The Section 18 emergency exemption for diuron will allow producers to treat the blue-green algae that, when present in catfish ponds, has been linked to problems with off-flavor catfish.
The Section 18 label remains in effect from April 20 to Nov. 30, 2003, and applies to Diuron 80W, manufactured by Drexel Chemical Co., and Nautilus Aquatic Herbicide, manufactured by Griffin LLC. Mississippi producers were granted an emergency exemption for the algaecide in 2000, 2001, and 2002.
According to the exemption, the diuron products may be applied in or on commercial levee containing catfish ponds in Mississippi, by pouring a pre-mixed slurry from a bucket directly into the pond on the outflow side of the operating aerator.
The treatment may be applied at a rate of 0.5 ounces of product, or 0.4 ounces active ingredient, per acre foot. Application can be made every seven days, but may not exceed nine applications per year, or more than 0.225 pounds of active ingredient diuron per acre foot per year.
A maximum of 67,200 pounds of the active ingredient in Mississippi may be treated under the Section 18 exemption. In addition, the label advises producers to avoid any exposure of pond water treated with diuron to the federally listed endangered plant species of Price’s potato bean or pondberry.
For more information about the Section 18 label for diuron, contact the Mississippi Bureau of Plant Industry at (662) 325-3390.