canker

canker,

small sore on the inside of the mouth. A canker appears as a shallow, whitish ulcer surrounded by a thin, red area. It is tender, sometimes painful, and may occur singly or as one of a group of sores. Cankers develop on the inner surfaces of the lips or cheeks, on the gums, under the tongue, or on the roof of the mouth. The cause is unknown, but cankers have been associated with friction, injury, allergy, and viral infection. They generally heal by themselves in a few days but can be recurrent.

Canker

a disease of cultivated and wild plants characterized by extreme, irregular proliferation of stems, branches, roots, and, less commonly, other organs, resulting in the formation of excrescences and tumors. Bacteria and fungi are the most common causative agents of canker. Some cankers heal very slowly or not at all. The use of the term “canker” is arbitrary. The most widespread and harmful cankers affecting crops are potato wart, crown gall, apple black rot, and bacterial canker of tomatoes.

Potato wart is a serious quarantine disease caused by an intracellular parasite—the pathogenic fungus Synchytrium endobioticum of the class Phycomycetes. The disease is characterized by the formation of fleshy nodular growths on the tubers and stolons and, less commonly, on the stems and leaves. The growths are sometimes larger than the tubers. A severely infected tuber is commercially worthless, and, as a rule, infected tubers cannot develop at all. The disease sharply decreases crop yield.

The causative agent of potato wart overwinters in the soil and plant residues in the form of spores. The spores germinate in spring, forming monociliated zoospores that penetrate the plants. The causative agents are spread by the tubers, postharvest residues, and manure; the spores remain viable even after passing through the intestinal tract of animals. Control measures include cultivation of potato varieties resistant to the disease, such as Kameraz, Berlichingen, and Priekul’skii Early. Other measures include keeping the fields in bare fallow, controlling solenaceous weeds, feeding affected potatoes to cattle only after they have been boiled, and disinfecting the soil with fungicides.

Crown gall, which affects fruit crops, is most dangerous in nurseries, especially when young plants are infected. The causative agent is the rodlike bacterium Bacterium tumefaciens, which can infect not only pomes and drupaceous plants (apple, pear, cherry, apricot, sweet cherry) but also willows, roses, chrysanthemums, beets, tomatoes, and sunflowers. The bacterium penetrates plants at the sites of injury to the root system and releases growth substances, such as indoleacetic acid and gibberellin-like substances, that intensify cell division and give rise to primary galls. Secondary galls often appear some distance away from the primary ones; they are usually sterile, since they result from the metabolic products of the bacteria moving through the tissues. The galls hinder the movement of juices, especially when the main root or the root collar (crown) is affected.

Control measures include establishing nurseries on plots where plants susceptible to crown gall were not grown for two or three years, growing healthy planting stock, discarding and burning seedlings with large galls on the main roots and root collar, and pruning away growths on the lateral roots and disinfecting the cut portions with copper sulfate or naphthenate.

Apple black rot, or apple canker, is a very dangerous disease. It most seriously affects weakened pomes (apple, pear, quince, medlar); less commonly, it affects drupaceous plants, persimmon, English walnut, and other plants in old neglected orchards. The causative agent, the pycnidial fungus Sphaeropsis malorum, penetrates plants at the sites of injury and attacks the bark, leaves, flowers, and fruits. Brown sunken spots appear on the bark, which gradually spread in concentric circles around the branches and trunk, causing them to wither. The affected areas resemble gooseflesh, owing to the formation of minute pycnidia under the epidermis. Apple canker is manifested on the leaves in the form of cinnamon-brown spots and on the fruits as black rot. Severely infected plants die in three or four years. The scion and stock must be compatible if the disease is to be prevented. It is recommended that disease-resistant varieties (Bel’fler-kitaika, Pepin Shafrannyi, Borovinka, Papirovka, Pepinka Litovskaia) be grafted into the crowns of vigorously growing stock with powerful root systems.

Control measures include uprooting dead trees, pruning overgrown branches, trimming away affected bark and then applying fungicides, applying tree coating to the wounds, collecting and burning rotted fruits and infected leaves, and coating boles and boughs with lime water.

