Colorado Potato Beetle Control, 1986

Abstract

Abstract Potatoes were planted on 8 May in South Deerfield, MA. Fertilizer was applied at planting (1000 lb/acre, 10N:10P:19K) and at first hilling (160 lbs/acre of urea 45). Soil was a fine sandy loam with a pH of ca. 5.3. The previous year potatoes were grown in the same field; therefore, Colorado potato beetle (CPB) pressure was heavy. Treatment blocks were replicated 4 times in a randomized complete block design. Each plot consisted of 2 30-ft rows with a 3 ft fallow area separating each plot. Applications were applied with a C02 pressurized sprayer at 40 psi, with a delivery rate of ca. 65 gal/acre. Applications were made on 18 and 19 Jun and on 3, 9 and 23 Jul. Foliar applications of Agrikelp (of 1.0 and 2.0 qt. formulation/acre) were applied on 29 Jun and 7 Jul. The synergist piperonyl butoxide (PBO) was tank mixed with Ambush treatments. Temik 15G applied at planting was administered to each seedpiece using calibrated hand scoops. Temik 15G (3.0) was applied at plant emergence on 3 Jun. CPB densities were determined by counting adults and larvae on 10 primary stalks in each plot. Densities were first determined 18 Jun before foliar treatments were applied. Early Temik treatments has already effected larval densities by this time. At mid-season, each plot was rated for defoliation on a scale from 1 (0-20%) to 5 (80-100%). When a treatment scored 5's in 2 of 4 plots, further treatment and evaluation was discontinued.