Corn Insect Pest Management with Selected At-Planting Insecticide and Starter Fertilizer Treatments, 1993

The insecticidal efficacy, effect on plant growth and corn seed yields of selected treatments applied as in-furrow sprays at planting (IFSAP) and in-furrow granules at planting (IFGAP) were compared to that of an untreated check in 2 tests. The area for Test 1 had been planted to a hairy vetch, Vicia villosa, winter cover crop. Native winter vegetation was allowed to cover the area in Test 2. Both tests received an application of Gramoxone X-tra (1.75 liters/ha) 2 wk pre-plant to terminate all vegetation. All plots also received Atrazine (3.5 liters/ha) + Roundup D-pak (3.5 liters/ ha) at planting. Plots consisted of 4 rows on 101.6 cm centers × 13.5 m. Treatments were arranged in RCBD with 4 replications. Corn was planted notill in a Gigger silt loam (pH = 6.4, 1.6% organic matter) on 13 Apr with a John Deere 7300 planter modified to apply treatments through a granular applicator hopper box or as a directed spray into the seed furrow. IFSAP treatments for Furadan 4F mixed with the starter fertilizer (11-37-0) were applied with a CO2 charged system calibrated to deliver 46.7 liters total spray/ha through Teejet 8004 flat fan nozzles (1/row) at 2.67 kg/cm2. IFSAP treatments for Furadan 4F without fertilizer were applied with a CO2 charged system calibrated to deliver 46.7 liters total spray/ha through Teejet 8004 flat fan nozzles (1/row) at 2.18 kg/cm2. Numbers of chinch bugs were recorded on 5, 10, and 19 May by sampling 10 plants in each plot. Cutworm spp. damage to plants was determined by recording all damaged plants on the center 2 rows of each plot weekly for 3 wk after plant emergence to obtain a cumulative summary. Plant stand density was measured on 27 May by sampling the entire 2 center rows of each plot. To determine corn plant maturity, tassels (no./m) were recorded on 18 Jun in each plot. Yields were measured by harvesting the 2 center rows of each plot on 27 Aug. The entire test was furrow-irrigated throughout the season and rainfall was not considered a factor influencing final yields.