Bacteriosis in the garden: how to protect green spaces. Types of bacterial plant diseases

cotton, tobacco, tomatoes, potatoes, cabbage, cucumbers, and some others. Lesions can be general, causing the death of the entire plant or its individual parts, appear on the roots ( root rot), in the vascular system (vascular diseases); local, disease-limited separate parts or plant organs, and also appear on parenchymal tissues (parenchymal diseases - rot, spotting, burns); may be mixed. A special place is occupied by those associated with the appearance of neoplasms (tumors).

pathogens Bacterial diseases plants- mainly non-spore-bearing bacteria from the families Mycobacteriaceae, Pseudomonadaceae, Bacteriaceae. Among them there are polyphagous bacteria that infect many plant species, and specialized ones that infect closely related plants of the same species or genus. Polyphagous bacteria cause the following most common bacterioses: wet rot, which severely affects potatoes, cabbage, onions, less often carrots, shag, tomatoes, and root cancer of various fruit trees, grapes. Specialized bacteria cause bacterial spot of beans, bacteriosis of cucumbers, black bacterial spot and bacterial canker of tomatoes, vascular bacteriosis of cabbage, tobacco grouse, black and basal bacteriosis of wheat, bacterial blight of stone fruits, pears, mulberries, citrus fruits, ring rot and black leg of potatoes, cotton gommosis , striped bacteriosis of millet and barley and other diseases. Origin and development Bacterial plant diseases depends on the presence of an infectious onset and a susceptible plant, as well as on factors external environment, by changing which it is possible to control the course of the infectious process. For example, bacteriosis of cucumbers in greenhouses develops only in the presence of liquid moisture and an air temperature of 19-24 °. By ventilating greenhouses and raising the temperature in them, it is possible to stop the development of the disease. Bacteria enter plants through various lesions and natural passages; for example, pathogens of various spots - through the stomata of leaves, burns of fruit trees - through the nectaries of flowers, vascular bacterioses of cruciferous - through water pores in the leaves. Transmission of pathogens of bacterioses is possible with seeds (cotton gommosis, etc.), with undecayed remains of diseased plants, during plant care, vaccinations, with air currents, rain splashes, insects, mollusks, nematodes.

Control measures: seed treatment, disinfection of seedlings and cuttings, soil in greenhouses and greenhouses; treatment of vegetative plants with bactericides or antibiotics; destruction of the remains of diseased plants; pruning of diseased shoots and disinfection of damaged branches; destruction of diseased plants; correct alternation crops in crop rotation fields; proper diet and water supply of plants; development of resistant varieties.

Lit.: Bacterial diseases of plants, ed. V. P. Israel, 2nd ed., M., 1960; Gorlenko M.V., Bacterial diseases of plants, 3rd ed., [M., 1966].

M. V. Gorlenko.

The nature of the external manifestation of bacterial plant diseases largely depends on which organs and tissues are affected by bacteria and what pathological processes occur in them.

The following can be distinguished main groups and types of bacterial plant diseases:

I. Diseases associated with the death of parenchymal tissues - parenchymal bacterioses. They are usually local. Among parenchymal bacterioses, spotting, burns, and rot occur.

Penetrating into the intercellular spaces of leaves, phytopathogenic bacteria cause rapid death of surrounding cells. This is manifested in the formation of spots most often angular shape.

Examples bacterial spotting can serve: spotting of leaves and fruits of walnut(pathogen Xanthomonas juglandis), currant leaf spot(pathogen Xanthomonas heterocea), perforated stone fruit spotting(Xanthomonas pruni) and others.

Among diseases like burn practical value have: bacterial blight pear(pathogen Pseudomonas piri), lilac burn (pathogen Pseudomonas syringae), mulberry burn (pathogen Pseudomonas mori). To the most important objects external quarantine applies fruit tree burn(pathogen Erwinia amylovora).

