Evaluation of Transplant Drench Fungicides for the Management of Clubroot in Spring-Planted Broccoli, 2024

Clubroot, caused by Plasmodiophora brassicae, is a longstanding, unresolved disease threat to Brassicaceae vegetable production in the United States. Swollen club-shaped galls form on the roots of affected plants; the distorted root system restricts the uptake of nutrients and water, leading to stunted growth, reduced marketable yields, and sometimes plant death. This report evaluates the efficacy of three commercial standard fungicides (Blocker 4F, Ranman, and Omega) and Elumin (not currently registered for use against clubroot) for the management of clubroot in spring-planted broccoli. This trial was conducted with a grower cooperator in Virginia. Results from the trial will help advise U.S. broccoli growers to identify the most effective currently available management options for this disease.