Sprinkler Irrigation System Applied Insecticides Control Colorado Potato Beetle, 1978

‘Russet Burbank’ potato seed pieces were planted 10-inches apart in 36-inch rows in silt loam soil on May 4. Plots were arranged in randomized blocks of 5 treatments and 5 replications. Four sprinkler heads irrigated 14 rows 40 feet long. The plots were separated by a 60 foot border zone. Beetles were allowed to invade and multiply naturally. One and six tenths inches of water was applied at the rate of 0.20 inches per hour. On Jul 28 ‘78, two insecticides, Imidan 50W (2 lbs ai/A) and Sevimol (1 lb ai/A) were injected into the irrigation system at the beginning of the last half hour of an 8 hour irrigation set and applied to the plots. Both chemicals were also applied at the same rate with a ground-driven sprayer. Adult and larval beetle counts were made 24 hours after application by counting dead and live beetles and larvae found on and beneath three plants in each plot (Table 1). Seven days following treatment, beetles observed on 40 feet of row were recorded (Table 2).