Black spot leaf disease
Appearance
Black leaf | |
---|---|
Causal agents | potassium deficiency |
Hosts | grapevine |
Black Leaf is a physiological plant disorder that affects some grape varieties such as Concord. It is essentially a potassium deficiency that causes the leaves on a vine to turn purple and eventually black as chlorophyll is lost. For wine growers this lack of chlorophyll inhibits the vine's ability to transmit sugar to the grape, leaving the resulting grapes with a low brix count that may be less than ideal for wine making. [1]
References
- ^ R. Irvine & W. Clore The Wine Project pg 31 Sketch Publications 1997 ISBN 0-9650834-9-7
External links
- Photosynthesis and Chlorophyll Fluorescence in Blackleaf-Affected Concord Leaves - American Society for Enology and Viticulture
- Blackleaf in Grapes on www.extension.org