Bacterial rot occur when bulbs, tubers, fruits and seeds are damaged. Under the action of pectolytic enzymes of bacteria, the median laminae are destroyed. Affected tissues soften or turn into a slimy, foul-smelling mass (for example, when acorns are affected by bacteria of the genus Erwinia).

Xanthomonas juglandis:

Perforated spotting of stone fruits (Xanthomonas pruni):

II. Diseases associated with the growth of tissues - hyperplastic bacterioses. In diseases of this group, bacteria cause accelerated random cell division, sometimes accompanied by an increase in their size, which leads to the formation of cancerous tumors. Tumor-like cancer is found in many woody plants.

The most important types: transverse cancer of oak trunks(pathogen Pseudomonas quercus), tumor-like cancer of ash trunks(Pseudomonas fraxini), poplar bacterial canker(Pseudomonas remifaciens), tuberculate pine cancer(Pseudomonas pini), root canker of fruit trees and forest tree species (Agrobacterium tumefaciens, =Rhizobium radiobacter), olive and ash tuberculosis(Pseudomonas savastanoi).

Agrobacterium tumefaciens:

III. Diseases associated with vascular lesions - vascular bacterioses. Usually they are characterized by a general defeat of plants and manifest themselves in their wilting (drying out). Reproducing in xylem vessels, filling and clogging them with a thick mucous mass, bacteria disrupt the water supply from the roots to the aerial parts. In addition, bacteria release toxins that poison plant tissue. All these violations lead to the rapid death of the affected parts, and then the entire plant. Vascular bacterioses predominantly agricultural and flower crops are affected. On the woody plants they are less common. An example is willow bacterial wilt- a very dangerous quarantine disease caused by the bacterium Erwinia salicis.

Among bacteria, there are species that have the ability to dissolve mycelium and sporulation of fungi. They got the name mycolytic bacteria. They are used in forestry and agriculture to combat fungal plant diseases ( powdery mildew, lodging of seedlings, etc.).

At indoor plants there are a number of different diseases caused by, and various bacteria. Of course, it is best to prevent the disease than to try to save the flower for a long time. plant diseases caused by bacteria, sometimes often do not have a clear picture, and the symptoms of the disease are mixed. Therefore, all flower lovers should definitely know what they may encounter.

Plant diseases caused by bacteria are often easily confused with other diseases.. Bacterial diseases can have various manifestations, similar to the defeat of flowers by fungi or viruses. Unfortunately, effective means control of bacterial plant diseases in this moment no. And the existing control measures are not always effective. The fact is that pathogenic bacteria enter the body of plants through damage or the slightest holes in the leaves. Bacteria spread throughout the plant through conducting vessels. It is the reproduction of bacteria in the vascular system of flowers that leads to the development of various diseases plants.

bacterial rot

Do not forget that bacteria can also spread through plant tissues. In this case, one can observe various bacterial rot. Most often, such plant diseases can be observed in flowers with juicy fleshy leaves. Bacterial rot often begins with the root system of the plant, gradually moving to the root collar. But also the plant can begin to rot from the leaves or peduncles. Bacterial rot is usually caused by wrong condition plant content: excessive application of nitrogenous fertilizers or waterlogging of the soil.

Bacterial spotting and wilt

The development of a bacterial plant disease can also be indicated by the appearance spotting. Unlike fungal leaf infections, spots caused by bacteria do not have clear boundaries. Such spots increase in size very quickly, and the leaf itself dries and turns yellow. Wet plant conditions only contribute to the rapid spread of the disease.

bacterial wilt accompanied by a loss of general plant turgor. At first, this plant disease appears only at the tops. But soon the whole plant becomes very lethargic. This fading can also be caused fungal diseases plants. But unlike fungi, bacteria multiply in the vascular system of the plant, which delays the flow of water. The vital activity of bacteria is also accompanied by an abundant release of toxic substances. To distinguish bacterial wilt from late blight, just look at the cut of the shoot. Late blight is characterized by the presence of a brown ring of vessels.

bacterial cancer

Very often on healthy plants can be observed abnormal hardening and thickening of tissues. They are very similar to tumor growths. This plant disease is called bacterial canker. Most often, such bacterial plant diseases are found on begonias, Kalanchoe, oleanders and succulent spurges. Bacterial cancer is difficult to notice, because tumors appear on the roots and root neck. With a very rapid progress of the disease in the development of plants, growth retardation is observed. Later, the plant dies.

