PROTECTING RIPENING SWEET CORN FROM BLACKBIRDS IN WISCONSIN WITH 4-AMINOPYRIDINE

Goodhue and Baumgartner (1965) described the use of a chemical, 4-aminopyridine (4AP), that causes birds ingesting it to emit distress calls and exhibit erratic flight behavior that frighten other birds from the Immediate vicinity. Using 4AP baits in Brown County, South Dakota, in 1965, De Grazio, et al. (1972) reported a savings of $6,449 worth of field corn at a cost of $634 for treatment. Baiting field corn with 4AP also provided significant protection from blackbirds in a study in northern Ohio in 1969 (Stickley, et al., 1976). Efficacy data gathered in these and other studies provided a basis for federal registration of 4AP in April 1972 as Avitrol FC Corn Chops-991, a cracked corn bait treated with three percent 4AP and diluted 1:99 with untreated cracked corn (EPA Registration No. 11649-12). From the results of these studies, we believed that 4AP might be similarly useful for protecting ripening sweet corn from damage by blackbirds. Canneries in Dodge County, Wisconsin, have reported that their contract growers have experienced heavy damage from blackbirds in over 400 ha of sweet corn in past years. Blackbird damage decreases not only the amount but the quality of corn for canning. This paper presents the results of a study conducted in Dodge County in August 1974 to determine the effectiveness and safety of Avitrol FC Corn Chops-99 for protecting ripening sweet corn from damage by blackbirds. It was conducted under an experimental permit (No. 11649-EXP-3G) granted by the Environmental Portection Agency on 27 June 1974. We thank Richard Wetzel, Robert Personius, and Richard Schraufnagel for their assistance in this study, James Peterson for analyzing sweet corn samples for 4AP residues, and David Bowden and Charles Breidenstein for statistical consultation. Test fields were made available by the Joan of Arc Cannery, Mayville, Wisconsin, and their contract growers, whom we thank for their cooperation