Rice growers have learned details on using a new fungicide that could help them with an untreatable form of sheath blight.

The new fungicide, Sercadis, is being sold by BASF. Its use has been approved for rice this year on 40,000 acres in Acadia, Evangeline, Vermilion, St. Landry and Jefferson Davis parishes where fungicide-resistant sheath blight has been found.

The disease first became evident two years ago near the Mowata area in northwest Acadia Parish.

The new fungicide is a carboxamide that interrupts the energy-producing function of cells. Existing fungicides until now were strobilurins and triazoles.

The new chemical can be tank-mixed with the triazole fungicides for increased protection. Two applications can be sprayed on a crop, with an overall limit of 9 ounces per acre.

BASF also recommends using a surfactant to keep the fungicide on a leaf surface to ensure absorption. The chemical should be applied between panicle differentiation and late boot stages.

“Use it where you know you’ve had a problem,” said LSU AgCenter plant pathologist Don Groth.

The disease has not been found at the LSU AgCenter Rice Research Station, but it has been detected in a field across a road from the station.

To slow the spread of the fungicide-resistant sheath blight, plant pathologists are urging farmers to clean their equipment before moving from one field to another.

Another disease, leaf blast, is bad this year, Groth said. “We actually had to spray a field at late tillering to keep it from dying.” 

The chemicals Quadris, Quilt and Stratego can be used to treat blast, which can be spread by wind.

But Cercospora disease is not showing up like it did with a major outbreak in 2006.

BASF representative Alvin Rhodes said approval by the Environmental Protection Agency came reluctantly. “We appreciate the LSU AgCenter and the Louisiana Department of Agriculture and Forestry for their work on that.”

The BASF product Priaxor, a mix of Sercadis and the fungicide Headline, has been approved by the EPA on soybeans for aerial blight.