Control of Aphids on Irish Potato, 1996

Abstract

Abstract The experiment was an RCB design replicated 5 times and was conducted at Presque Isle, ME on land that was in clover in 1995. It was planted 28 May. The 3.0-m space between blocks and the 1.8-m space between the four-row plots were sown to oats on 19 Jun. All rows were planted with an assisted-feed planter 0.9 m apart and 15.0 m long and the healthy whole Katahdin seed (approx. 75 g) were 30 cm apart. Fertilizer and hilling practices were normal for the area. Early and late blight were controlled by 7 foliar applications of mancozeb. Fur-row 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 (80 psi) pressure and 0.47 kl/ha (50 gpa). Numbers of aphids (by species) were counted on a top, a middle, and a bottom leaf on 20 plants in the middle rows of each plot. When dates of count and application were the same, aphid counts were made prior to applications of the insecticide. Analy-ses of variance were calculated following transformation of the data using log10(x +1). Transformed means of the total number of wingless aphids 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 8.5, 11.8, and 6.2 cm. The average temperature for each of the same 3 months was 18.3, 19.4, and 20.0 deg. C.