Evaluation of Early Season Thrips Control on Cotton—Delta Location, 1989

Abstract

Abstract Fourteen treatments were evaluated for thrips control in cotton planted 26 May in sandy loam soil on the Delta Branch Experiment Station, Stoneville, MS. Plots were 4 rows by 50 ft with 4 rows of cotton planted between plots. Plots were arranged in a randomized complete block design. Granular materials were applied with granule applicator boxes on a John Deere planter. All other treatments except the Orthene treated seed were liquids and were applied with a CO2 powered sprayer with an 8002E nozzle positioned above and in line with the furrow to direct all the spray into the furrow at a rate of 5.3 gal/acre. Water was used as the carrier for sprayed insecticides. Thrips samples were obtained after collecting 10 plants at random from each plot, placing them in a quart jar and transporting them to the laboratory. In the laboratory the plants were washed with a few drops each of detergent and sodium hyperchlorite bleach/liter of water, and rinsed onto a 115 mesh sieve. The thrips were then rinsed onto filter paper for counting under a binocular dissection microscope. Plants were collected for sampling on 9, 15, and 21 Jun, and the plants from 21 Jun were measured from the point of soil contact to the apical meristem to evaluate plant height differences. Boll counts were made on 30 Oct. Based on the identification of adult specimens, the majority of the thrips were tobacco thrips. Western flower thrips, soybean thrips, and a very few miscellaneous species composed the remainder of the population.