Bacterial canker of tomatoes is caused by the bacterium Corynebacterium michiganense, which may be transmitted by seeds, infected residues, wind, and insects. Pruning during the growing season also causes the disease to spread. Canker of tomatoes attacks the fruits, stems, and vascular system, causing the branches and leaves to wither. Control measures include treatment of seeds, disinfection of soil with fungicides, thorough cleansing of the young crops before pruning, destruction of postharvest residues and replowing plots.

Cankers affecting trees may be caused by the bacterium Pseudomonas remifaciens (poplar and ash canker), the bacterium Pseudomonas pini (pine canker), the rust fungi Cronartium flaccidum and Peridermium pini, the ascomycetous fungus Dasyseypha willkommii (European larch canker), and the bacterium Erwinia multivora (blight canker).

REFERENCES

Peresypkin, V. F. Sel’skokhoziaistvennaia fitopatologiia. Moscow, 1969.
Zhuravlev, I. I., and D. V. Sokolov. Lesnaia fitopatologiia. Moscow, 1969.
Pospelov, S. M., M. V. Arsen’eva, and G. S. Gruzdev. Zashchita rastenii. Leningrad, 1973.

M. I. KHOKHRIAKOV

canker

[′kaŋ·kər] (plant pathology) An area of necrosis on a woody stem resulting in shrinkage and cracking followed by the formation of callus, ultimately killing the stem. (veterinary medicine) A localized chronic inflammation of the ear in cats, dogs, foxes, ferrets, and others caused by the mite Otodectes cynotis.

canker

1. an ulceration, esp of the lips or lining of the oral cavity 2. Vet sciencea. a disease of horses in which the horn of the hoofs becomes soft and spongy b. an inflammation of the lining of the external ear, esp in dogs and cats, resulting in a discharge and sometimes ulceration c. ulceration or abscess of the mouth, eyelids, ears, or cloaca of birds

canker

stomatitis

[sto″mah-ti´tis] (pl. stomati´tides) inflammation of the mucosa of the mouth; it may be caused by any of numerous diseases of the mouth or it may accompany another disease. Both gingivitis and glossitis are forms of stomatitis.
Causes. The causes of stomatitis vary widely, from a mild local irritant to a vitamin deficiency or infection by a possibly dangerous disease-producing organism. Inflammation may arise from actual injury to the inside of the mouth, as from cheek-biting, jagged teeth, tartar accumulations, and badly fitting dentures. Irritating substances, including alcohol, and tobacco, may also cause stomatitis. Other causes are infectious bacteria, such as streptococci and gonococci or those causing stomatitis" >necrotizing ulcerative stomatitis, diphtheria, and tuberculosis; the fungus causing thrush; or the viruses causing herpes simplex and measles. Extreme vitamin deficiencies can result in mouth inflammation, as can certain blood disorders. Poisoning with heavy metals, such as lead or mercury, can also cause stomatitis.Symptoms. There is generally swelling and redness of the tissues of the mouth, which may become quite sore, particularly during eating. The mouth may have an unpleasant odor. In some types of stomatitis the mouth becomes dry, but in others there is excessive salivation. Ulcerations may appear, and, in extreme cases, gangrene (gangrenous stomatitis).
Other forms of stomatitis may occasionally cause more severe symptoms, including chills, fever, and headache. Sometimes bleeding or white patches in the mouth can be seen. In thrush, the symptoms themselves may be slight (white spots in the mouth resembling milk curds) but the disease may give rise to serious infections elsewhere in the body. In some cases, stomatitis causes inflammation of the parotid glands.
Stomatitis resulting from certain diseases presents special identifying symptoms. Syphilitic stomatitis produces painful ulcers in the mouth; in scarlet fever the tongue first has a strawberry color, which then deepens to a raspberry hue; in measles, Koplik's spots appear.Treatment and Prevention. The treatment varies according to the cause. When the inflammation is caused by anemia, vitamin deficiency, or any infection of the body, both the underlying disease and the stomatitis are treated. Antibiotics often are effective against the infection and prevent its spreading to the parotid glands. Severe stomatitis can be a side effect of chemotherapy and radiation to the head and neck as treatment for cancer. Measures to alleviate the inflammation and promote healing include increasing fluid intake and using artificial saliva to minimize dryness and help buffer acidity in the mouth, avoiding liquids and foods that are chemically irritating or extremely hot, and frequent and consistent mouth care.