Most often, weakened plants suffer from bacterial cancer.: small tumors begin to appear on them ranging in size from a couple of millimeters to several centimeters. Over time, the tumors turn into sores that never heal. In the middle of the ulcers, you can observe the accumulation of mucus - a waste product of bacteria. If on such ulcers you notice small points of black sporulation, then the disease is caused by a fungal infection of the plant.

Any bacterial plant diseases are easier to prevent than to treat.. Therefore, be sure to disinfect the ground and inventory that you use. If you touch a diseased plant, be sure to disinfect your hands with alcohol so as not to transfer bacteria to healthy flowers. When transplanting plants into old pots, be sure to pour boiling water over them from the inside.

Bacteria-affected flowers can only be saved by initial stage disease development. Diseased areas of plants are removed, capturing a small part of healthy tissue. After each cut of the plant, scissors or a knife should be disinfected with alcohol. When all diseased areas are completely removed from the plant, the flower should be sprayed and watered with Bordeaux mixture or any other preparations that contain copper. If such measures did not help the plant, it will have to be burned. The pot in which the flower grew should be well scalded with boiling water.

Pathogens - bacteria Pseudornonas, Erwinia. Bacterial plant diseases are plant diseases caused by bacteria. They cause great harm to many plant species. Lesions can be general, causing the death of the entire plant or its individual parts, appear on the roots (root rot), in the vascular system (vascular diseases); local, limited to the disease of individual parts or organs of the plant, and also manifest itself on parenchymal tissues (parenchymal diseases - rot, spotting, burns); may be mixed. A special place is occupied by bacterioses associated with the appearance of neoplasms (tumors).

causative agents of bacteriosis- mainly non-spore-bearing bacteria from the families Mycobacteriaceae, Pseudomonadaceae, Bacteriaceae. Among them there are polyphagous bacteria that infect many plant species, and specialized ones that infect closely related plants of the same species or genus.

Polyphagous bacteria cause the following most common bacterioses: wet rot and root cancer of various fruit trees and grapes.

Specialized bacteria cause bacterial spot of beans, bacteriosis of cucumbers, black bacterial spot and bacterial canker of tomatoes, vascular bacteriosis of cabbage, tobacco grouse, black and basal bacteriosis of wheat, bacterial blight of stone fruits, pears, mulberries, citrus fruits, ring rot and black leg of potatoes, cotton gommosis , striped bacteriosis of millet and barley and other diseases.

The emergence and development of bacteriosis.

It depends on the presence of an infectious beginning and a susceptible plant, as well as on environmental factors, by changing which it is possible to control the course of the infectious process. For example, bacteriosis of cucumbers in greenhouses develops only in the presence of liquid moisture and air temperature of 19-24°C. Airing greenhouses and raising the temperature in them, it is possible to stop the development of the disease. Bacteria enter plants through various lesions and natural passages; for example, pathogens of various spots - through the stomata of leaves, burns of fruit trees - through the nectaries of flowers, vascular bacterioses of cruciferous - through water pores in the leaves. The development of bacteriosis is promoted in addition to high humidity and air temperature, the presence of water droplets on plants, as well as a lack of phosphorus and potassium, high soil pH.

