Potato L. Californicus Control, Ellensburg, Washington, 1972

The soil type in the test plot is not known, but it was probably Naches Series, loam, with less than 3% organic matter. Broadcast and sidedress treatments were conducted as separate experi-ments, and each treatment was replicated 4 times in a randomized complete block design. Each plot was 6 rows wide (34 inch apart) and 50 ft long. Each treatment was replicated 4 times in a randomized complete block design. On May 1 and 2, 1972, broadcast applica-tions of granular materials were made with a hand-operated grass seeder, and the Dyfonate EC (40 gal/acre) with a tractor-mounted sprayer, then disced within 1 hr after application. Potatoes were planted on or about May 8. Sidedress applications of granular materials were made on May 22 and 23, using tractor-mounted Gandy applicators; granules were placed in 1 inch bands, 4 inch to each side and level with the potato seed pieces. The plots were rill irrigated. Tuber samples were harvested on October 11 to 16, from the 2 center rows of each plot. Injury (any penetration of a tuber by wireworms) was assessed based on the number of injured tubers per 100 lb. Percentages of injured tubers were transformed to X + 0.5 and analyzed by analysis of variance and Duncan’s new multiple range test.