With proper care, many cases of stomatitis can be prevented. Cleanliness is essential, especially of the mouth, teeth, dentures, and feeding utensils. Infants may acquire mouth infection from the mother's oral flora, dirty bottles, or the mother's nipples. In the case of a prolonged fever or of any severe general illness, dryness of the mouth should be avoided by ingestion of increased amounts of fluids.angular stomatitis superficial erosions and fissuring at the angles of the mouth; it may occur in riboflavin deficiency and in pellagra or result from overclosure of the jaws in denture wearers. Called also perlèche.aphthous stomatitis recurrent aphthous stomatitis.denture stomatitis inflammation of the oral mucosa seen in some patients with new dentures or with old, ill-fitting ones, caused by Candida albicans; characterized by redness, swelling, and pain of mucosa that is in contact with the denture. Called also chronic candidiasis" >atrophic candidiasis and denture sore mouth.gangrenous stomatitis see noma.herpetic stomatitis herpes simplex involving the oral mucosa and lips, characterized by the formation of yellowish vesicles that rupture and produce ragged painful ulcers covered by a gray membrane and surrounded by an erythematous halo.stomatitis medicamento´sa stomatitis due to an allergic reaction to drugs ingested, absorbed through the skin or mucosa, or given by hypodermic injection. Principal symptoms include vesicles, erosion, ulcers, erythema, purpura, angioedema, burning, and itching.recurrent aphthous stomatitis a recurrent disease of unknown etiology, characterized by one or more small round or oval ulcer(s) on the oral mucosa, covered by a grayish fibrinous exudate and surrounded by a bright red halo. The lesions usually persist for 7 to 14 days and then heal without scarring. Called also aphthae, aphthous stomatitis, and canker sore.

can·ker

(kang'ker), Do not confuse this word with cancer or chancre.1. In cats and dogs, acute inflammation of the external ear and auditory canal. 2. In the horse, a process similar to but more advanced than thrush. The horny frog is generally underrun with a whitish, cheeselike exudate, and the entire sole and even the wall of the hoof may be undermined. [L. cancer, crab, malignant growth]

canker

(kăng′kər)n.1. Ulceration of the mouth and lips.2. An inflammation or infection of the ear and auditory canal, especially in dogs and cats.3. A condition in horses similar to but more advanced than thrush.4. a. A localized diseased or necrotic area on a plant part, especially on a trunk, branch, or twig of a woody plant, usually caused by fungi or bacteria.b. Any of several diseases of plants characterized by the presence of such lesions.v. can·kered, can·kering, can·kers v.tr. To attack or infect with canker.v.intr. To become infected with or as if with canker.

can·ker

(kang'kĕr) 1. In cats and dogs, acute inflammation of the external ear and auditory canal.
See: aphtha2. An outmoded term for aphthae. [L. cancer, crab, malignant growth]

canker

a plant disease giving a limited NECROSIS of affected tissue and caused by bacteria or fungi.

aph·tha

, pl. aphthae (af'thă, -thē) Avoid the misspelling/mispronunciation aptha.1. In the singular, a small ulcer on a mucous membrane. 2. In the plural, stomatitis characterized by intermittent episodes of painful oral ulcers of unknown etiology that are covered by gray exudate, are surrounded by an erythematous halo, and range from several millimeters to 2 cm in diameter; they are limited to oral mucous membranes that are not bound to periosteum, occur as solitary or multiple lesions, and heal spontaneously in 1-2 weeks.
Synonym(s): aphthae minor, aphthous stomatitis, canker sores, recurrent aphthous stomatitis, recurrent aphthous ulcers, recurrent ulcerative stomatitis, ulcerative stomatitis. [G. ulceration]

canker

can·ker

canker

can•ker

canker

canker

canker

canker

canker,

Canker

REFERENCES

canker

canker

canker

stomatitis

can·ker

canker

can·ker

canker

aph·tha

canker

Synonyms for canker

noun corruption

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noun fungal disease

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noun sore

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Synonyms for canker

noun anything that is injurious, destructive, or fatal

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verb to have a destructive effect on

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verb to ruin utterly in character or quality

Synonyms

Synonyms for canker

noun a fungal disease of woody plants that causes localized damage to the bark

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noun an ulceration (especially of the lips or lining of the mouth)

Synonyms

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noun a pernicious and malign influence that is hard to get rid of

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verb become infected with a canker

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verb infect with a canker

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