Evaluation of Foliar Treatments for Potato Leafhopper on Alfalfa, 1996

A study to evaluate the efficacy of 5 foliar insecticide treatments to control PLH was conducted on second cutting alfalfa at the OARDC Western Branch Station near South Charleston, OH. Plots were 30 X 50 ft with four replications in a RCBD. Treatments were applied 21 Jun with a custom built sprayer having a boom length of 15 ft and flat spray tip nozzles (TeeJet 8003VS) mounted at 15 inch intervals. The system was calibrated to deliver 25 gpa at 35 psi at a tractor speed of 3 mph. Abundance of PLH adults and nymphs was estimated prior to treatment and 7, 14 and 21 DAT by taking 10 pendulum sweeps per plot. Alfalfa stem length was recorded prior to treatment and at 21 DAT to determine stem growth per treatment. Dry weight yield was determined from harvest of two 3.5 ft X 50 ft swaths taken with a custom built plot harvester with a flail cutter.