The phlox diseases presented here often lead to the fact that the long-awaited flowering never occurs. Knowing everything about phlox diseases and their treatment is very important, as timely measures taken to protect the flower garden create conditions for lush and long-term flowering.
On this page, phlox disease with photos will allow you to carefully study them and become familiar with the methods of color protection.
But it is worth remembering that the use of chemicals in practice is not always justified. Especially if plantings of vegetables and berry crops are located next to the flower garden. So look phlox disease with photos and their treatment, but always choose the safest ways to fight. The most dangerous fungal diseases of phlox are perennial, since they quickly spread under the unfavorable environmental conditions around the household plot.
Further fungal diseases of phlox in the photo are illustrated in all the beauty of their symptoms.
Look carefully at the signs of viral phlox diseases in the photo and measures to combat them, and if the slightest suspicion of their presence in your area appears, immediately take emergency measures of protection.
How to treat phlox from diseases in the spring
Studying phlox diseases and combating them, it is worth noting that they are affected by various pathogens that suppress their vital processes. Under the action of pathogens, physiological and structural changes can be observed in plants, as a result of which the decorative effect of phloxes decreases and biological aging of plants is accelerated. With a strong infection, phlox die. You need to know about how to treat phlox from diseases so that even the slightest sign of infection during the whole summer is noticed.
Disruption of physiological processes is manifested in the weakening of photosynthesis, the disruption of the intensity of respiratory processes, the disruption of transportation of water and nutrients in the plant, as well as the products of photosynthesis, the disruption of the synthesis of growth and storage substances. Structural disorders include deformation of leaves, shoots and flowers. Necrotization of infected cells may be observed.
There are various methods of diagnosing diseases. The simplest available to both professionals and amateur growers is visual.
The nature of the symptoms of plant disease, mainly due to the appearance of lighter or darker areas on the leaves. Usually, pale green or yellowish spots, strips of different length appear along the veins of the leaf; black, brown or brown-red spots of various configurations, as well as rings, strokes, grouped together or randomly scattered throughout the leaf plate. Strokes can be arranged in chains along the veins or at an angle to the center.
With a strong lesion leaves die off, plants are oppressed, the number and size of flowers decreases. Very often phlox are affected not by one disease, but by several at once. Such a complex infection creates some difficulty in identifying the nature of the infection.
The mechanism of propagation of the pathogen is diverse. Its penetration into the plant can also occur in various ways. Transmission occurs at all stages of cultivation. Further on the page, several options have been proposed for how to treat phloxes in the spring from diseases, from which one can choose the most effective and safe means.
The main reservoir of disease are wild (weedy) plants. In this respect, perennial weeds are especially dangerous in this respect, which ensure the continuous spread of numerous infections from year to year. In addition, weeds overwinter and undergo some stages of their development - insects - carriers of infections, therefore it is important to constantly remove weeds. As a rule, diseased phloxes also become foci of infection.
Diseases of perennial phlox and their treatment (with photo)
Sometimes phloxes have longitudinal cracking of the stems. This is not an infectious disease. There may be several reasons - too much acidic soil, sudden drops in day and night temperatures, watering the plants with cold water in hot weather, and also applying only nitrogen fertilizers in the spring.
In some cases, the cracking of phlox stems may be a characteristic feature of the variety, for example, in the variety 'Maria Fedorovna', the cracking of the lower part of the stem is observed more often than in other varieties.
Very often, when cracks form, stem tissue is exposed, while phloxes break. The cracking of the stems on old, too thickened nozzles was also noticed.
Drying of the leaves at the bottom of the stem may also not always be the cause of the infectious disease. This is usually due to a lack of moisture in the soil, with the lower leaves first drooping, then turning yellow and drying out. But we will continue to study the diseases of perennial phlox and their treatment with the help of effective modern means.
With good phlox treatment not required because they get sick much less often. To reduce the risk of phlox infection by diseases, complex protective measures are carried out. It is necessary to comply with agricultural practices (weed and pest control, regular watering, fertilizing and sanitary treatment). It is important to ensure that phloxes do not grow in the same place for many years in a row, as microorganisms accumulate in the soil, which can cause the death of plants. To reduce the intensity of the spread of diseases of great importance is the spacious planting and the absence of phlox monoculture. Of great preventive importance is the hygiene of the site.
