environment Therefore, we are taking all precautions.

“For the purpose of prevention, it is possible to introduce fungicides into it while loosening the soil”

You can also buy other drugs in a specialized store that contain substances such as triazole and mancozeb. The first seven days, roses are treated with preparations containing mincozeb, and a week later they are treated with preparations containing triazole.

It is necessary to process plants in dry weather so that there is no dew on the leaves. Before processing, the plant must be watered and sprayed with a solution.

When the black spots from the plant disappear, still be vigilant and inspect the plant more carefully and more often than before the disease. With repeated signs, diseased leaves are removed and burned, and the rose is again treated with drugs.

Well, now you know why black spots appear on rose leaves, what to do about it and how to treat the plant. I also told why roses suffer from black spot, what control measures exist, what preparations can be used for processing. I hope these recommendations were useful to you and you found answers to your questions.

I will be glad to your responses and comments. If you tell me about your experience, how you treat your plants, I will be very grateful.

Black spot is a very common disease on rose leaves. This is a problem for all rose lovers. This is fungal disease and all varieties of roses are subject to it to varying degrees. The leaves of the plant affected by the disease are covered with dark stains similar to spots.

How does black spot appear on a rose

Most often, the disease manifests itself by mid-summer, but can begin to progress as early as June. Like all fungi, it reproduces by spores that appear from spots formed on the leaves. At first, it can be seen on young leaves and shoots. If the disease is allowed to progress, then it will cover not only the entire bush, but also neighboring plants. This will greatly worsen the condition of a previously healthy bush, weaken and possibly destroy it.

Provokes disease high humidity and fluctuations in day and night temperatures.

It is necessary to be vigilant at the first manifestations of the attack of the fungus. And get treated right away.

Marssonina rosae is the name of the causative agent of the disease. He feels good in humid environment, in a densely planted rose garden. Its spores spread very quickly. During the season, if the plants are not treated, then several outbreaks are possible, which will lead to the murder of your magnificence.

Treatment of roses from black spot

As a fight against a problem that has already appeared, it is recommended to treat the bushes with fungicides from the spring. These are zinc-based products. Processing is carried out twice with an interval of 14 days. Also, Topaz, Ridomil Gold have proven themselves well. They can be used as a preventive measure for diseases of seedlings.

If the weather conditions are not on your side and rainy weather has set in, the treatment should be carried out with colloidal sulfur preparations (40 grams per 5 liter of water), as well as Fundazop or Saprol.

These drugs work every 10 days until the spread of the fungus completely stops. In the spring, even before bud break, a 3% solution of ferrous sulfate can be used.

Bordeaux mixture is good for widespread infection of the rose garden. It is processed once a week. But use it with great care and in extreme cases, because its impact on everything around is extremely negative.

It is possible to use improvised means. Infusions and decoctions of nettle and horsetail will help protect your rose garden from many diseases and pests during the period of set color and flowering itself.

Prevention measures

In autumn, all infected leaves and stems of the plant are removed and the soil around them is carefully loosened. As the soil loosens, the spores will rise to the surface and die over the winter.

A preventive measure is also spraying the bushes with a 3% solution of copper sulphate or the Hom preparation (40 grams per 10 liter of water using per 100 sq.m.). This is recommended to be done both before sheltering the bushes for the winter, and with early manifestations of infection.

Many of these problems can be avoided by buying planting material only from trusted manufacturers. It is recommended to purchase varieties resistant to diseases and pests. Many hybrid tea varieties, Floribunda roses are popular. The work of breeders pleases us with many resistant species, not only to black spot, these are varieties: Quadra, Resonance, Leonardo da Vinci.

For a reasonable attitude to fertilizers used for the growth and flowering of buds, as well as chemicals, your rose garden will more than thank you. For more than one season, it will delight you and surprise you with the beauty and magnificence of shapes and colors.

Handsome and blooming garden is not only planting cultivated plants, but also daily care followed by. Of course, the "queen of flowers" rose will become a unique decoration of any garden. Have you noticed black spots on rose leaves? At the same time, you don’t know what to do with the plant and how to treat the leaves? Then this article is for you!

The effectiveness of the fight against any disease depends on the correct definition of the disease and finding out the causes. The black spot of roses is easily identified by its characteristic features:

• the bush stops growing and does not throw out new buds;
• dark spots form on the lower leaves of the plant, which visually resemble the sun in their shape;
• the diameter of the spots can be from 5 to 15 mm;
• the brownish tone of the middle with a yellow edging gradually acquires a darker color;
• small black spots on roses eventually combine into one large one, affecting the entire leaf, as a result of which the leaf turns yellow, dries up and falls off;
• disease moves from bottom to top.

