Grapevine Trunk Diseases---Eutypa Dieback

I am currently reading a research paper written in 2013 that goes into detail on the three major vine trunk diseases that can affect grape growers. Those diseases include eutypa dieback, esca and Botryosphaeria dieback. The review is a comprehensive discussion on (1) the symptomatologies in the trunk, leaves and berries, (2) the characteristics of the different fungal species associated with them, (3) the host–pathogen interactions and (4) disease management strategies. This review is 23 pages long so I thought that I would split the blog and focus on one disease at a time. Today's focus is on eutypa dieback.
Eutypa Dieback
Fungi Implicated

• The fungus Eutypa lata has a wide host range, occurring on more than 80 woody host species
• The fungus produces perithecial stroma on diseased grapevine wood
• Ascospores penetrate the plant by infecting susceptible pruning wounds during winter dormancy
• Ascospores are released throughout the entire year and are disseminated with each rainfall; but most spores appear to be released during winter or early spring, with relatively few being released during the summer months
• Eutypa dieback is associated with Eutypella vitis, Diatrype stigma, Diatrype whitmanensis, Cryptosphaeria pullmanensis and Cryptovalsa ampelina

Disease

• Symptoms are characterized by stunted shoots with shortened internodes, and small, chlorotic, cupped, tattered leaves with marginal necrosis and dead interveinal tissue
• Foliar symptom expression is mainly detected during the spring
• Most flowers dry before opening, and berries that develop from an infected spur position usually appear small and straggly
• After infection in the pruning wounds and colonization of the trunk vascular tissues and cordons, a brown, wedge-shaped necrosis usually develops
• Anatomical studies on the leaves of E. lata-infected grapevines showed changes in tissue ultrastructure including chloroplast degradation, lengthened thylakoids, cytoplasm lysis, bulked plastoglobules and endomembrane breakdown in severely affected leaves

Disease Management

• Remove infected trunks from the vineyard
• Best time to identify infected vines is spring (May and June) and when the leaf and shoot symptoms are most obvious; remove these shoots or mark them for later removal
• Sanitation is critical---all wood from infected plants must be removed from the vineyard and destroyed (either buried or burned), old infected trunks lying on the ground may continue to produce spores for several years
• Currently, no fungicide recommendations are available for control of this disease
• Painting large pruning wounds with a solution of fungicide has provided some level of control

References:
1. C. Bertsch M. Ramírez‐Suero M. Magnin‐Robert P. Larignon J. Chong E. Abou‐Mansour A. Spagnolo C. Clément F. Fontaine, Grapevine trunk diseases: complex and still poorly understood, Plant Pathology, Volume62, Issue 2, April 2013, Pages 243-265.
2. Illustration of Disease cycle of Eutypa Dieback from Ohio State University Extnesion.