It should be remembered that the introduction of phosphate and potash fertilizers increases the resistance of phloxes to diseases, and an excess of nitrogen makes them more susceptible to them.
In most cases, phlox diseases are caused by plant parasites, as well as unfavorable soil and climatic conditions. Most dangerous are viral and mycoplasmal diseases that manifest themselves in different ways. Fungal diseases are also harmful.
Look at the photo of phlox disease and their treatment with simple and affordable tools that are available to each grower:
Proper planting and care - the best protection of perennial phlox against disease (with photo)
In the plant viruses penetrate the damaged integumentary tissue. If the outer shell of plant cells is not damaged, viruses cannot penetrate into the plant's body. Therefore, proper care of phloxemone excludes diseases of viral etiology.
For example, the transmission of a viral infection from a diseased plant to a healthy one can be carried out with mechanical tissue damage (water, wind, contact of plants) and insect vectors. More than 150 insect species that can spread viruses are known, and sometimes, before they enter a new plant, the virus passes a certain developmental cycle inherent in this type of virus. In this case, an infected insect can be a source of infection for a long time.
The main active carriers of viruses are sucking arthropods (various types of aphids, cyclops, herbivorous mites), feeding on sick and healthy plants.
Viruses can also be transmitted by thrips, bedbugs, nematodes, mollusks, wireworms, mice, moles, as well as pathogenic fungi. Infection with a viral infection can occur during vegetative reproduction phlox (through rhizomes and cuttings), it does not matter if you are working with your hands or using an instrument.
Getting into the cell of the host plant, viruses, as a rule, cause a decrease in the intensity of photosynthesis. Under the influence of a viral infection, changes in the water balance, physicochemical properties of plants and metabolism occur. Symptoms of viral diseases are very diverse and can vary depending on temperature, humidity, time of year and other conditions. By the nature of their manifestation they are divided into several types: growth retardation, discoloration, organ deformation, necrosis, and tissue death.
The most characteristic external symptoms of viral diseases on plants are:
Mosaic on the leaves
Lightening leaf tissue along the vein
Ring, spot and mottled spots
Chlorosis of leaf and shoot tissues
Changing the shape and size of leaf blades, flowers, growth retardation
Excessive thickening of the shoots and their cracking
Sprouts and flower color changes
Sometimes diseases are accompanied by shortening of internodes.
Look at the photo planting perennial phlox and care for them in diseases of viral etiology - so you can exclude the spread of infection:
In some cases, plants infected with a virus do not show symptoms of the disease. Such an infection is called latent or latent. It becomes noticeable only when the plant is in adverse conditions. Sometimes on the same plant can be observed the simultaneous manifestation of several viral diseases with different symptoms, however, it happens that a variety of diseases cause similar manifestations in plants. The roots of diseased plants are often necrotic.
Viruses that need a biological method of propagation are able to survive only in living plants or in the body of a insect carrier. Mechanically spreading viruses also prefer to persist in the living parts of plants, but some viruses may not lose their viability even in plant debris.
According to observations, the most common and harmful viral diseases affecting phlox include:
- Tobacco rattle virus,
- alfalfa mosaic virus,
- Cucumber mosaic virus,
- Arabis mosaic virus,
- phlox vein necrosis virus (Phlox necrosis vien virus),
- tobacco necrosis virus (Tobacco necrosis virus),
- Tomato ringsport virus, Tomato ringsport virus,
- Tomato black ring virus (Tomato black ring virus).
No measures to combat viral diseases. Patients phlox are a constant source of infection, they can not be taken vegetative material for reproduction.
Infected plants never recover and serve as a source of infection for other plants, so the affected phlox should be removed and destroyed immediately. If not the whole plant is affected, it is possible, as a temporary measure, to use the technique of cutting the affected shoots. It is very important to use only healthy planting material in a timely manner to sanitize areas.
Viruses can significantly increase the susceptibility of plants to other diseases, such as fungi.
