Control of Potato Leafhopper on Potatoes Using Reduced Ratesl of Insecticides, 1997

Potatoes were planted 19 May at the University of Minnesota Agricultural Experiment Station, Rosemount, MN. Plant spacing was 36 inches between rows and 12 inches between plants within rows. Treatments were arranged in a RCB design with 3 replications. Plots were 8 rows wide by 40 ft long, separated by 12 ft of al-falfa borders on all sides to enhance PLH population. Thirty-five midplant leaves were sampled from the center four rows of each plot. Pre-treatment counts and treatment applications were made 29 Jul. All treatments were applied with a tractor-mounted Brittonya boom sprayer delivering 45 gpa at 90 psi with 3 nozzles per row. Post-treatment counts of PLH nymphs were made 30 Jul, 24 hours after treatment. Early and late blight were controlled by eight applications of chlorothalonil. Analyses of variance were calculated following transformation of the data using logl0(x).