Control of Heliothis Spp. Larvae on Cotton with Pyrethroids and Ovicides, 1984

Abstract

Abstract A full season study was conducted at the Plant Science Research Farm of the Mississippi Agriculture and Forestry Experiment Station, Mississippi State, MS and the Delta Branch Experiment Station, Stoneville, MS. The experiment was conducted in a randomized complete block with 4 replications. Plots were 4 rows (38-inch rows) by 50 ft with 2 buffer rows between plots at the Plant Sci. Res. Farm and 4 buffer rows at the Delta Branch Experiment Station. Insecticides were applied at the Plant Sci. Res. Farm with a boom-type sprayer calibrated to deliver 6.1 gal/acre total volume at 30 psi through two TX-4 nozzles per row. Treatments were applied on 26 Jul, 2, 14 and 20 Aug. All plots were oversprayed for boll weevil control with Guthion 2L (0.25 lb (AI)/acre) on 31 Aug, 12, 20, 28 Sep and 3 Oct. Plots were evaluated on 1, 16 and 24 Aug by making 5-ft whole plant counts in each plot. Yield data were collected by mechanically harvesting the center 2 rows of each plot on 21 Nov. Plots were sprayed at the Delta Branch on 19 Jul and 17 Aug. Heliothis spp. pressure was low throughout the season. However, plant bugs and spider mites were heavy throughout the season.Whole plant counts were made 24 Jul in each plot. Insect populations and plant damage were monitored on 20 Aug by examining 25 terminals and 25 squares per plot. Yield data were collected by mechanically harvesting one of the center rows on 5 Oct.