Treatment of phlox in the spring of mycoplasma diseases and powdery mildew
In recent years, especially in northwest Russia, the infection of phlox with mycoplasma organisms in combination with powdery mildew is almost total. Plants affected by mycoplasmas can be found in Moscow, St. Petersburg, Ryazan and their suburbs, Kiev, Minsk, Chelyabinsk, Yekaterinburg, Ufa, Perm, Voronezh, Volgograd, Rostov-on-Don. There are reports of the spread of infection in Krasnodar, Omsk, Novosibirsk, Bashkiria, Kharkov, Yalta and other regions. Treatment of phlox in the spring of disease eliminates the spread of mycoplasma on the site.
The symptoms that cause mycoplasmas are similar to those seen with a viral disease. Mycoplasma organisms are close to viruses, but differ from them in cellular structure. Their reproduction occurs by dividing or decaying into a number of daughter cells.
The greatest harm phloxam causes pathogen jaundice asters (Leptomotropus callistephi) - parasitic mycoplasma microorganism.
The host of this disease is extensive and includes more than 200 plant species from the 60 families. It can be detected by the symptoms of the disease, which are specific in nature and can manifest themselves in the form of various anomalies during the entire vegetative period. It is usually combined with infection by the powdery mildew agent.
The spread of infection in the plant is systemic. Symptoms of the disease are noted on the leaves and flowers. The highest degree of manifestation of the disease by powdery mildew is observed in the period of budding and flowering. Therefore, only the treatment of phlox from powdery mildew in the spring and in the middle of summer can help prevent the massive destruction of buds.
In some cases, the disease begins with the lightening of the veins of the young leaf, then comes the general chlorosis (yellowing) of the leaves. Sometimes, in the early stages of development, the affected plants acquire a mosaic pattern. Old leaves may become reddish; re-growing - almost white (discolored). Patients with phloxes are far behind in growth, often there is an increased branching of the shoots (a lot of second-order thin shoots are formed) and a tendency to increased bushiness. Leaf leaves are often twisted up or down. The development of the inflorescence is usually delayed, greening of the buds is characteristic, and the open flowers have petals of a greenish color, sometimes depending on the variety with light browning. Observations have shown that the seeds on the affected plants phlox are not formed.
The main distributor of the disease are considered to be the cicadas of the Macrosteles genus. These are small (2-3 mm) winged sucking insects that feed on the sap of various plants, including those affected, and, when they fly to healthy ones, infect them. Particularly large relocation of tsikadok occurs when mowing weeds or lawn, then they in search of food move to the phlox bushes. The disease does not manifest itself immediately after infection, but through 30 - 60 and more days, and very often (with late infection - at the end of July or in August) it manifests itself only the next year. It depends on the growing conditions of phlox.
Many other insects can be carriers of the pathogen, for example:
The pathogen multiplies in the body of the carrier. Transmission of infection is also recorded during vegetative reproduction of phlox.
Many species of mycoplasmas live in weed vegetation (dandelion, plantain, black-headed osote, chicory, horse sorrel, chamomile, clover, etc.), which serves as their reserve. Mycoplasmal organisms overwinter only in living tissues - in the rhizomes of cultivated and weedy plants.
Effective measures to combat mycoplasmal diseases, as well as viral ones, have not been established. Limiting the spread of mycoplasma organisms is possible only by carrying out timely agrotechnical and phytosanitary measures, as well as the destruction of vectors of the pathogen and diseased plants. Affected phloxes are dug up, trying to seize the entire root system, and destroy.
Very often phlox diseases are associated with parasitic fungi, for the development of which moisture and a certain temperature are needed. The favorable combination of humidity and temperature determines their mass development and, accordingly, the appearance of diseases. The spread of fungal infection occurs with the help of wind, water, insects, people who care for plants. The infection remains on the affected plant debris, in the soil, in the sowing and planting material, as well as on perennial weeds.
With the strong development of powdery mildew in phloxes, the leaves dry out, as a result of which not only the ornamental nature of plants decreases, the quality and flowering period - all physiological processes are also disturbed in diseased plants, which negatively affects their general condition.
It should be noted that the degree of susceptibility of various species and varieties of phlox by fungal diseases is not the same.
