Mettle 125 ME fungicide has been approved for control of powdery mildew in California grapes by the California Department of Pesticide Regulation.

Manufactured and marketed by Isagro USA, Mettle contains tetraconazole. This broad-spectrum fungicide is in the sterol biosynthesis inhibitor (SBI) class but contains a “tetrafluoroethoxy” group which is unique within the SBI class, according to Isagro. This group provides highly systemic properties resulting in improved fungicidal action compared to other SBI compounds, adds the company.

It has both preventive and post-infection activity and low active ingredient content to high performance ratio, according to the company. Mettle is formulated as a microemulsion (ME) giving it faster penetration and superior coverage characteristics and is rainfast within two hours.

The new grape fungicide has been extensively tested for several years by leading researchers in California, New York, Ohio and Oregon. “Mettle has performed equally well to newer DMI's, quinolines and combination products in our field trials over the past three years. It's exciting to have another product that will allow growers to rotate products for resistance management.” Says Doug Gubler, University of California, Davis, Extension plant pathologist.

Isagro's Web site (Isagro-usa.com) has additional information on the product.