The main types of bacterioses of indoor plants

wet rot

A fairly common disease of indoor plants is wet rot. The disease manifests itself in the softening and decay of individual areas on the leaves, petioles, roots and fruits of the plant. Bacteria secrete the enzyme pectinase into the leaf tissue, which causes tissue breakdown. Most often, the juicy and fleshy parts of plants are affected. First, a small shapeless spot appears on the leaves, gray, brown or black, which grows in size. Simply put, rotting begins on bulbs and tubers, often accompanied by bad smell. Under favorable conditions - in a warm and humid climate, the disease spreads very quickly. And the affected part or the whole plant turns into a sour mass.

The pathogen penetrates through mechanical lesions on the plant - even microscopic cracks and wounds. Remains in the soil plant remains. Therefore, disinfection of the soil is required before planting, and when pruning roots, tubers and bulbs, slices must be sprinkled with crushed charcoal. And disinfect the instrument with alcohol after each circumcision.

The development of the disease is provoked by the introduction of excessive doses of fertilizers, stagnation of water in the soil, dense, compacted soil, cooling of wet earth in pots, for example, in winter in a cool room.

Control measures:

The plant can be saved if the bacteriosis has not yet affected the entire vascular system or is local in nature (for example, rot began from the tip of the leaf). If the roots are rotten, then you can still try to root the top (if given plant rooted cuttings). If rotting affected only part of the roots, and above-ground part looks alive, you can try to save the plant - for this you need to free the roots from the ground, cut off all the rotten ones, transplant them into dry, prepared soil, water and spray with Bordeaux liquid (or copper-containing preparations). The infection will not spread to another plant standing next to, but all working tools and pots must be thoroughly disinfected.

Bacterial spotting, bacterial burn, vascular bacteriosis

The disease often affects young leaves and shoots. Bacterial spotting, depending on the type of pathogen, has different symptoms. The most characteristic picture is when small watery spots first form on the surface of a leaf or stem, which gradually turn black. Most often, the spots have an irregularly angular shape, and are limited to a yellow or light green border. The bacterium spreads most often along the veins. The spots grow, merge, the entire leaf turns black. Eventually the plant dies.

The optimal conditions for the development of bacteria are a temperature of 25-30°C and high humidity air. The death of bacteria occurs only at temperatures above 56°C. Bacteria of the genus Xanthomonas are resistant to desiccation and can tolerate low temperatures for a long time.

A variant of bacterial spotting is the so-called bacterial burn, which is caused by bacteria of the genus Pseudomonas. In this case, not spots appear on the plants, but rather large shapeless areas of blackening, which then dry out. It looks like this section of the leaf is burnt. If diseases are associated favorable conditions, then it develops, very quickly causing the death of individual parts and the death of the whole plant. A bacterial burn begins more often with young leaves, shoots and flowers. Bacteria enter plants through stomata or wounds, begin to multiply in the intercellular spaces of the leaf parenchyma. The incubation period for the development of the disease is 3-6 days, depending on the temperature. Bacteria persist in soil and on seeds.

Control measures:

On the horticultural crops apply the treatment of plants and dressing of seeds with the antibiotic phytolavin-300. At home, on indoor plants, spraying and watering the soil with a solution of Trichopolum is successfully used - 1 tablet of Trichopolum per 2 liters of water. Copper-containing preparations are also effective, such as Bordeaux mixture, copper sulphate.

Sources of infection:

Seeds are one of the most important sources of infection. During seed germination, they can infect seedlings, and then move through conducting vessels into plants and infect adult plants during the growing season. In addition, diseased seeds can serve as a source of infection, causing bacterioses to appear in areas where they did not exist before. The infection can also be spread by green plants, in which the bacteria are well preserved and transferred to new areas of the country together with infected plants (cuttings, budding materials - eyes). One of the main sources of infection with bacterioses are the remains of diseased plants. Phytopathogenic bacteria survive especially long and well in the woody parts of plants.

The soil as a source of infection does not pose a great danger. Numerous studies have shown that phytopathogenic bacteria, getting into the soil, quickly die under the influence of antagonist microbes (there is a kind of self-purification of the soil).