To carry out preventive (preventive) measures, it is necessary to know the signs of the main diseases of phlox, and diseases of fungal origin, as a rule, are mainly characterized by the appearance of various types of blotches, necrosis and plaques on the leaves and shoots.
The most common and harmful fungal diseases affecting phlox include:
Verticillary wilt (pathogen - mushroom Vnticillium albo-atrum)
Mealy dew (causative agent - mushroom Erysiphe cichoracearum f. Phlogis)
Phomosis (pathogen - mushroom Phomaphlogis)
Also diseases associated with leaf spots caused by a number of pathogenic fungi: Altemaria tenuis, Septoria phlogis, S. phlogina, S. divaricatae, S. drummondii, Phyllosticta decussatae, Cercospora omphacodes.
Strict adherence to agrotechnical methods for the care of plants - regular irrigation, the use of mineral fertilizers with high doses of potash, timely preventive measures - increases the resistance of phloxes to pathogenic fungi.
Verticillium wilt. The causative agent of the disease is the fungus Verticillium albo-atrum. Withering phlox shoots is associated with damage to the plant's conductive system. A soil pathogen that, through the root system, damaged during planting or tillage (for example, cuts on loosening) or wounds inflicted by pests (for example, wireworms) penetrates the plant’s vascular system. Then it spreads, clogs it and poisons it with its toxins, as a result of which there is a sudden wilting of leaves and shoots. The leaves turn yellow, turn brown and dry, remaining hanging on the plants.
Observed species and varietal sensitivity to the pathogen. The fungus can affect all or part of the vessels. The nature of leaf wilting depends on it - general or one-sided. Strong plants lag in growth, rarely form normal inflorescences or die.
Most often, the symptoms of powdery mildew are characterized by wilting of the leaves and the tops of individual shoots on the phlox bush, which is associated with the loss of turgor by the cells and tissues of the plant. The main cause of death of the shoots is the lack of nutrients and water in the plant, which is caused by the cessation of their entry through the dead vessels. Externally, withering leaves and shoots usually look healthy and the disease resembles wilting and drying out due to lack of water, but darkening and necrosis of the vessels can be seen in the cross sections of the shoots, and under the microscope they can see a mycelium.
Mučnistaâ rosa It has a focal character, especially strongly manifested in acidic and light soils because of their weak microbiological activity. On rich humus soils with high biogenicity, the disease is less pronounced. The temperature favorable for the development of the disease is about 25 ° С, therefore the spread of the pathogen in July and August increases, and with a cooling in September, at the base of the stem, new healthy shoots sometimes develop. The application of large doses of nitrogen fertilizer also contributes to the development of the pathogen. According to some experts, the development of the disease can be provoked by the overwetting of the soil.
The primary source of infection is infected planting material, seeds collected from diseased plants, poorly rotted manure, compost and sawdust. It is noticed that strawberries, solanaceous and pumpkin ones are especially susceptible to Verticillium albo-atmm and are its accumulators.
The pathogen in the form of mycelium is retained in plant residues, and in the form of microsclerotia in the soil retains its viability for up to 15 years. Distributed everywhere.
Good results in the fight against verticillosis are brought in by the soil during the growing season of biofungicide Trichodermin in a dose of 2 g per plant or its analogues, for example, Glyocladin (one tablet is applied for one plant). Particularly valuable plants can be watered with Fitosporin-M biofungicide solution (strictly following the manufacturer's recommendations), diseased plants can be treated in the same solution, after which they are planted in a new place. You can also use Vitaros or Maxim 0,2% fungicide solutions for dressing rhizomes.
With mass infection and plant death from powdery mildew, it is not recommended to occupy these areas under phlox and other cultures susceptible to this disease for 10 years.
It is necessary to collect and be sure to destroy all affected plant debris at the end of the growing season.
Powdery Mildew Disease on Phloxes: treatment, what to treat in spring and how to get rid
Mildew on phloxes is caused by the causative agent of the disease - the fungus Erysiphe cichoracearum f. phlogis.
