Early-Season Control of Chinch Bugs in Corn with Soil Insecticides, 1989

Abstract

Abstract Pioneer 3320’ field corn was planted for Tests I—III on 6 Apr and for Test IV on 19 Apr in loessial silt loam (Gigger-Gilbert complex) at the Macon Ridge branch of the LSU Northeast Research Station. Granular insecticides were applied at planting using a 2-row John Deere Model 71 Flexi-Planter, modified to carry 1-pt jars of insecticide. Jars were inverted above funnels connected by flexible delivery tubes to either a 7-inch band or an in-furrow application. The diam of a single central fole in the lid of each jar, in combination with tractor speed, determined the rate of insecticide flow. Banded insecticides were applied in front of the press wheel and further incorporated by a drag chain attached to the rear of the planter. Liquid insecticides were applied using a carbon dioxode pressurized planter-mounted sprayer dispensing insecticide from 2-liter plastic bottles. Application pressure was 50 psi using a Tee Jet no. 11004 nozzle. Banded sprays were applied as 8-inch bands across the open seed furrow ahead of the press wheel. For in-furrow spray applications, nozzles were rotated 90° and the spray directed into the open seed furrow A drag chain behind the press wheel provided slight additional incorporation after closure of the seed furrow. Tests were conducted in a randomized complete block design with 4 replications, each treatment consisting of 2, 40-ft rows spaced 36 inches apart. Efficacy of insecticide treatments against chinch bugs in corn were determined by counting the number of chinch bugs/10 randomly selected plants in each insecticide plot (5 plants/row × 2 rows/plot × 4 replications) The number of chinch bug-damaged plants per 40 row ft was also counted in each insecticide plot (2 rows/plots × 4 replications). Data are reported as mean number of chinch bugs/10 plants and mean number of damaged plants/40 row ft.