brown spot (Alternaria alternata ) on burley tobacco (Nicotiana tabacum (burley type)) - 1440025

brown spot
Alternaria alternata (Fr.) Keissl.

Host: burley tobacco (Nicotiana tabacum (burley type) L.)
Descriptor: Symptoms
Description: Symptoms of the brown spot fungus first appear on the lower leaves. Spots are brown with sharply defined margins and may be surrounded by yellow halos. The primary distinguishing characteristics of brown spot are the dark concentric rings within spots that give it a target-like appearance. With magnification, reproductive structures of the casual agent are seen as tufts of black fungal spores (conidia). Under severe conditions, spots are numerous, may coalesce, and give the leaf a ragged appearance as the infected tissue falls out.
Image type: Field
Image location: United States

Specimen Information

Specimen in collection: No
Specimen Condition:
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Photographer Information

Name: R.J. Reynolds Tobacco Company Slide Set
Organization: R.J. Reynolds Tobacco Company
Country: United States

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Image Number: 1440025

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Node Affiliation: Bugwood - UGA

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Image uploaded on Monday, January 01, 1990
Image Information last updated on Wednesday, March 02, 2011