Pear, Codling Moth Control, 1980

A block of mature Bartlett pears (8x11 trees) was sprayed with 2 oz Al/a of diflubenzuron on Apr 25, May 16, Jun 5 and 27. An adjacent block (3 x II trees) served as an untreated check. The sprays were applied with a hand gun at 450-500 psi until the trees dripped. One hundred fruit were inspected weekly in each of the sprayed and unsprayed plots. Mt. St. Helens erupted 2 days after the 2d application and ca. I in. of ash was deposited on the orchard. Cool weather prevailed until early August and was followed by 2-3 weeks of hot weather.