Grapevine Trunk Disease
Eutypa lata, Botryosphaeria spp., Phaeomoniella chlamydospora, Phaeoacremoniu...
2 host plants · Fungal
Last updated
Grapevine trunks weaken and decline from internal fungal infection, often without obvious external signs until vines collapse. Multiple fungi cause different trunk diseases affecting vines. Prevent by using certified disease-free stock, making clean pruning cuts, and avoiding mechanical injury to trunk and cordons during management.
Prevention works better than treatment for grapevine trunk disease. Choose resistant varieties when they exist, site plants where air moves freely, and maintain good sanitation by removing debris and infected material. When chemical intervention is necessary, timing matters more than product: apply protectants before the infection window, not after symptoms appear.
Quick Reference
Management
Fresh pruning wounds, especially during wet weather (Nov-Mar in Puget Sound lowlands). Wounds made in early winter remain susceptible longer than late-winter wounds.
Ascospores released after 2+ hours of rainfall; airborne dispersal to fresh pruning wounds. Wounds remain susceptible 2-4 weeks post-cut; susceptibility decreases exponentially.
Cultural Controls
- Time pruning for dry weather windows
- Prune late in dormancy
- Remove cankers by pruning 4-6 inches below visible discoloration
- Burn or bag infected wood
- Sterilize tools between vines
- Train multiple trunks
Trunk disease pressure is elevated in the Puget Sound lowlands due to Nov-Mar rainfall coinciding with pruning season. Late February through mid-March pruning during dry spells is recommended to minimize spore dispersal during high-risk periods. Multiple Eutypa species may be present.
Host Plants (2)
Sources & References
Primary: PNW Plant Disease Management Handbook
- Frontiers in Plant Science (2023) DOI: 10.3389/fpls.2023.1063932