P-685 - Baseline sensitivity and Field efficacy of florylpicoxamid against Botrytis cinerea in Strawberry

Botrytis fruit rot (BFR) of strawberry, caused by Botrytis cinerea, has impacted commercial strawberry production in Florida and other regions worldwide. The major source of inoculum is transplants quiescently infected from nurseries; hence the pathogen is reintroduced every season in Florida. Disease management relies on multisite fungicides during periods of low disease favorability, whereas single-site fungicides are recommended when environmental conditions favor disease development. However, widespread resistance has limited the efficacy of several commercially available single-site fungicides. Therefore, we studied the activity of florylpicoxamid, which represents a novel mode of action acting as a quinone-inside inhibitor, against B. cinerea. The spiral gradient dilution method was used to assess mycelial growth inhibition of 182 isolates collected from Florida strawberry fields from 2010 to 2023. The mean estimated EC₅₀ value for B. cinerea isolates was 0.024 µg/ml. The highest EC₅₀ value was 0.140 µg/ml, whereas the lowest EC₅₀ value was 0.008 µg/ml. The efficacy of a pre-mix formulation containing florylpicoxamid was evaluated in field trials during two strawberry growing seasons in Florida. The treatment reduced BFR incidence and provided similar control to standard products containing fludioxonil.  Our results support the potential of the new active ingredient florylpicoxamid as a future tool for the management of Botrytis Fruit rot of strawberry, pending product registration.