Potato Leafhopper Control and Potato Yields, 10-Day Interval Spray Program, 1978

Two-row, 50-foot plots with rows 36 inches apart were planted with “B-size” certified seed of the ‘Superior’ cultivar at the University of Wisconsin Research Farm, Arlington, Wl, on May 10‘78. Treatments consisted of 4 replicates in a randomized complete block design. Treatments were applied by a tractor-drawn, 18-foot-boom sprayer delivering 60 gallons of spray per acre. Sprays were applied on Jul 9, 20, 31, Aug 10, and 20. The soil type was Piano silt loam (sand 12%, silt 70%, and clay 18%) with O. M. 30 tons per acre and pH 6.0. Rainfall between planting on May TO and vine killing on Aug 28 was 20.02 inches. Yields were taken on Sep 2. Insect counts were taken with a 15-inch-diameter sweep net.