Flutriafol Drench Provides Season-Long Protection of Boxwood Plantings Preinfected by Calonectria pseudonaviculata in the Mid-Atlantic.

Abstract

Flutriafol drench application on 7 March without and with additional applications at 8- and 20-week intervals all consistently protected boxwood plantings preinfected by Calonectria pseudonaviculata in two gardens in Richmond, Virginia, through 21 November. All drench applications were dosed at 2-ml product with 42% flutriafol and delivered in 250-ml solution per 30.5-cm shrub height in both gardens. While providing season-long protection, this drench dose also resulted in significant phytotoxicity on 30.5-cm-tall 'Justin Brouwers' boxwood but not on English and common boxwood, which were 1.4 and 1.1 m tall, respectively. Once the phytotoxicity issue is resolved, only a single drench per year may suffice to protect boxwood plantings in the Mid-Atlantic, which would substantially cut the labor cost and minimize the health impacts commonly associated with current fungicide foliar sprays.[Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.