Control of Annual White Grubs in Kentucky Bluegrass, 1982

The experiment was conducted in a lawn in Lincoln, NE (Lancaster Co.). Thatch accumulation was 0.59 - 0.67 in, and temperature at treatment time (Sep 14) was 76.2 F. The grubs were third instars and damage to the turf was evident. The experimental design was a randomized complete block with 3 replicates. Individual plots were 2 × 2 ft. Granular materials were mixed with clay granules and hand shaken onto the plots. Liquid formulations were mixed with water at equivalent rates of 1,530 gal/acre and applied with a hand-held sprinkling can. After all treatments were applied, the entire test was irrigated with an automatic watering system with sufficient water to wet the first 0.5 in of soil. Rainfall during the post-treatment sampling period (Sep 14 - Oct 14) was measurable on Sep 14 (0.25 in), Sep 18 (0.47 in), Sep 29 (0.47 in), Oct 1 (0.50), Oct 3 (0.35 in). Grub populations were sampled at 2 (Sep 30) and 4 (Oct 14) wk post-treatment by cutting a 1 × 2 ft × 2 in deep s trip from each plot on each sampling date with a mechanical sod cutter, and recording the number of live and dead grubs in the sod roll and in a 1 in zone below the soil line. Percent control of each plot was transformed to arcsin prior to AN0VA; untransformed means are presented in the table.