CHEMICAL REPELLENTS AND PLASTIC NETTING FOR REDUCING BIRD DAMAGE TO SWEET CHERRIES, BLUEBERRIES, AND GRAPES

We conducted 3 years of field tests comparing two chemicals [methyl anthranilate (MA, a natural compound used as a flavor additive) and Keyplex-350 (a proprietary micronutrient formulation)] that were reported to repel birds to exclusionary plastic netting and nontreated plots. Cumulative fruit damage from birds was monitored on sweet and tart cherry (Prunus avium L. and P. cerasus L.), blueberry (Vaccinium corymbosum L.), and wine grapes (Vitis vinifera x labrusca). Initial MA formulations caused injury to fruit and foliage. Two modified MA formulations with microencapsulation and photooxidation inhibitors provided significant reductions in bird damage and fruit splitting on sweet cherries in one of four experiments. A taste panel could not detect MA residues on sweet cherries at harvest. Bird damage was slightly reduced in MA-treated grapes, but damage to blueberries was similar in MA and control treatments. Keyplex did not deter birds from feeding on fruit and caused blemishes on and an unpleasant flavor in treated fruit. Many bird species were observed feeding on these fruit crops during successive years at the three experimental sites. Although these two chemicals have the potential to deter bird depredation, our work suggests that neither is consistently effective against all the frugivorous species in the northeastern United States. Chemical name used: 2-Aminobenzoic acid methyl ester [methyl anthranilate (MA)].