First-Generation European Corn Borer Control Via Ground, Chemigation, and Aerial Applications, 1986

Studies I, II, and III were established in cornfields near Armour and Redfleld, S. Dak. Study IV was established in 2 adjacent fields near Chamberlain. Treatments in studies I and II were randomized in a complete block design with 3 replications and all treatments were ground applied in one-row plots (0.97-m centers), 30 m long. Applications were made on 25 Jun at Armour and on 1 Jul at Redfleld. The granular materials (Study I) were applied from a highboy in a 20-cm band over the whorl with a pneumatic applicator powered by a 3.5-horsepower engine. Granules were metered by Noble metring units driven via chain Irive by a 12 V DC motor. Liquid materials (Study II) were applied with a CO2 backpack sprayer with a hand-held wand. One 1.5 LE nozzle/row delivered 19.5 gal/acre at 15 psi and 3.5 mph. The treatments in Study III were applied through center pivot systems on 26 Jun (Armour) and 4 Jul (Redfleld). A Zimmatic low-pressure irrigation system delivering 0.25 inches of water was used at Armour, and a Valley low-pressure system delivering 0.20 inches of water was used at Redfleld. Treatments (not replicated) consisted of different sized wedges (6-40 acres) of the pivot circle. The treatments in Study IV were applied aerially with a fixed-wing aircraft on 26 Jun. All treatments were applied in 2 adjacent fields and analyzed as 2 replicates of a single experiment. Granular treatments were at least 2 aerial swath widths wide (27 m), and liquid treatments were a single swath in width (15 m). All treatments covered the entire length of the field (minimum 3 acres). Liquid treatments were applied using 3 gal/acre of carrier. Plots from all studies were evaluated 1 month after treatment. Studies I and II were evaluated by splitting stalks from 10 plants showing leaf feeding in each plot and rep. These plants were examined for European corn borer (ECB) cavities (2.5 cm of tunneling equals one cavitiy). Studies III and IV were evaluated by splitting 10 leaf-damaged plants for ECB navities in each of 5 areas within each treatment area.