Black Spot of Rose – This page contains extracts from IFAS
For chemical control, an initial application of a protectant fungicide should be made at bud break, followed by bimonthly applications until leaves are completely expanded. During the summer, applications every 7–14 days may be necessary to successfully manage the disease. Fungicides labeled for the control of black spot of roses in Florida are listed in Tables 1 and 2. For managing fungicide resistance, the best strategy is to rotate among products with different modes of action. All fungicides within the same group (with the same number or letter) have the same active ingredient or a similar mode of action. Fungicide resistance is usually low with multi-site inhibitor fungicides group (M).
Table 2.
Fungicide products marketed toward homeowners for control of black spot on roses.
Trade name | Active ingredient | Fungicide group |
Hi-Yield Captan Fungicide, Bonide Captan Fruit and Ornamental | Captan | M4 |
Ferti-lome Liquid Fungicide, Bonide Fung-onil Multipurpose Fungicide, Monterey Bravado Fungicide, Ortho Garden Disease Control | Chlorothalonil | M5 |
Monterey Liqui-Cop | Copper ammonium complex | M1 |
Ferti-lome Blackspot Powdery Mildew Control, Hi-Yield Copper Fungicide | Copper hydroxide | M1 |
Bonide Copper Dust or Spray, Dexol Bordeaux Powder | Copper sulfate | M1 |
Bonide Mancozeb Flowable | Mancozeb | M3 |
Spectracide Immunox Multipurpose Fungicide | Myclobutanil | 3 |
Bonide Rose Rx 3-in-1, Ferti-lome Triple Action Plus, Monterey 70% Neem oil | Neem Oil | NC |
Bonide Remedy | Potassium bicarbonate | NC |
Ferti-lome Systematic Fungicide, Bonide Infuse | Propiconazole | 3 |
Bonide Sulfur Plant Fungicide, Ferti-lome Dusting Sulfur, Green Light Wettable Dusting Sulfur, Hi-Yield Dusting Wettable Sulfur, Safer Garden Fungicide | Sulfur | M2 |
Bayer Advanced Garden Disease Control for Roses, Flowers, & Shrubs | Tebuconazole | 3 |
Ferti-lome Halt Systemic Fungicide, Green Light Systemic Fungicide | Thiophanate-methyl | 1 |
Ortho Rose Pride Rose & Shrub Disease Control | Triforine | 3 |
Ziram 76 DF, Ziram granuflo | Ziram | M3 |
Fungicide Group (FRAC Code): Numbers (1–37) and letters (M) are used to distinguish the fungicidal mode of action groups. All fungicides within the same group (with same number or letter) indicate same active ingredient or similar mode of action. This information must be considered in making decisions about how to manage fungicide resistance. M=Multi-site inhibitors, fungicide resistance is low; NC= not classified. Source: http://www.frac.info/ (Fungicide Resistance Action Committee, FRAC). Be sure to read a current product label before applying any chemicals. |
Fungicides on hand to be used in rotation
- Contact
- Daconil fungicide, Chlorothalonil, Frac M5
- Mancozeb, Frac M3
- Copper hydroxide, Frac M1 – Ferti-lome Blackspot Powdery Mildew Control, Hi-Yield Copper Fungicide
- Systemic – Propiconazole, Frac 3