At the same time, such a disease of phlox as powdery mildew, symptoms, as a rule, appear in the second half of summer. First, on the leaves, and then on the surface of all the green parts of phlox (shoots, green parts of the inflorescence and sepals), a white, and later grayish-white powdery coating in the form of separate spots is formed, which gradually merge and completely cover the affected tissues. At the end of the summer and in the fall, among the mealy plaque (mycelium of the fungus), dotted dark brown or black fruit bodies appear, which represent the wintering form of the fungus.
The disease spreads very quickly, the affected tissue is destroyed, the leaves dry out, the plants bloom poorly, their decorative effect is greatly reduced. With a high degree of damage plants die. Therefore, treatment of such a disease of phlox as powdery mildew should be started as soon as you see the first signs.
The primary source of infection is last year’s plant residues of diseased plants. The application of large doses of nitrogen fertilizers favors the development of the pathogen. The disease is widespread.
And now we need to clarify how to treat phlox from powdery mildew and how to protect your plants from infection. The main thing in the fight against the disease of powdery mildew is proper agricultural technology and preventive measures. The traditional means of combating the disease are prophylactic treatments of plants with 0,5% solution of Bordeaux mixture or other copper-containing drugs.
Good results are achieved when treating plants with 0,1% solution of colloidal sulfur or a solution of soda ash and soap (0,4% + 0,4%). Before treating phlox from powdery mildew in spring, make sure that all affected parts of plants are removed.
For many years, an effective prophylactic agent was applied to powdery mildew in the Botanical Garden of Moscow State University - dusting plants with ground sulfur. For better quality of dusting, sulfur was mixed with lime fluff. It is recommended to spend two - three such dusting with an interval of 10 - 12 days. It is convenient to use gauze bags (preferably double), when shaking them over the plant, sulfur is sprayed evenly and falls on the leaves and other plant organs. Dusting is carried out in the early morning or evening hours, in warm calm weather with sufficient humidity. According to observations, dusting on dew gives good results.
It should be remembered that hydrogen sulfide, which infects the fungus Erysiphe cichoracearum, is formed when the air temperature is not lower than 18 - 20 ° С, and at temperatures above 25 ° С sulfur preparations can cause burns, so the plants should not be sprayed or pollinated during hot hours.
Before you get rid of powdery mildew on phlox, you need to clean the entire area and remove all plant debris.
How to deal with powdery mildew on phlox
In the fight against powdery mildew, a biological method can be successfully applied - spraying of phlox plants with liquid manure. For its preparation, well-rotted manure is poured with water (1: 3), insisted for three days and diluted three times. Spraying is carried out in the evening. Bacteria in the slurry destroy the mycelium of the causative agent. Before you deal with powdery mildew on phlox, you need to choose the most effective means for these purposes.
Currently, high rates in the fight against powdery mildew are achieved by preventive treatment of plants with solutions of fungicides of systemic action Topsin-M, Scor (Chistotsvet) or Topaz. Spraying is carried out from the beginning of the growing season of plants (May) with an interval between treatments 10 - 12 days.
Especially valuable plants can be treated with a solution of the fungicide Abig-Pik
When transplanting phlox areas need to dig deep. In the fall, cut off the shoots are collected and be sure to destroy.
Gray rot. The causative agent of the disease - the fungus Botrytis sgpegea
The fungus infects flowers, buds, leaves and stems, on which light growing spots are formed. The disease manifests itself in weakened plants into which the pathogen penetrates through wounds or damaged tissue. During the whole vegetation period, the development of the disease is promoted by high humidity of the air and soil, insufficient lighting, the absence of normal ventilation due to plant thickening, and excessive nitrogen nutrition. Different varieties of phlox have different resistance to the disease.
The fungus persists in plant debris and soil for 1-2 years. Spreads through the air, with raindrops, infected plant parts and soil.
All activities aimed at creating normal conditions of humidity, help to reduce the disease: thinning thickened plantings, proper watering without overwetting the soil, loosening.
With a strong spread of the disease, it is recommended to spray infected fungi with solutions of fungicides such as Abigak-Pik, Vitaros, Scor (Chistotsvet), Topaz, Topsin-M, Khom.
