| Image |
Descriptor |
Description |
Photographer |
| 5368705 |
Asexual Spore |
Asexual spore-producing bodies called "sporangia" of the fungus Phytophthora parasitica var. nicotianae. When the sporangia is hollow-looking it has produced zoospores and they swam away in search of susceptible host tissue. |
Paul Bachi |
| 5338034 |
Culture |
Nonselective medium vs. selective medium: Trichoderma growing from root pieces on nonselective medium (left) vs. Phytophthora nicotianae growing from root pieces on selective medium containing hymexazole and vancomycin (right) |
Mary Ann Hansen |
| 1525665 |
Damage |
|
Department of Plant Pathology Archive |
| 1525661 |
Feature(s) |
sporangia |
Department of Plant Pathology Archive |
| 5368291 |
Sign |
Sporangium ready to release its zoospores. From narrowleaf madole variety. |
Paul Bachi |
| 5368292 |
Sign |
Zoospores swimming out of sporangium. From narrowleaf madole variety. |
Paul Bachi |
| 5368293 |
Sign |
Zoospores swimming away from sporangium. From narrowleaf madole variety. |
Paul Bachi |
| 1524161 |
Sign |
|
Department of Plant Pathology Archive |
| 5368706 |
Sign |
Asexual spore-producing bodies called "sporangia" of the fungus. When the sporangia is hollow-looking it has produced zoospores and they swam away in search of susceptible host tissue. KY-14XL8 |
Paul Bachi |
| 5368703 |
Sign |
Asexual spore-producing bodies called "sporangia" of the fungus. When the sporangia is hollow-looking it has produced zoospores and they swam away in search of susceptible host tissue. KY-14XL8 |
Paul Bachi |
| 5368704 |
Sign |
Asexual spore-producing bodies called "sporangia" of the fungus. When the sporangia is hollow-looking it has produced zoospores and they swam away in search of susceptible host tissue. KY-14XL8 |
Paul Bachi |
| 1525660 |
Sign |
|
Department of Plant Pathology Archive |
| 5368865 |
Symptoms |
Plants with Black shank wilt, turn yellow, and eventually die. Hybrid 403, a burley variety |
Tom Miller |
| 5368866 |
Symptoms |
Plants with Black shank wilt, turn yellow, and eventally die. Hybrid 403, a burley variety |
Tom Miller |
| 5368867 |
Symptoms |
Plants with Black shank wilt, turn yellow, and eventually die. Hybrid 403, a burley variety |
Tom Miller |
| 5368868 |
Symptoms |
Characteristic disking of pith tissue of the lower stem (shank) of an infected tobacco plant. Hybrid 403, a burley variety |
Tom Miller |
| 5373284 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373305 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373306 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373307 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373308 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373309 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373310 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373311 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373312 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373313 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373314 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373315 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373316 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373317 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373330 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373331 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373333 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373334 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373335 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373336 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373337 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373338 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373339 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373340 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373341 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373342 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373343 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373344 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373345 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373346 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373347 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373348 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373349 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373350 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373351 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373352 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373353 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373357 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373358 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373359 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373360 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373361 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373362 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373363 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373364 |
Symptoms |
|
Division of Plant Industry Archive |
| 5373365 |
Symptoms |
|
Division of Plant Industry Archive |
| 5377619 |
Symptoms |
|
Division of Plant Industry Archive |
| 5377620 |
Symptoms |
|
Division of Plant Industry Archive |
| 1525005 |
Symptoms |
Crown root on African violet |
Department of Plant Pathology Archive |
| 1525006 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525293 |
Symptoms |
|
R.K. Jones |
| 1525294 |
Symptoms |
|
R.K. Jones |
