Impact of Soil Saturation on the Performance of At-Planting Insecticides for Thrips Control, 1997

Abstract

Abstract Plots were replicated four times in a RCB design with a split-plot arrangement of treatments. Plots were 4 rows wide (40-inch spacing) X 45 ft. ‘Stoneville 474’ cotton seed were planted on a Sharkey clay soil on 5 May which were planted with a John Deere 7100 series planter which was equipped with 10 inch seed cones mounted to replace the seed hoppers. The seeding rate was 4 seed/row ft. Granular in-furrow treatments were applied with 8 inch belt-cone applications mounted to replace the standard granular applicators. In-furrow spray treatments were applied with a CO2-charged spray system through 25015 nozzles (1/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. Irrigation treatments consisted of no irrigation and the equivalent of 4 inches of rainfall 4 days after emergence, simulating excess rainfall and saturated soil conditions. Control of thrips was assessed by randomly selecting 5 plants per plot 7, 11, 15, 22, 25, 30, and 34 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. The two center rows per plot were mechanically harvested on 19 Oct using a John Deere spindle-type picker. Yields were converted to lb seedcotton/acre.