Effect of Use of the Bird Repellent Mesurol on Wine Composition and Flavor

Abstract

Gamay Beaujolais and Pinot blanc grapes were sprayed with three and four applications (64 oz. active ingredient per acre) of the experimental bird repellent, Mesurol [also known as methiocarb, 3,5-dimethyl-4-(methylthio) phenol methylcarbamate]. Wines were made from grapes harvested from two different vineyard sites one day and one week after the last chemical application. Mesurol residues of the finished wines in all cases were below 7 ppm. No differences were noted between treated and untreated wine or must compositions, with the exception of titratable acidity which was lower in Gamay Beaujolais treated musts than in the controls. Using duo-trio tests, no significant differences between treated and control wines were found in Pinot blanc wines at either harvest date. In one of the two field replications, a significant difference (p < 0.05) was found between treated and control wines made from Gamay Beaujolais grapes harvested one day after the last application of Mesurol. However, upon pooling correct responses for both sites, no significant difference was found. No significant differences were noted in the wines prepared from Gamay Beaujolais grapes harvested one week after the last application of Mesurol. Thus it may be concluded that the use of Mesurol, at levels similar to those used in this study, has no effect on composition or sensory properties of wines made from grapes harvested one week after the last application of Mesurol.