ReviewA review of oak wilt management: A summary of treatment options and their efficacy
Introduction
Oak wilt, caused by the invasive fungal pathogen Ceratocystis fagacearum (Bretz) Hunt, is a serious disease of oaks (Quercus spp.) across portions of the eastern and central US. In August 2008, oak wilt was first detected in New York State (Jensen-Tracy et al., 2009). As oak wilt spreads, forestry professionals unfamiliar with the disease will need information regarding its biology and management. We intend for this review to be an initial resource providing an overview of this information. This review does not provide specific management recommendations, as these vary by region. We have included a brief review of the life history of C. fagacearum and a summary of control options and the role of prevention and education in oak wilt management. Previous reviews of oak wilt biology and management have been published by Appel (1995a), Juzwik (2000), and Wilson (2005).
Section snippets
Biology and symptoms
Oak wilt is a vascular disease infecting 33 oak species (Juzwik, 2000). Generally, infected red oaks (section Lobatae) have more severe symptoms than white oaks (section Quercus) and experience rapid and frequent mortality (Juzwik, 2000). However, white oak species native to Europe (Quercus petræa (Matt.) Liebl., Q. robur L., and Q. pubescens Willd.) are as susceptible to oak wilt as North American red oaks (MacDonald et al., 2001). Live oaks (section Quercus) are more susceptible than white
Oak wilt management
Oak wilt management is most often an integration of root disruption, sanitation, and chemical application. The goal of root disruption is to sever root connections, which can be root grafts in any oak species or common root systems in live oaks, between infected and healthy trees. Sanitation measures focus on eliminating potential inoculum sources. Chemical applications most commonly consist of intravascular (at the stem or root flare) injection of propiconazole.
Assessments of efficacy of oak
Summary
This review continues to support the USDA Forest Service recommendation that an effective oak wilt management program should address underground and overland spread of C. fagacearum. No single management tactic is capable of protecting susceptible oaks from both overland and underground spread in a consistent and effective manner (Table 1). However, by integrating root disruption, sanitation, and chemical application, effective best management practices can be tailored to address the specific
Acknowledgements
Partial funding for KAK and GLQ provided by the NSF IGERT: Risk Analysis for Introduced Species and Genotypes (NSF DGE-0653827). We thank J. Pokorny, USDA Forest Service, State and Private Forestry, for useful information on recommended oak wilt treatments. We also thank F. Homans, J. Juzwik, J. Pokorny, K. Smith, and two anonymous reviewers for helpful comments on previous drafts.
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2012, Rangeland Ecology and ManagementCitation Excerpt :While an increase in live oak is generally viewed positively due to its high preference as browse forage by goats in this region (Taylor and Kothmann 1990) and aesthetic appeal (Kreuter et al. 2004), large populations of live oak are currently being crippled in Texas by Ceratocystis fagacearum, a fungal pathogen that causes oak wilt (Appel 1995; Koch et al. 2010). An increase in the density and regeneration of live oak has led to highly interconnected root systems that facilitate the spread of oak wilt through common root systems and root grafts (Juzwik et al. 2008; Koch et al. 2010). Reducing current live oak densities or maintaining densities at presettlement levels is therefore a high priority (Koch et al. 2010).