by Daren Mueller, Department of Plant Pathology, and Chuck Eckermann, Iowa Department of Agriculture and Land Stewardship
There has been some activity by the EPA concerning fungicides for soybean rust. The fungicide Caramba™ (metconazole), manufactured by BASF Corp., has been approved as a Section 18 fungicide in Iowa, effective on June 15, 2007. The exemption will expire on April 19, 2009. Caramba is a systemic, triazole fungicide with early infection and protectant activity. A second fungicide, Headline-Caramba™ copack, has been withdrawn by BASF and will not be available.
- All applicable directions, restrictions, and precautions must be followed. Listed are some restrictions for Caramba.
- Apply 8.2 to 9.6 fluid ounces metconazole active ingredient (a.i.) of Caramba fungicide per acre.
- A maximum of two aerial or ground applications of Caramba fungicide may be made at a 10- to 21-day retreatment interval.
- Caramba should not be applied within 30 days before harvest (PHI).
- A restricted entry interval (REI) of 12 hours must be observed.
- The supplemental label should be read for other restrictions and precautions.
Label status of fungicides for soybean rust in Iowa (updated June 22, 2007).
| Active Ingredient | Trade Name | Section 18 | Section 3 |
| azoxystrobin | Quadris | | Yes |
| azoxystrobin + cyproconazole | Quadris Xtra | Yes | |
| azoxystrobin + propiconazole | Quilt | Yes | Registered but awaiting final label |
| chlorothalonil | Bravo, Echo, Equus | | Yes |
| cyproconazole | Alto | Yes | |
| famoxadone + flusilazole | Charisma | Pending | |
| flusilazole | Punch | Yes | |
| flutriafol | Topguard | Yes | |
| metconazole | Caramba | Yes | |
| myclobutanil | Laredo EC, Laredo EW | Yes | Registered but awaiting final label |
| propiconazole | Tilt, PropiMax, Bumper | Yes | Registered but awaiting final label |
| propiconazole + trifloxystrobin | Stratego | | Yes |
| prothioconazole | ProLine | Pending | |
| pyraclostrobin | Headline | | Yes |
| tebuconazole | Folicur, Orius, Uppercut | Yes | Decision expected in mid-2007 |
| tebuconazole + pyraclostrobin | Headline SBR | Yes | |
| tetraconazole | Domark | Yes | Yes |
| tebuconazole + trifloxystrobin | Absolute | | Decision expected in late 2007 |
Daren Mueller is an extension plant pathologist with the Iowa State University Corn and Soybean Initiative. Chuck Eckermann is chief of the pesticide bureau of the Iowa Department of Agriculture and Land Stewardship.
This article originally appeared on page 194 of the IC-498(16) -- June 25, 2007 issue.
