Assessment of New Fungicides for the Control of Southern Blight on Aucuba

Abstract

Abstract Drenches of Lynx 3.6F, ProStar 50W, Fluazinam 500F, Terraguard 50W, and Curalan DF were compared with Terraclor 75W for the control of southern blight on container-grown aucuba (Aucuba japonica) ‘Variegata’. Over the three-year test period, ProStar 50W and Fluazinam 500F across a range of rates completely protected aucuba from attack by the causal fungus, Sclerotium rolfsii. Also, both fungicides gave better disease control in two of three years than the current industry standard Terraclor 75W. Lynx 3.6F at the 0.54 g a.i./liter rate proved as effective in controlling southern blight as ProStar 50W and Fluazinam 500F. Terraclor 75W, which was applied at over twice the labeled drench rate, gave inconsistent disease control. Terraguard 50W and Curalan DF failed to provide effective control of southern blight on aucuba. No symptoms of phytotoxicity were observed.