Preventive Suppression of White Grubs with Grubex and Mach-2 2.5 G, 1997

The turfgrass area, located in Lancaster County, PA, consisted primarily of Kentucky bluegrass (20%), annual bluegrass (10%), and perennial ryegrass (60%). Treatment plots were 8 X 6 ft, arranged in a RCB design and replicated 3 times. Granular formulations were applied with a hand-held shaker and mixed with fine top dressing sand to facilitate product distribution. At treatment time (14 Jul) the following soil and environmental conditions existed: air temperature, 94° F; soil temperature at 1-inch depth, 74° F; soil temperature at 2-inch, 74° F; RH, 86%; amount of thatch, 0.375-0.5 inch; soil textural class, silt loam; soil particle size analysis: % sand, 14.2%, silt, 65.7; % clay, 20.1; organic matter, 5.5%; soil percent water content (percent by weight), 18.0; water pH, 7.0; soil pH, 6.0; application time, mid-morning; and skies partly sunny. Immediately after treatment select treatments were irrigated in with 0.25 inch of water. The entire experimental area was irrigated in 24 hr later with 0.25 inch of water. Post-treatment counts were made on 29 Sep. Three ft2 sod samples were randomly taken from each replicate, and the total number of JB and AGB grubs/ft2 was recorded.