| 1525295 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525296 |
Symptoms |
|
R.K. Jones |
| 1525297 |
Symptoms |
|
R.K. Jones |
| 1525298 |
Symptoms |
|
R.K. Jones |
| 1525299 |
Symptoms |
|
R.K. Jones |
| 1525530 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525531 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525532 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525576 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525655 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525656 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525657 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525658 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525659 |
Symptoms |
|
Department of Plant Pathology Archive |
| 5368670 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank. Dark variety VA 359 |
Paul Bachi |
| 5368671 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank. Dark variety VA 359 |
Paul Bachi |
| 5368672 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank. Dark variety VA 359 |
Paul Bachi |
| 5368673 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank. Dark variety VA 359 |
Paul Bachi |
| 5368674 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank". Dark variety VA 359 |
Paul Bachi |
| 5368675 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank". Dark tobacco. |
Paul Bachi |
| 5368676 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank". Dark tobacco. |
Paul Bachi |
| 5368677 |
Symptoms |
Leaves with symptoms of the disease "Black shank" in this case called "Foliar Black shank". Dark tobacco. |
Paul Bachi |
| 1525662 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525663 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525664 |
Symptoms |
|
Department of Plant Pathology Archive |
| 1525666 |
Symptoms |
|
Department of Plant Pathology Archive |
| 5332059 |
Symptoms |
|
Charles Johnson |
| 5337026 |
Symptoms |
|
Mary Ann Hansen |
| 0027046 |
Symptoms |
|
Paul Bertrand |
| 0027047 |
Symptoms |
|
Paul Bertrand |
| 0027048 |
Symptoms |
|
Paul Bertrand |
| 0027049 |
Symptoms |
|
Paul Bertrand |
| 0027050 |
Symptoms |
|
Paul Bertrand |
| 0027066 |
Symptoms |
|
Paul Bertrand |
| 1149206 |
Symptoms |
1976 |
USDA APHIS PPQ Archive |
| 1149207 |
Symptoms |
1976 |
USDA APHIS PPQ Archive |
| 1149208 |
Symptoms |
1976 |
USDA APHIS PPQ Archive |
| 1149209 |
Symptoms |
1976 |
USDA APHIS PPQ Archive |
| 1234125 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1234126 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1234127 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235006 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235007 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235008 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235009 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235010 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235011 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235013 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235077 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235078 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1235079 |
Symptoms |
|
Clemson University - USDA Cooperative Extension Slide Series |
| 1402037 |
Symptoms |
The black shank fungus can infect tobacco plants of any age. In young seedlings, stems may decay near the soil surface and the root system may become partly or completely black. A dark lesion may extend up the stem. Symptoms are sometimes confused with damping-off caused by other organisms.
The photo above shows black shank damage as it appears in the field. Leaves may suddenly and uniformly wilt or droop, turn yellow, and hang down the stalk. Warm, moist weather conditions favor black shank development. Advanced stages of this disease may cause partial or complete decay of the root system.
The black shank fungus is soil-borne and is readily translocated by equipment or water movement to noninfested areas. Since the spores of the fungus are so mobile, distribution of the disease within a field may not be uniform. |
R.J. Reynolds Tobacco Company Slide Set |
| 1402038 |
Symptoms |
Stalks generally develop black lesions which may extend several inches above the ground |
R.J. Reynolds Tobacco Company Slide Set |
| 1402039 |
Symptoms |
Plants cut longitudinally reveal brown to black discoloration of the pith, which is often separated into discs. Discing may not occur in resistant varieties and only a small portion of the pith may be discolored. |
R.J. Reynolds Tobacco Company Slide Set |
| 1402040 |
Symptoms |
Black shank infection may occur on lower leaves of a plant due to spores being splashed onto them by hard rains. Large lesions (up to 3 inches) with a greenish-brown to yellow color are formed on the infected leaves. |
R.J. Reynolds Tobacco Company Slide Set |
| 1436051 |
Symptoms |
on outside of stem. |
Clemson University - USDA Cooperative Extension Slide Series |
| 1436052 |
Symptoms |
on inside of stem. |
Clemson University - USDA Cooperative Extension Slide Series |
| 1440049 |
Symptoms |
