New fungicides for ornamental disease control

Jean Williams-Woodward, UGA Extension Plant Pathologist

Several fungicides for ornamental production have come on the market within the past couple of years. Below is a summary of some of the products.

Many of the products control Oomycete diseases including downy mildews and Pythium and Phytophthora root rot and blights. This is great news since there were few good Oomycete fungicide options available previously other than Subdue MAXX, Aliette and the numerous phosphonates/phosphites. Oomycete pathogens develop fungicide resistance readily.

Current research on Phytophthora and Pythium populations within GA nurseries and greenhouses has shown that approximately 5-25% of the isolates from individual production facilities are resistance to mefenoxam (Subdue MAXX). To reduce fungicide resistance development, always use products according to label rates and restrictions and rotate applications with products with a different mode of action (i.e. different FRAC numerical code).

Brand Name Active Ingredient FRAC # Sites1 Diseases Controlled
Adorn Fluopicolide 43 G, L, N Downy mildew, Phytophthora, Pythium: Must be tank mixed with a product with a different mode of action (different FRAC #) for fungicide resistance management
Disarm O Fluoxastrobin 11 G, N Broad spectrum – Rhizoctonia, Phytophthora, downy mildew, powdery mildew, anthracnose, leaf rusts, various fungal leaf spots and blights
Micora Mandipropamid 40 G, N Downy mildew and Phytophthora foliar blight and root rot: Provides a good rotation partner to Subdue MAXX, Segway and Adorn.
Orvego Ametoctradin + dimethomorph 45 + 40 G, N Downy mildew and Phytophthora: Contains the same active ingredient as Stature fungicide. Use in rotation with products with different mode of action.
Pageant Boscalid + Pyraclostrobin 7 + 11 G, L, N Broad spectrum – Anthracnose, powdery mildew, various fungal leaf spots, Botrytis, downy mildew, Phytophthora, Rhizoctonia, Cylindrocladium
Palladium Cyprodinil + Fludioxonil 9 + 12 G,L, N Provides good Botrytis control, plus other diseases including Rhizoctonia, powdery mildew, Cylindrocladium, Sclerotinia, Sclerotium rolfsii, Fusarium, certain fungal leaf spots
Segway Cyazofamid 21 G, L, N Downy mildew, Phytophthora, Pythium.
Torque Tebuconazole 3 G, L, N DMI fungicide with same mode of action as Strike, Banner MAXX, and Systhane. Controls powdery mildew, rusts, Sclerotium rolfsii, black spot, and various other fungal leaf spot diseases.
Tourney Metconazole 3 L, N For use on woody ornamentals (not floriculture). DMI fungicide. Controls anthracnose, powdery mildew, rusts.
Trinity TR Triticonazole 3 G, L, N Supplemental labeling for use on ornamentals. DMI fungicide. Controls anthracnose, powdery mildew, Fusarium, Rhizoctonia, Sclerotium rolfsii, Sclerotinia, certain fungal leaf spots
Veranda O, Affirm Polyoxin D 19 G, N Botrytis, Colletotrichum, Alternaria, Fusarium, Rhizoctonia, Sclerotinia

1  Location where product is registered for use: Greenhouse (G), Landscape (L), Nursery (N)