Some types of insects can also be a source of primary infection. A great danger in the spread of bacterioses is represented by raindrops with small particles of the remains of diseased plants, which are carried over long distances by wind and air currents (air itself does not play a role in the direct transmission of diseases). Phytopathogenic bacteria can also be carried by water - irrigation, water from rivers and other sources. And finally, in nature, nematodes play an important role in the spread of bacterioses.

Gamair, Phytoflavin can be used as prophylactic agents. And also Copper-containing preparations of contact or combined action (copper sulfate, kuproskat, oxychom, etc.) can help as preventive measure: Abiga-Peak, Bordeaux mixture, blue vitriol, Oxyhom, Hom.

Houseplants have a number of different diseases caused by pests, viruses, fungi and various bacteria. Of course, it is best to prevent the disease than to try to save the flower for a long time. plant diseases caused by bacteria, sometimes often do not have a clear picture, and the symptoms of the disease are mixed. Therefore, all flower lovers should definitely know what they may encounter.

Plant diseases caused by bacteria are often easily confused with other diseases.. Bacterial diseases can have various manifestations, similar to the defeat of flowers by fungi or viruses. Unfortunately, there are currently no effective means of combating bacterial plant diseases. And the existing control measures are not always effective. The fact is that pathogenic bacteria enter the body of plants through damage or the slightest holes in the leaves. Bacteria spread throughout the plant through conducting vessels. It is the reproduction of bacteria in the vascular system of flowers that leads to the development of various plant diseases.

bacterial rot

Do not forget that bacteria can also spread through plant tissues. In this case, one can observe various bacterial rot. Most often, such plant diseases can be observed in flowers with juicy fleshy leaves. Bacterial rot often begins with the root system of the plant, gradually moving to the root collar. But also the plant can begin to rot from the leaves or peduncles. The cause of bacterial rot is usually the wrong condition of the plant: excessive application of nitrogenous fertilizers or waterlogging of the soil.

Bacterial spotting and wilt

The development of a bacterial plant disease can also be indicated by the appearance spotting. Unlike fungal leaf infections, spots caused by bacteria do not have clear boundaries. Such spots increase in size very quickly, and the leaf itself dries and turns yellow. Wet plant conditions only contribute to the rapid spread of the disease.

bacterial wilt accompanied by a loss of general plant turgor. At first, this plant disease appears only at the tops. But soon the whole plant becomes very lethargic. Such wilting can also be caused by fungal diseases of plants. But unlike fungi, bacteria multiply in the vascular system of the plant, which delays the flow of water. The vital activity of bacteria is also accompanied by an abundant release of toxic substances. To distinguish bacterial wilt from late blight, just look at the cut of the shoot. Late blight is characterized by the presence of a brown ring of vessels.

bacterial cancer

Very often on healthy plants can be observed abnormal hardening and thickening of tissues. They are very similar to tumor growths. This plant disease is called bacterial canker. Most often, such bacterial plant diseases are found on, Kalanchoe, oleanders and succulent euphorbia. Bacterial cancer is difficult to notice, because tumors appear on the roots and root neck. With a very rapid progress of the disease in the development of plants, growth retardation is observed. Later, the plant dies.

Most often, weakened plants suffer from bacterial cancer.: small tumors begin to appear on them ranging in size from a couple of millimeters to several centimeters. Over time, the tumors turn into sores that never heal. In the middle of the ulcers, you can observe the accumulation of mucus - a waste product of bacteria. If on such ulcers you notice small points of black sporulation, then the disease is caused by a fungal infection of the plant.

Any bacterial plant diseases are easier to prevent than to treat.. Therefore, be sure to disinfect the ground and inventory that you use. If you touch a diseased plant, be sure to disinfect your hands with alcohol so as not to transfer bacteria to healthy flowers. When transplanting plants into old pots, be sure to pour boiling water over them from the inside.