European Corn Borer Control in Minnesota Snap Beans, 1993

Abstract

Abstract This test was conducted on the University of Minnesota, Rosemount Experiment Station, in snapbeans planted 8 Jul. Plots consisted of three 30 ft (9.14 m) rows on 30 inch (0.76 m) centers. Two untreated border rows and 7 ft (2.13 m) alleys separated the plots. Treatments were arranged in a randomized complete block design with 4 replications. Treatments were applied 13 Aug using a moderate-clearance Spirit sprayer with 7 TX-10 hollowcone nozzles delivering 27 gpa (252.5 liters/ha) at 50 psi (3.51 kg/ cm2) and 3 mph (4.8 km/hr). All treatments included the sticker/extender Bond at 0.10 fl oz/gal (0.79 ml/liter). During application, wind speed averaged 4-5 mph (6.4-8.1 km/hr) and the temperature was 72°F (22°C). Plots were artificially infested using a ‘bazooka’ applicator on 10, 16 and 20 Aug. Plants were at 20% bloom, 25% pin-bean (beans ≤ 1 inch) and 95% pod growth stages, respectively. On each infestation date, 15-20 consecutive plants in one row of each plot were infested with approximately 25 first-instar ECB larvae/plant. Infestations were designed to evaluate the activity of each material 3-d pretreatment, 3-d posttreatment and 7-d posttreatment. Feral ECB moth flights during this time were low (18/night/light-trap at peak). All treatments were evaluated 16 Sep by selecting five consecutive plants from the center of each infested row. Total pods, pods with feeding damage and total ECB larvae were recorded. Because of poor survival at the 10 Aug infestation, and high-survival in most treatments for the 20 Aug infestation, data only for the 16 Aug infestation are summarized.