Potato Leafhopper Control in Ohio, 1992

Abstract

Tests were conducted at the OARDC Western Branch Field Station near South Charleston to evaluate the efficacy of 5 insecticides for control of PLH on 2nd and 3rd cuttings of a 3 year old alfalfa stand. Plots were 13.7 X 15.2 m (45 x 50 ft) with 5 replications per treatment in a randomized complete block design. However, the location of 3rd cutting treatments remained the same as that selected for the 2nd cutting. Treatments were applied on 30 Jun to the 2nd cutting and on 11 Aug to the 3rd cutting with a custom built sprayer having a boom length of 4.6 m (15 ft) and flat spray tip nozzles (Teejet 800VS) mounted at 38.1 cm (15 inch) intervals. The system was calibrated to deliver 280.6 liters/ha (30 gal/ acre) at 30 psi at a tractor speed of 5.6 km/hr (3.5 mi/hr). The 2nd cutting treatment was applied when alfalfa stem length was 43.5 cm (17.1 inches) to evaluate control efficacy in a situation where harvest was delayed but stand was susceptible to very heavy PLH feeding activity. The 3rd cutting treatment was applied when stem length was 27 cm (10.6 inches) following harvest of the 2nd cutting. PLH adult abundance was estimated by talcing 10 pendulum sweeps in each plot within 1 day prior to treatments and 2, 7, and 14 DAT. PLH nymph abundance was estimated 7 and 14 DAT when the stage was present in abundance in the untreated plots. Alfalfa stem length was recorded prior to treatments and at 7 and 14 DAT.