Botrytis

Botrytis Blight on Wine Grapes

Botrytis affects many plant species, although its most notable hosts may be wine grapes. The blight can attach all parts of the plant except the roots. In horticulture, it is usually called “grey mold”. Standing water on plant leaf surfaces provides a place for spores to germinate. Humid conditions can result from improper irrigation practices, plants placed too close together resulting in inefficient ventilation and air flow (particularly in green houses).

The fungus removes water from the grapes, leaving behind a higher percent of solids, such as sugars, fruit acids and minerals. This results in a more intense, concentrated final product. The wine is often said to have an aroma of honeysuckle and a bitter finish on the palate. Botrytis produces an anti-fungal that kills yeast and often results in fermentation stopping before the wine has accumulated sufficient levels of alcohol.

Botrytis is known to be plant’s worst fungal enemy. It is also capable of producing mycotoxins. In contrast to widely held images of urban pollution and blight the persistence of an “agrarian myth” that associates life on the farm with healthful, bucolic joys ignores a fundamental reality: agriculture can be a dangerous occupation. It may act as a facultative (optional) pathogen in plants and is commonly considered as a contaminant.

It grows rapidly, reaching a colony size of 3 to 9 cm in diameter, following incubation at 25 degrees C for 7 days on potato glucose agar. The texture is woolly. The surface color is white at the beginning and becomes grey to brown in time. Dark spots may be observed on the surface of the colony. Reverse is dark.

It has septate, hyaline to brown hyphae and septate, brown, large conidiophores. Conidiophores branch at their apices. These branches terminate in vesicles which bear blastoconidia on their surfaces. The blastoconidia are located on short denticles, are hyaline to brown, one-celled, and round to oval in shape.

For treatment, symptoms, and more information see www.mold-survivor.com

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Suggested Reading / Abstract

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• • Moulds and Filamentous Fungi in Technical Microbiology, Olga Fassatiova, progress in industrial microbiology, Volume 22, Elsevier, New York, 1986. 233 p.

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• • Medical Mycology – The Pathogenic Fungi and the Pathogenic Actinomycetes, 3rd edition, John Willard Rippon, W. B. Saunders Company , Harcourt Brace and Jovanich, inc., Philadelphia, 1988. 797 p.

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• • Medically Important Fungi – A Guide to Identification, 2nd edition, Davise H. Larone, American Society for Microbiology, Washington, D. C. 1995. 274 p.

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• • National Research Council (NRC). 1981. Indoor Pollutants., National Academy Press: Washington, D. C.

• • Kozak, P. P., J. Gallup, L. H. Cummins, and S. A. Gilman. Factors of importance in determining the prevalence of indoor molds. Annuls of Allergy. 1979, 43:88-94.

• • Cassarett and Doull’s Toxicology – The Basic Science of Poisons, 4th edition, Amdur, M. O., Doull, J and Klaasen, C. D. eds. Pergamon Press, New York, 1991. 1033 p.

• • Indoor Air Pollution Control, Thad Godish, Lewis Publishers Inc, Chelsa, MI. 1989.

• • Air Sampling Instruments for the Evaluation of Atmospheric Contaminants, 7th edition, Susanne V. Hering, Tech. Ed. American Conference of Governmental Industrial Hygienist, Cincinnati, Ohio, 1989. 612 p.

• • WSL report CR 3511, DTI Aerobiological Standards Project, UK.

• • Flannigan, B. and Miller, J. D. 1993. Health implications of fungi in indoor environments – an overview. In Health Implications of Fungi in Indoor Environments (eds. R. A. Samson, B. Flannigan, M. E. Flannigan and S. Gravesen), Elsevier, Amsterdam (in press).

• • Flannigan, B and Miller, J. D. 1993. Humidity and fungal contaminants. In Bugs, Mold and Rot II, Proceedings of a Conference sponsored by BETEC, USDA and US Department of Energy, Washington, November, 1993 (in press).

• • Flannigan, B., McCabe, E. M. and McGarry, F. 1991, Allergenic and toxigenic micro-organisms in houses. J. of Applied Bacteriology Symposium Supplement. 70:61S-73S.

• • Atlas of Moulds in Europe causing respiratory Allergy, Foundation for Allergy Research in Europe, Edited by Knud Wilken-Jensen and Suzanne Gravesen, ASK Publishing, Denmark, 1984.

• • Practical Mycology – Manual for Identification of Fungi, Sigurd Funder, Broggers Boktr. Forlag, Oslo, Norway, 1953.

• • Crow, S. A., Ahearn, D. G., Noble, J. A. Moyenuddin, M. and Price, D. L. 1994 Microbial ecology of buildings: Effects of fungi on indoor air quality. American Environmental Laboratory p. 16-18.

• • Dangerous Properties of Industrial Materials, 7th Edition, N. Irving Sax and Richard J. Lewis, Sr., Van Nostrand Reinhold, New York, New York, 1989.

• • Grant, C., Hunter, C. A., Flannigan, B. and Bravery, A. F. 1988. The moisture requirements of moulds isolated from domestic dwellings, International Biodeterioration 25: 259-284.

• • Ayerst, G. 1969. J. of Stored Prod. Res. 5:127-141.

• • Biological Contaminants In Indoor Environments, ASTM STP 1071, Phillip R. Morey, James C. Feeley, Sr., James A. Otten, eds., American Society for Testing and Materials, Philadelphia, 1990.

• • Morey, P., Foarde, K., Klees, J., Streifel, A. “Microbiological Contaminants,” IAQ ’93 Operating and Maintaining Buildings for Health, Comfort and Productivity, ASHRAE Conference, Philadelphia, Penn. Nov. 8-10,1993.

• • Manual of Medical Mycology by John thorne Crissy, Heidi Lang, Lawrence Charles Parish, Blackwell Sciences, Cambridge, Massachusettes, 1995. 263p.

• • A Clinicians’s Guide to Fungal Disease by Stephen O. B. Roberts, R. J. Hay and D. W. R. Mackenzie, Marcel Dekker, Inc., New York, New York, 1994. 252p.

• • Manville, C. 1996. Poor drainage leads to fungal infestation, Adverse health effects. Indoor Air Quality Update. 3:11-12.

• Croft. W. A., Jarvis, B. B., and Yatawara, C. S. 1986. Airborne outbreak of trichothocene toxicosis. Atmos. Environ. 20:549-552.