Date of this Version
Sweet cherries provide a major source of income to Michigan fruit growers. Annual production in Michigan during the period 1963-1971 averaged 44 million pounds, or 18 percent of the national total (Smith, et al. 1973). Bird damage to Michigan cherries is a major problem. Although no figures are available on the extent of sweet cherry damage, Stone (1973) estimated that in 1972 bird damage to Michigan tart cherries amounted to 17.4 percent of the crop. According to growers we interviewed, damage to black sweet cherries is often more severe than to tart cherries. These growers also report some damage to white sweet cherries but, since whites are harvested before they ripen fully, they are less likely to be damaged than blacks. Because cherries are damaged primarily by species protected by the Migratory Bird Treaty Act, nonlethal means of controlling damage are required. One promising means is a chemical (methiocarb [3,5-dimethyl-4-(methylthio)phenol methylcarbamate = Mesurol]), which has shown good results when used as a nonlethal bird repellent on several crops (Guarino 1972). In 1971, Guarino, et al. (1974) applied methiocarb to half a row of 17 sweet cherry trees and to half a block of 22 tart cherry trees in Michigan. The trees within each treated area were sprayed to drip with a 75-percent methiocarb wettable powder formulation combined with 0.25-percent Dow Latex 512R (now Dow Latex 205) sticker. This sticker was added to improve retention of the chemical on the fruit. One pound active methiocarb per 100 gal. of water was sprayed at the rate of 6.4 gal. per sweet cherry tree (tart cherry trees were sprayed at the rate of 4.1 gal. per tree). Estimates of damage reduction were 80 percent in sweet cherries and 63 percent in tart cherries.