| Image |
Descriptor |
Description |
Photographer |
| 0027061 |
Feature(s) |
|
Paul Bertrand |
| 1524154 |
Infestation |
|
Department of Plant Pathology Archive |
| 1402019 |
|
Blue mold can occur in the plant bed or field. Circular yellow spots up to one inch in diameter develop on the leaves. Blue-gray fungal growth is produced on the underside of these spots when the fungus is active. Spots become light brown when the leaf tissue dies. The disease first develops on lower leaves, but it rapidly spreads to upper leaves during wet, cool weather. |
R.J. Reynolds Tobacco Company Slide Set |
| 1524157 |
Sign |
|
Department of Plant Pathology Archive |
| 5368895 |
Sign |
Lower leaf surface with moldy growth on the fungus. Hybrid 403. |
Paul Bachi |
| 5368898 |
Sign |
Moldy growth of fungus on lower leaf surface. Hybrid 403. |
Paul Bachi |
| 5368896 |
Symptoms |
Spots on upper leaf surface beginning to become necrotic with slight yellow halo. Hybrid 403. |
Paul Bachi |
| 5368897 |
Symptoms |
Yellow to necrotic spots on upper leaf surface with faint yellow halo. Hybrid 403. |
Paul Bachi |
| 1524156 |
Symptoms |
Blue mold on tobacco |
Department of Plant Pathology Archive |
| 0027062 |
Symptoms |
|
Paul Bertrand |
| 0027063 |
Symptoms |
|
Paul Bertrand |
| 0027064 |
Symptoms |
|
Paul Bertrand |
| 0027065 |
Symptoms |
|
Paul Bertrand |
| 1233179 |
Symptoms |
in plant bed |
Clemson University - USDA Cooperative Extension Slide Series |
| 1233180 |
Symptoms |
in plant bed |
Clemson University - USDA Cooperative Extension Slide Series |
| 1402003 |
Symptoms |
Blue mold is shown above in a plant bed, but it can also occur in the field. |
R.J. Reynolds Tobacco Company Slide Set |
| 1402018 |
Symptoms |
Blue mold can occur in the plant bed or field. Circular yellow spots up to one inch in diameter develop on the leaves. Blue-gray fungal growth is produced on the underside of these spots when the fungus is active. Spots become light brown when the leaf tissue dies. The disease first develops on lower leaves, but it rapidly spreads to upper leaves during wet, cool weather. |
R.J. Reynolds Tobacco Company Slide Set |
| 5078063 |
Symptoms |
Blue mold of tobacco, lower leaf surface. |
Tom Creswell |
| 5257020 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257021 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257022 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257023 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257024 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257025 |
Symptoms |
|
Division of Plant Industry Archive |
| 5257026 |
Symptoms |
|
Division of Plant Industry Archive |
| 5265039 |
Symptoms |
seed bed |
Division of Plant Industry Archive |
| 5265040 |
Symptoms |
seed bed |
Division of Plant Industry Archive |
| 5265041 |
Symptoms |
|
Division of Plant Industry Archive |
| 5332070 |
Symptoms |
|
Charles Johnson |
| 5368662 |
Symptoms |
Yellow spots on upper leaf surface with corresponding moldy growth on lower leaf surface; seedling plants. Variety TN 86 |
Paul Bachi |
| 5368663 |
Symptoms |
Yellow spots on upper leaf surface with corresponding moldy growth on lower leaf surface; seedling plants.Variety TN 86 |
Paul Bachi |
| 5368665 |
Symptoms |
Yellow spots on upper leaf surface with corresponding moldy growth on lower leaf surface; seedling plants |
Paul Bachi |
| 1402020 |
Symptoms |
Systemic infection begins in leaf veins which turn reddish. Systemically infected stalks are stunted. The leaves are mottled and distorted. When a leaf is removed, discolored vascular tissue is present where the leaf was attached. Often, this discoloration extends down the stalk. The terminal bud may die, and the central portion of the stalk in the terminal bud region will be darkened or deeply discolored. Excessive numbers of ground suckers may develop. |
R.J. Reynolds Tobacco Company Slide Set |
| 1402021 |
Symptoms |
Systemic infection begins in leaf veins which turn reddish. Systemically infected stalks are stunted. The leaves are mottled and distorted. When a leaf is removed, discolored vascular tissue is present where the leaf was attached. Often, this discoloration extends down the stalk. The terminal bud may die, and the central portion of the stalk in the terminal bud region will be darkened or deeply discolored. Excessive numbers of ground suckers may develop. |
R.J. Reynolds Tobacco Company Slide Set |
| 1436044 |
Symptoms |
on upper leaf surface of seedling |
Clemson University - USDA Cooperative Extension Slide Series |
| 1436045 |
Symptoms |
on lower leaf surface of seedling |
Clemson University - USDA Cooperative Extension Slide Series |
| 1440008 |
Symptoms |
Blue mold can be very devastating to tobacco plants in the bed. Usually, the first symptom of blue mold in the bed is yellowed areas of diseased plants. The leaves of affected plants in these yellowed areas will have a cupped appearance, and the undersides of the leaves will show tell-tale, blue-gray downy fungal growth. Older plants can be deformed and twisted, and the main growing point eventually is killed. Veins in affected areas of twisted leaves are reddish-brown and can become necrotic. On older plants, definite yellow spots with bluish fungal growth on the underside of leaves can occur. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440015 |
Symptoms |
