Thrips Control, 1988:

Abstract Onions were direct seeded in single-row beds with 40-inch centers in a Willacy line sandy loam soil at the Texas Agricultural Experiment Station, Weslaco, Tex. Plots measured 10 ft by 2 beds and were bordered by rows of grain sorghum. Ten-foot alleys divided replications. Treatments were replicated 4 times in a randomized complete block design. Plants were treated when thrips levels were greater than 15/plant. Two applications were made at 4-d intervals with a tractor-mounted CO2-powered sprayer, calibrated to deliver 20 gal/acre at 3 mph and 60 psi. Surveys of thrips populations were made at 3 and 7 d after the second application. Prior to application a survey was conducted to determine species of thrips present. Data were summarized and subjected to ANOVA and DMRT for mean separation, in which a log10(x + 1) transformation was used.