Impact of Soil Saturation on the Performance of At-Planting Insecticides, 1996

Abstract

Abstract Plots were replicated four times in a split plot design and were four rows (40 inch spacing) X45 ft. Stoneville LA 887 cotton seed of the same seed lot was planted on 6 May on a Sharkey clay soil which was fertilized with 90 lb N/acre. Cotton seed was 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 applicators 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 on 20, 24, 28, and 31 May and 5 and 9 Jun. Plant samples were processed by using whole plant washing procedures to remove insects. Major pest and/or secondary pest control was initiated in Jun and continued on an “as needed” basis through Aug. Plots were harvested on 7 Oct. The two center rows were mechanically harvested using a John Deere spindle type picker. Yields were converted to lbs seed cotton/acre.