Fomoz. The causative agent of the disease - mushroom Phoma phlogis
In this disease, the root neck and the bases of phlox shoots are affected, where numerous spots appear. First, the disease covers the lower part of the shoots, mostly the oldest leaves. They form rather large, vague yellowish-brown round spots with a thin border. Small black dots (pycnidia) are formed on the spots. Leaves gradually curl and dry. Then the disease spreads upward, the affected tissues (leaves and shoots) become fragile, crack, break easily; the bush gradually becomes bare, the plant weakens, lags behind in growth, it blooms poorly, and sometimes it dries out before it can form an inflorescence.
The source of infection is plant residues affected by fomoses, in which the causative agent of the disease can last up to two to three years, as well as infected planting material, from which mass infection of plantings can occur. It is also possible the spread of infection and seeds.
There are cases when diseased seedlings that died at the very beginning of the growing season developed from diseased seeds.
The development of fomoz is favored by high humidity (60-80%) and warm weather. Infection is promoted by mechanical damage to the tissue by humans and insects, which facilitate the penetration of the infection into the plant. First of all, plants affected by unfavorable conditions of the plant (heavy, too acidic soil, excessive moisture, damage by soil insects, etc.) are affected. The disease is also promoted by damage to the root collar, deep planting, prolonged stay under water during heavy rains, and stagnation of irrigation water in the ravines of the site.
When the first signs of the disease appear, the plants are traditionally sprayed with 1% solution of Bordeaux liquids with an interval between 10 treatments - 12 days. Usually two treatments are enough. With the strong development of the disease, the number of sprays is increased to three or four. You can use other fungicides, such as copper-containing - Abiga-Peak or Hom. Spring preventive treatments are effective.
Good results are obtained by prepress treatment of the rhizomes and cuttings of phlox in solutions of the fungicides Vitaros, Maxim or in the solution of the biofungicide Fitosporin-M. Phosphate and especially potash fertilizers increase plant resistance to fomoz, an excess of nitrogen fertilizers, on the contrary, increases their susceptibility.
Phlox leaves curl: treating a disease
A characteristic symptom of the disease is the death of small areas of tissue in different places of the lamina. First, there are single spots, as the disease progresses, their number and size increase, very often they merge with each other. The shape of the spots may be different: rounded, angular, with a sharply defined or spreading edge. They may be brown, gray, white, with dark bordering or without it, with a bright halo around the spot, with a lighter central part, etc. In some cases, the dead part of the fabric falls out, and holes remain on the leaves. With the strong development of the disease, the leaves dry out, which negatively affects the general condition of the plant.
If phlox leaves curl, treatment of diseases should begin with the identification of characteristic signs. If it is spotting, then the diseases can be infectious (caused by fungi) and non-infectious, associated with burns or other causes.
If the disease is caused by fungi, then spores are usually formed on the spots. As the formation of sporulation infections spread. The spots are often given names for the mushrooms that cause them. For example, a disease that causes pathogens from the genus Septoria, is called Septoria. Sometimes the name indicates the color of the spots (white spot, black spot, etc.). For example, among the most common fungi - causative agents of leaf spots can be called Alternaria tenuis (causative agent of Alternaria), schilaria phlogis, S. phlogina, S. divaricatae and S. drummondii (causative agents of Septoria), Phyllosticta decussatae (causative agent of phyllosticycosis), Cercospora omphrostosis, Cercospora omphrostosmara ophrophytosis). ).
For the prevention of diseases associated with spotty leaves, it is recommended pruning, collecting and destroying infected plant debris in the fall, digging up areas, early spring mulching of phlox plantings with non-infected land, humus, peat chips in order to create favorable conditions for the development of competitive mycoflora.
In the spring and autumn, preventive spraying of phlox and the soil around them with solutions of copper-containing preparations of low concentration should be carried out.
During the growing season, spraying of plants affected by fungi, solutions of fungicides Abig-Pik, Vitaros, Scor (Chistotsvet), Topaz, Topsin-M, Khom, or others similar in action is carried out to combat the leaf spots. The frequency of use of fungicides depends on the degree of development of the disease. We recommend at least two sprays with an interval between 10-12 treatments for days, with a strong progression of the disease, three or four treatments are performed.