The disease progresses especially in the second half of summer. During one growing season, several active outbreaks are possible. Climbing and rose varieties are at risk.

In addition to defining the disease (black spot of roses is often confused with), it is important to establish the causes that could affect the onset and development of the disease. So, the key reasons are:

• improperly selected place for planting a seedling (poor air circulation, lack of sun, as well as a large number of plants prevent the evaporation of moisture, which contributes to the development of the fungus);
• weather and climatic conditions (an abundance of precipitation, after which the dry season begins - an excellent environment for the reproduction of spores of fungal infections);
• improperly organized top dressing (both lack and excess of fertilizers);
• lack of proper care for ornamental culture.

What is the danger to the plant

Black spot on roses is a dangerous disease. As you know, any disease is much easier to prevent than to deal with it later. possible consequences But, as they say, everything happens in life. They did not carry out timely prevention of diseases of ornamental culture or did not pay attention to black and brown spots on the lower leaves - now you have to deal with what is already there.

Remember that the disease itself will not disappear. If you do not take emergency measures for treatment, then first the rose will shed the lower leaves, which already have dark spots, then all the remaining foliage will crumble. The disease gradually covers the entire plant, after one or two seasons the rose will die.

Black spot is a fungal disease of Marssonina rosae that is spread by dewdrops or rain. Having found dark marks on the leaves of one ornamental crop and without taking any methods to combat the disease, one should not be surprised when, after a while, you will see similar symptoms on other plants of yours.

Prevention and treatment

Have you noticed black spotting of roses in your garden, but do not know how to deal with it? It will be difficult to cure the plant if the disease is running. But do not despair and give up - you can still fix it if you properly treat the affected areas and take preventive measures in relation to other rose bushes.

Unfortunately, most of novice gardeners make an irreparable mistake in caring for their rosary: ​​noticing that leaves with black spots fall off on their own, they let the situation take its course, hoping that the ailment will pass during the winter without their intervention. The spores of the fungus overwinter in the soil and become active with the onset of spring.

What should be done when the first signs of black spot are found? Inspect the plant carefully, cut off all leaves affected by the fungus and burn them in a remote area of ​​\u200b\u200bthe garden or even outside its territory. The next step - roses are treated with fungicides, which contain mancozeb and zinc. This procedure should be repeated every 2 weeks. To avoid addiction of the fungus to the drug, alternate different chemicals. The most common and potent include: "Oxyhom", "Profit", "Fundazol", "Topaz", "Skor", "Strobi", "Ridomil Gold", copper oxychloride and others.

If there is no desire to use chemicals, then you can try to use biologically active drugs, among which Fitosporin-M is considered the most effective.

In the fight against black spot, all means are good, so we suggest that you put into practice some folk methods:

• infusion of horsetail, dandelion and nettle;
• a decoction of onion and garlic peels;
• sprinkling of the affected areas with crushed ash;
• cow dung, previously diluted in water in a ratio of 1:10;
• decoction or infusion of citrus peel.

For greater effectiveness in the struggle for a plant, you can combine folk methods with professional means.

Video "Black spotting of roses"

From this video you will learn how to deal with black spot on rose leaves.

12 Apr 2013

The beauty of flowers, first of all, depends on the health of the plant, and even the queen of the garden - a rose damaged by disease, loses its royal appearance. That is why flower growers need to constantly monitor the condition of the grown flowers, as well as constantly replenish their knowledge of identifying signs of diseases, pest and disease control measures.

powdery mildew - dangerous disease that affects roses caused by a fungus. Initially covers buds, young shoots and leaves, which can be detected by the appearance white plaque, which eventually becomes gray with black dots - these are the fruiting bodies of the fungus. Affected buds and leaves soon turn brown and dry out, the shoots become deformed and stop growing. A diseased rose bush stops blooming, sheds almost all the leaves and lags behind in development. Roses with a matte surface of the leaves are most susceptible to powdery mildew, roses with glossy leaves get sick less often and resist the disease more.

The spores of the fungus are easily carried by the wind to neighboring plants, increasing the area of ​​powdery rose infestation. Powdery mildew often appears in the second half of summer, closer to autumn. The development of the disease is facilitated by sharp changes in day and night temperatures with dew, high humidity, thickened plantings and excess nitrogen fertilizers.

To prevent the spread of the disease, cut off all affected leaves, buds, shoots that need to be burned. At the first signs of the disease, start periodic spraying after 7-10 days with one of the drugs: Topaz, Skor or Colloidal Sulfur (40g per 5 liters of water). Since the spores of the fungus persist and overwinter on plant debris, carefully collect all the fallen leaves, debris and burn them in the fall, dig up the ground around the bushes.

