Anti-desiccant Protection of Boxwood Crops from Infection by Calonectria pseudonaviculata Under Controlled Environments and in Production Fields

Chemical protection has been a key component of boxwood blight ( Calonectria pseudonaviculata, Cps) management programs, but each application of fungicides only protects the iconic evergreen landscape plant for 2 to 3 weeks at best. The objective of this study was to evaluate the potential of six film-forming anti-desiccant products—Anti-Stress 2000, AquaLock, Moisture-Loc, TransFilm, Vapor Gard, and Wilt-Pruf—for managing boxwood blight in lab experiments and in production fields. In lab experiments with container-grown Buxus sempervirens ‘Justin Brouwers’, TransFilm, Vapor Gard, and Wilt-Pruf consistently outperformed the other three products in suppressing Cps infection, sporulation, and spore release. Specifically, these three top performers reduced blight incidence by ≥90.7% when they were applied 1 day before plants were inoculated with Cps. Likewise, they reduced conidial count by ≥76.1% when applied 6 days after inoculation. Both Wilt-Pruf and TransFilm provided significant but lesser degrees of protection to field-grown boxwood crops in western North Carolina compared with their performance in the lab experiments. Comparatively, Wilf-Pruf had more consistent field performance than TransFilm. TransFilm protected B. sempervirens (“American”) only when applied monthly and B. sempervirens ‘Vardar Valley’ only when applied every 3 months. Wilt-Pruf protected both boxwood crops at both the monthly and 3-month application intervals. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .