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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Publications at this Location » Publication #426457
Research Project: Plant-associated Nematode Management and Systematics and USDA Nematode Collection Curation

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Developing fluopyram as a tool to combat beech leaf disease in managed landscapes and nurseries

Author
item BORDEN, MATTHEW - Bartlett Tree Company
item Reis Vieira, Paulo
item LITTLEJOHN, CAITLIN - Bartlett Tree Company
item ZACK, JACOB - Bartlett Tree Company
item SHERWOOD, MICHAEL - Bartlett Tree Company
item STILLER, AMBER - Bartlett Tree Company
item FITE, KELBY - Bartlett Tree Company
item LOYD, ANDREW - Bartlett Tree Company

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2025
Publication Date: 10/5/2025
Citation: Borden, M., Reis Vieira, P.C., Littlejohn, C., Zack, J., Sherwood, M., Stiller, A., Fite, K., Loyd, A. 2025. Developing fluopyram as a tool to combat beech leaf disease in managed landscapes and nurseries. Journal of Nematology. 57(1). Article e20250042. https://doi.org/10.2478/jofnem-2025-0042.
DOI: https://doi.org/10.2478/jofnem-2025-0042

Interpretive Summary: Beech leaf disease (BLD) is killing millions of beech trees across eastern North America. This emerging disease is associated with an invasive foliar nematode (a microscopic roundworm) introduced from Asia. The harmful impact of this nematode on both forest and ornamental beech trees highlights the urgent need for effective control strategies. In this study, a next-generation nematicide was evaluated across three field sites affected by BLD. Results demonstrated encouraging outcomes, with lower doses of the treatment significantly reducing nematode populations and disease severity. The nematicide-based management approach presented here is intended for arborists, nursery professionals, and plant health care providers working with beech trees. It may also be useful for conservationists managing native beech stands, curators of living collections in arboreta, and informed homeowners who cultivate beech trees as valued shade trees, hedges, or within woodlots.

Technical Abstract: Beech leaf disease (BLD), caused by the anguinid nematode Litylenchus crenatae mccannii (Lcm), has recently emerged as a severe threat to beech trees (Fagus spp.) in eastern North America. In response, the scientific community has accelerated research on this invasive pest, notably in studies of BLD pathophysiology that can be useful for developing management strategies, such as exploring the infection court and life stage targets. However, characteristics of both the pest and its host trees make BLD uniquely challenging to manage, leaving arborists, nursery managers, and plant health care specialists with limited treatment options. The first treatment demonstrated to directly affect Lcm and suppress BLD was a late-summer foliar application program using fluopyram a next-generation SDHI nematicide during the 2021-22 disease cycle. The three field trials described here expand on the initial field trial and associated bioassays, exploring several core variables that must be determined when developing a novel management program: site appropriateness, product dosage, and the timing of foliar applications. Our results support the efficacy of fluopyram-based programs in suppressing BLD but emphasize the importance of site conditions, noting that dense beech forests are unlikely to benefit. Results also show that significantly reduced product doses can yield excellent control. Finally, our findings suggest that initiating the foliar application program earlier in the summer could be equally or more effective than beginning in late summer. This information will guide implementation of novel management programs tailored to address the growing threat of beech leaf disease.