Fungal disease
Fungal disease in viticulture refers to a group of plant diseases caused by pathogenic fungi that affect grapevines and have a significant impact on yield, fruit quality and vineyard longevity. Fungal pathogens are among the most persistent biological threats in winegrowing regions worldwide and require continuous management throughout the growing season.[1]
Overview
Fungal diseases develop when environmental conditions favour spore germination, infection and spread, most commonly under combinations of moisture, warmth and limited air circulation. Grapevines are particularly susceptible because of dense canopies, long growing seasons and the high economic value of the crop.[2]
Disease pressure varies by climate, site and variety, and is strongly influenced by rainfall patterns, humidity and temperature during the growing season.[3]
Major fungal diseases
The most economically important fungal diseases of grapevines include:
- Powdery mildew (Erysiphe necator), which affects leaves, shoots and berries and can develop even under relatively dry conditions.
- Downy mildew (Plasmopara viticola), favoured by warm, wet weather and capable of causing severe defoliation and crop loss.
- Botrytis bunch rot (Botrytis cinerea), which may be either destructive or desirable depending on timing and wine style.
- Black rot (Guignardia bidwellii), particularly problematic in humid continental climates.
- Anthracnose and various wood diseases, which reduce vine vigour and lifespan.[4]
Effects on grape quality
Fungal infections can reduce photosynthetic capacity, delay ripening and directly damage berries. Infected fruit may show altered sugar accumulation, reduced acidity control and compromised phenolic development. Secondary effects include increased risk of off flavours, oxidation and microbial instability during winemaking.[5]
The susceptibility of grape varieties varies widely, with thin skinned cultivars generally more vulnerable than thicker skinned types.[6]
Vineyard management
Control of fungal disease relies on an integrated approach combining cultural, chemical and biological strategies. Key measures include canopy management to improve air flow and sunlight exposure, careful site selection and drainage, and monitoring weather conditions to anticipate infection risk.[7]
Fungicide programmes remain common, though increasing emphasis is placed on resistance management, reduced application frequency and environmentally sustainable practices.[8]
Resistant varieties and sustainability
Disease resistant grape varieties, often referred to as [[PIWI varieties]], have been developed through targeted breeding to reduce reliance on chemical treatments. These varieties play a growing role in regions seeking to lower environmental impact and adapt to changing climate conditions.[9]
International organisations promote integrated pest management and sustainable viticulture as long term responses to fungal disease pressure.[10]
Economic and regulatory impact
Severe disease outbreaks can lead to substantial economic losses through reduced yields, increased production costs and stricter regulatory controls on vineyard practices. In some regions, disease pressure has influenced appellation rules, authorised varieties and vineyard density requirements.[11]
See also
References
- ↑ Jancis Robinson, Oxford Companion to Wine, Oxford University Press, 17 Sept. 2015. ISBN 9780198705383.
- ↑ Markus Keller, The Science of Grapevines: Anatomy and Physiology, Academic Press Inc, 19 Jan. 2015. ISBN 9780124199873.
- ↑ Jones et al., Climate Change and Global Wine Quality, Wiley, 2012, ISBN 9781118450048.
- ↑ Pearson & Goheen, Compendium of Grape Diseases, APS Press, 1994, ISBN 9780890541581.
- ↑ PhD Jackson, Ronald S., Wine Science: Principles and Applications, Academic Press Inc, 14 April 2020. ISBN 9780128161180.
- ↑ Jancis Robinson, Jose Vouillamoz, Julia Harding, & 0 more, Wine Grapes: A Complete Guide to 1,368 Vine Varieties, Including Their Origins and Flavours, Ecco, 1 Nov. 2012. ISBN 9780062206367.
- ↑ Wilcox et al., Grape Diseases and Pests, Cornell University Press, 2015, ISBN 9780801452401.
- ↑ OIV, “Vine health and protection”.
- ↑ Becker, PIWI Grape Varieties, Ulmer, 2014, ISBN 9783897983863.
- ↑ FAO, “Plant disease management in viticulture”.
- ↑ Anderson & Nelgen, Global Wine Markets, University of Adelaide Press, 2011, ISBN 9780987073051.