Effect of Date of Application on Efficacy of Tempo and Merit Against Annual Bluegrass Weevil on Golf Course Fairway, 1997

Several combinations of cyfluthrin (Tempo 20 WP) and imidacloprid (Merit) were applied to golf course fairway turf in the spring of 1997 to determine efficacy against annual bluegrass weevil. This test was conducted at two sites, Sleepy Hollow Country Club (Scar-borough, NY) and Fairview Country Club (Greenwich, CT). At Sleepy Hollow, applications were made on 21 Apr (sunny, calm, air temp 53° F, soil temp at 2 in 55° F), 13 May (high overcast, calm, air temp 51° F, soil temp 50° F), or 22 May (sunny, calm, air temp 56° F, soil temp 48° F). Soil pH was 6.4, buffered pH 6.8, CEC 20.3 Meq/100 g. At Fairview, applications were made on 29 Apr (sunny, light breeze, air temp 46° F, soil temp 42° F) or 13 May (sunny, calm, air temp 55° F, soil temp 51° F). SoilpH was 6.3, buffered pH 6.8, CEC 14.5 Meq/100 g. Treatment plots were 6 ft by 6 ft, replicated 5 times, and arranged in a CRB. All applications were applied with a watering can using 3 liters of water per plot. Plots were watered in with 0.1 to 0.2 in irrigation within 1 hr of application. Product efficacy was evaluated on 23 Jun (Sleepy Hollow) or 11 Jun (Fairview) by removing 12 cores, 1.83 inches diam each from near the center of each plot. Cores were transported to Amherst, MA, where they were broken apart manually and inspected under 10 X magnification. Insect counts were recorded for 3 cores at a time (4 observations per replication, 20 total observations).