Blue mold may occur on the plant anytime from seedling to harvest; however, young tissue is more susceptible than old tissue. The first evidence of blue mold in the field usually occurs on the leaves as yellow circular spots about the size of a nickel. The spots soon develop the characteristic bluish, downy fungal growth on the undersides of the leaves which is best seen in the morning when the leaf is wet. If spots develop on leaves that are expanding, a puckering of the leaf occurs. As spots age, they turn from yellow to tan or brown and often tear or drop out. If infection has occurred near or on a leaf vein, a localized systematic infection may occur. The affected vein becomes reddish-brown, and the area around the vein is yellowed and distorted. In newly set transplants, it is possible for the fungus to develop systematically, killing the main bud and resulting in stunting or death of the plant. Splitting the stalk of systematically infected plants reveals a reddish- brown discoloration in the vascular tissue beneath the epidermis. A one-sided systemically infection also occur, resulting in a deformed stalk and lodging of affected plants. During weather favorable for blue mold (cool, cloudy, and wet), the disease can develop rapidly, causing numerous leaf lesions which can result in leaf blighting and severe leaf loss. The disease may develop during hot, humid periods if cool nights exist. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440016 |
Symptoms |
Blue mold may occur on the plant anytime from seedling to harvest; however, young tissue is more susceptible than old tissue. The first evidence of blue mold in the field usually occurs on the leaves as yellow circular spots about the size of a nickel. The spots soon develop the characteristic bluish, downy fungal growth on the undersides of the leaves which is best seen in the morning when the leaf is wet. If spots develop on leaves that are expanding, a puckering of the leaf occurs. As spots age, they turn from yellow to tan or brown and often tear or drop out. If infection has occurred near or on a leaf vein, a localized systematic infection may occur. The affected vein becomes reddish-brown, and the area around the vein is yellowed and distorted. In newly set transplants, it is possible for the fungus to develop systematically, killing the main bud and resulting in stunting or death of the plant. Splitting the stalk of systematically infected plants reveals a reddish- brown discoloration in the vascular tissue beneath the epidermis. A one-sided systemically infection also occur, resulting in a deformed stalk and lodging of affected plants. During weather favorable for blue mold (cool, cloudy, and wet), the disease can develop rapidly, causing numerous leaf lesions which can result in leaf blighting and severe leaf loss. The disease may develop during hot, humid periods if cool nights exist. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440018 |
Symptoms |
Blue mold may occur on the plant anytime from seedling to harvest; however, young tissue is more susceptible than old tissue. The first evidence of blue mold in the field usually occurs on the leaves as yellow circular spots about the size of a nickel. The spots soon develop the characteristic bluish, downy fungal growth on the undersides of the leaves which is best seen in the morning when the leaf is wet. If spots develop on leaves that are expanding, a puckering of the leaf occurs. As spots age, they turn from yellow to tan or brown and often tear or drop out. If infection has occurred near or on a leaf vein, a localized systematic infection may occur. The affected vein becomes reddish-brown, and the area around the vein is yellowed and distorted. In newly set transplants, it is possible for the fungus to develop systematically, killing the main bud and resulting in stunting or death of the plant. Splitting the stalk of systematically infected plants reveals a reddish- brown discoloration in the vascular tissue beneath the epidermis. A one-sided systemically infection also occur, resulting in a deformed stalk and lodging of affected plants. During weather favorable for blue mold (cool, cloudy, and wet), the disease can develop rapidly, causing numerous leaf lesions which can result in leaf blighting and severe leaf loss. The disease may develop during hot, humid periods if cool nights exist. |
R.J. Reynolds Tobacco Company Slide Set |
| 1440019 |
Symptoms |
Blue mold may occur on the plant anytime from seedling to harvest; however, young tissue is more susceptible than old tissue. The first evidence of blue mold in the field usually occurs on the leaves as yellow circular spots about the size of a nickel. The spots soon develop the characteristic bluish, downy fungal growth on the undersides of the leaves which is best seen in the morning when the leaf is wet. If spots develop on leaves that are expanding, a puckering of the leaf occurs. As spots age, they turn from yellow to tan or brown and often tear or drop out. If infection has occurred near or on a leaf vein, a localized systematic infection may occur. The affected vein becomes reddish-brown, and the area around the vein is yellowed and distorted. In newly set transplants, it is possible for the fungus to develop systematically, killing the main bud and resulting in stunting or death of the plant. Splitting the stalk of systematically infected plants reveals a reddish- brown discoloration in the vascular tissue beneath the epidermis. A one-sided systemically infection also occur, resulting in a deformed stalk and lodging of affected plants. During weather favorable for blue mold (cool, cloudy, and wet), the disease can develop rapidly, causing numerous leaf lesions which can result in leaf blighting and severe leaf loss. The disease may develop during hot, humid periods if cool nights exist. |
R.J. Reynolds Tobacco Company Slide Set |
| 1497016 |
Symptoms |
Peronospora tabacina; tobacco blue mold |
University of Georgia Plant Pathology Archive |
| 1497017 |
Symptoms |
Peronospora tabacina; Tobacco blue mold |
University of Georgia Plant Pathology Archive |
| 1497018 |
Symptoms |
Peronospora tabacina; Tobacco blue mold |
University of Georgia Plant Pathology Archive |
| 1497019 |
Symptoms |
Peronospora tabacina; Tobacco blue mold |
University of Georgia Plant Pathology Archive |
| 1497020 |
Symptoms |
Peronospora tabacina; Tobacco blue mold |
University of Georgia Plant Pathology Archive |
| 1497022 |
Symptoms |
Peronospora tabacina; Tobacco blue mold |
University of Georgia Plant Pathology Archive |