Rust- also a fungal disease that appears in the summer on the underside of the leaves. At first, yellow spots are noticeable on the wrong side of the sheet, which soon grow, become convex and acquire Orange color rust. Affected leaves dry out prematurely and fall off. The shoots at the base thicken, crack, and rust is also visible in the cracks. Varieties are more susceptible to this disease. park roses, hybrid tea, polyanthus and climbing roses proved to be more resistant to rust.

To prevent the appearance of the disease the following year, in the fall, all plant residues are carefully collected and burned. Before shelter for the winter and spring, before bud break, preventive spraying of rose bushes is carried out with any of the preparations: “Hom”, copper sulphate or Bordeaux liquid.

Leaf spots. The appearance of spots on the leaves of roses of any shape and color should alert the grower. These spots mean dead areas of the leaf - necrosis caused by fungi pathogens inside the leaf. Often spots appear already on matured leaves. With a massive spread of the disease, the leaves fall prematurely, the rose bush loses its decorative effect, flowering weakens, the plant as a whole lags behind in development and is not gaining strength for wintering.

Peronosporosis or downy mildewappears on the leaves in the form of dark brown spots, on the underside of the leaf you can see a small bluish bloom. The leaves begin to fall off prematurely, and with a strong infection, young shoots can also be affected.

black spotAlso known as "marsonine of roses". The causative agent of the disease is a fungus that affects still young shoots, the leaves are covered with large brown spots, gradually expanding. Soon the affected leaves fall off.

Phyllostic blotch appears on the leaves as small brown spots with a light center.

Septoria spotting can be seen on the leaves by numerous round spots bordered by a brown stripe.

Ascochitous spotting is determined by small irregular shape yellow spots on leaves. Infected leaves turn yellow and fall off.

Purple spot appears on the leaves as small red-brown spots.

You may not be able to distinguish between varieties of rose leaf spot, as the control measures for these diseases are the same. Affected areas and leaves are cut and burned. Rose bushes are sprayed in the spring with bud break and before each flowering with any of the preparations: Bordeaux liquid, Hom, Vectra. In the fall, be sure to do a sanitary cleaning of fallen leaves and debris, since it is on plant residues that spores, pathogens of fungal diseases, hibernate.

The most dangerousrose diseases are rot. Root or fusarium rotcauses rotting of the roots, gradually covering the entire plant as a whole. The causative agents of the fungus penetrate from the soil into the roots and spread through the vascular system throughout the plant. Brown spots appear on the leaves, spreading from the petiole along the veins. The plant first weakens, the leaves gradually dry up, the young shoots wither, the rose soon dies, and it is impossible to save the bush. The infection of the disease persists in all parts of the plant, so even cuttings cannot be taken from it.

Gray rotcauses rotting and death of stems with leaves and buds. The causative agent of the disease, the fungus develops in the ground even in the cold season. In the spring, after removing the shelter, when browned rotten shoots with a fluffy coating are found, this is most likely caused by the development of gray rot. In summer, gray rot often occurs with high humidity, the plant appears gray coating and brown spots.

The fight against diseases - rot, of an already infected plant, is often already lost, so all measures are reduced to prevention. Buy only healthy proven rose seedlings. In autumn, be sure to do sanitary cleaning of plant residues by burning them. Remove diseased plants along with the roots and burn. Shoot in time winter shelter with roses. Against Fusarium rot, spray and water under the root with the fungicidal preparation "Fundazol". To combat gray rot, cut out the affected shoots in time and spray the bushes with a solution of iron sulfate.

Stem necrosis.The appearance of dark brown, almost black spots on the stems is caused by the death of the bark, which leads to the drying of the stem. Such lesions, necrosis are calledinfectious burn or stem cancer. Typical signs the appearance of the disease, reddish-brown spots encircling the stem with the further appearance of cracks and sores. Infection - spores persist in the bark of infected stems, so rose bushes should be pruned in a timely manner, removing dried branches. Preventive spraying of rose bushes with Bordeaux liquid is carried out in the spring before the leaves bloom.

Of course, it's not always a loss. flowering species roses is caused by diseases, this can also happen due tolack of essential micronutrients in the soil, as the leaves of the plant tell. So, with a lack of nitrogen, roses grow slowly, new leaves appear small, light yellow color are sometimes stained. With a lack of phosphorus, young leaves also become smaller, and from the inside they dark purple. The appearance of brown dried areas along the edge of the leaves means a lack of potassium. With a lack of magnesium, the central part of the leaves turns yellow. Iron deficiency in the soil causes chlorosis - yellowing of the leaves. With a lack of manganese, the leaves become striped, the areas along the veins of the leaf remain green.