Black shank is primarily a disease of the roots and the lower stalk of the tobacco. The symptoms of black shank vary with weather conditions, age of plants, stage of disease development, degree of plant resistance, and virulence of the soil-borne fungal pathogen. Stunting is often the first symptom of black shank, but the disease is seldom recognized until plants wilt. At first, wilted plants will recover in the evening hours, but later become permanently wilted, with leaves turning yellow and hanging down the stalk. During the early stages of disease development, an examination of the plant will show a black discoloration of one or more of the larger roots and the interior of the lower stalk. As the disease progresses, the lower part of the stalk becomes black near the soil line, hence the name black shank. In advanced stages of the disease, the tissues in the center of the lower stalk become blackened, and as the pith dries, it becomes segmented into discs. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440050 |
Symptoms |
Black shank is primarily a disease of the roots and the lower stalk of the tobacco. The symptoms of black shank vary with weather conditions, age of plants, stage of disease development, degree of plant resistance, and virulence of the soil-borne fungal pathogen. Stunting is often the first symptom of black shank, but the disease is seldom recognized until plants wilt. At first, wilted plants will recover in the evening hours, but later become permanently wilted, with leaves turning yellow and hanging down the stalk. During the early stages of disease development, an examination of the plant will show a black discoloration of one or more of the larger roots and the interior of the lower stalk. As the disease progresses, the lower part of the stalk becomes black near the soil line, hence the name black shank. In advanced stages of the disease, the tissues in the center of the lower stalk become blackened, and as the pith dries, it becomes segmented into discs. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440051 |
Symptoms |
Black shank is primarily a disease of the roots and the lower stalk of the tobacco. The symptoms of black shank vary with weather conditions, age of plants, stage of disease development, degree of plant resistance, and virulence of the soil-borne fungal pathogen. Stunting is often the first symptom of black shank, but the disease is seldom recognized until plants wilt. At first, wilted plants will recover in the evening hours, but later become permanently wilted, with leaves turning yellow and hanging down the stalk. During the early stages of disease development, an examination of the plant will show a black discoloration of one or more of the larger roots and the interior of the lower stalk. As the disease progresses, the lower part of the stalk becomes black near the soil line, hence the name black shank. In advanced stages of the disease, the tissues in the center of the lower stalk become blackened, and as the pith dries, it becomes segmented into discs. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440052 |
Symptoms |
Black shank is primarily a disease of the roots and the lower stalk of the tobacco. The symptoms of black shank vary with weather conditions, age of plants, stage of disease development, degree of plant resistance, and virulence of the soil-borne fungal pathogen. Stunting is often the first symptom of black shank, but the disease is seldom recognized until plants wilt. At first, wilted plants will recover in the evening hours, but later become permanently wilted, with leaves turning yellow and hanging down the stalk. During the early stages of disease development, an examination of the plant will show a black discoloration of one or more of the larger roots and the interior of the lower stalk. As the disease progresses, the lower part of the stalk becomes black near the soil line, hence the name black shank. In advanced stages of the disease, the tissues in the center of the lower stalk become blackened, and as the pith dries, it becomes segmented into discs. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440054 |
Symptoms |
Black shank is primarily a disease of the roots and the lower stalk of the tobacco. The symptoms of black shank vary with weather conditions, age of plants, stage of disease development, degree of plant resistance, and virulence of the soil-borne fungal pathogen. Stunting is often the first symptom of black shank, but the disease is seldom recognized until plants wilt. At first, wilted plants will recover in the evening hours, but later become permanently wilted, with leaves turning yellow and hanging down the stalk. During the early stages of disease development, an examination of the plant will show a black discoloration of one or more of the larger roots and the interior of the lower stalk. As the disease progresses, the lower part of the stalk becomes black near the soil line, hence the name black shank. In advanced stages of the disease, the tissues in the center of the lower stalk become blackened, and as the pith dries, it becomes segmented into discs. |
R.J. Reynolds Tobacco Company Slide Set |
| 1497009 |
Symptoms |
Brown spot on tobacco |
University of Georgia Plant Pathology Archive |
| 1497010 |
Symptoms |
Black shank on tobacco |
University of Georgia Plant Pathology Archive |
| 1497011 |
Symptoms |
Phytophthora parasitica var. nicotianae; Tobacco black shank |
University of Georgia Plant Pathology Archive |
| 1497012 |
Symptoms |
Black shank on tobacco |
University of Georgia Plant Pathology Archive |
| 1497013 |
Symptoms |
Black shank tobacco |
University of Georgia Plant Pathology Archive |
| 1497014 |
Symptoms |
Black shank on tobacco |
University of Georgia Plant Pathology Archive |
| 1497015 |
Symptoms |
Black shank on tobacco |
University of Georgia Plant Pathology Archive |
| 1497059 |
Symptoms |
Black shank on tobacco |
University of Georgia Plant Pathology Archive |
