Control of Colorado Potato Beetle on Irish Potato, 1997

The experiments were RCB designs with 5 replicates, each planted 02 Jun at Presque Isle, ME on land that was in clover in 1996. The 3.0-m space between blocks and the 1.8-rn space between the four-row plots were bare soil. All rows were hand-planted 0.9 m apart and 15.0 m long and the healthy Katahdin seed (ca. 75 g) were 30 cm apart. Fertilization and hilling practices were normal for the area. Early and late blight were controlled by 7 foliar applications of mancozeb. Furrow applications of insecticides were made by sprinkle can. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 5.6 kg/cm2 pressure and 0.47 kl/ha. Numbers of larvae and adults were counted weekly on 20 whole plants in the middle rows of each plot. When dates of count and application were the same, beetle counts were made prior to application of insecticides. Analyses of variance were calculated following transformations of data using log|0(x + 1). Transformed means of the sum of larvae and adult beetles were compared using Fisher’s LSD Test and then applied to the actual means. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 5.6, 6.6 and 10.3 cm. The average temperature for each of the same 3 months was 17.7, 20.8, and 18.3 deg. C.