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Articles by Knud V. Weisberg
Category : Article
article id 5141,
category
Article
(1981).
A method for measurement of actue leaf injury on tobacco indicator plants.
Silva Fennica
vol.
15
no.
4
article id 5141.
https://doi.org/10.14214/sf.a15368
Keywords:
damages;
photography;
measuring methods;
air pollution;
bioindicators;
Nicotiana tabacum;
leaves;
damaged leaf area;
ozone
Abstract |
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Author Info
A technique for instrumental scoring of damaged leaves on tobacco (Nicotiana tabacum) indicator plants caused by ozone in the lower atmosphere is being developed. The leaves are photographed in situ with an integrated unit, which illuminates the leaf from behind and keeps the camera in a well-defined position. By using microfilm and a minus green filter, it is possible to obtain negatives where the necrotic flecks appear as dark spots on a white leaf. The negatives are scanned in a TV-system and the size of the damaged fraction of the leaf is calculated by a microprosessor and is shown as a percentage of the leaf.
-
Mortensen,
E-mail:
lm@mm.unknown
- Weisberg, E-mail: kw@mm.unknown
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