Evaluation of Thrips Densities in At-Planting Seed and Soil Treatments on a Gigger Silt Loam Soil, 1997

Plots were replicated four times in a RCB design and were 4 rows (40 inch centers) X 45 ft. ‘Stoneville 474’ cotton seed was planted on a Gigger silt loam soil 7 May. Cotton seed was planted at a rate of 4 seed/row ft with John Deere 7100 series planter which was equipped with 10-inch seed cones mounted to replace the seed hoppers. Granular in-furrow treatments were applied with standard granular applicators. In-furrow spray treatments were applied with a CO2-charged spray system through 80015 nozzles (l /row) mounted in front of the press wheels. The spray tips were turned to spray across the furrow and calibrated to deliver 5 gpa finished spray. Control of thrips was assessed by randomly selecting 5 plants per plot at 7, 11, 16, 19, 23, 27, 31, and 35 days after emergence (DAE). Plant samples were washed to remove insects. Major pest and/or secondary pest control was initiated in Jun and continued on an “as needed” basis through Aug. Percent open bolls was determined on 4 Sep. Samples of 25 bolls/plot were collected and ginned on a laboratory gin to determine lint percentage for each plot. These data were then used to determine lint yield. The center two rows were mechanically harvested on 30 Sep and 20 Oct using a John Deere spindle-type picker. Yields were converted to lb lint/acre.