Colorado Potato Beetle Control with Foliar Sprays of Conventional and Biorational Insecticides, 1992

Experimental plots were established on the UI Research and Extension Center, Caldwell, Idaho. Potatoes were planted 2 Apr and irrigated by solid set sprinkler. The soil type is Greenleaf-Owyhee silt loam. Ten treatments and one untreated check plot were replicated four times in a randomized complete block design. Individual treatment plots were 4 rows (36 inch row spacing) wide by 25 ft long with 5 ft alleyways separating the plots. Applications were made as a broadcast spray using a CO2 pressurized backpack sprayer. Twenty gal of finished spray were applied (30 psi, four, 10X hollow cone nozzles) to all plots. Pre-treatment counts of all beetle stages were made and the first insecticide treatments were applied on 5 Jun. A second application of M-Trak, Kryocide, Bittersweet (KPT), and Tri-Gard was made on 17 Jun. A third application was made of the previously mentioned treatments on 13 Jul for control of the second generation. On a weekly basis, egg masses, larvae and adult beetles were counted and percent defoliation were estimated from whole plant inspections of the center five hills of the center two plot rows. Larval stages were separated into small (1-2 instar) and large (3—4 instar). Data were analyzed using ANOVA and LSD’s.