Preemergence Control of Crabgrass in Tall Fescue Using Crew

By Jeffrey Derr, Ph.D., Adam Nichols, Aman Rana Virginia Tech, Hampton Roads AREC

Crabgrass is a summer annual grassy weed that detracts from the appearance of lawns. The color difference along with the surface uniformity differences between tall fescue and crabgrass are an issue for homeowners, parks, and commercial grounds. Crabgrass begins to germinate in mid-March on the eastern side of Virginia and continues through most of the summer. In tall fescue, crabgrass tends to invade in areas where tall fescue is thinned out by brown patch during the hot, humid summer. As an annual, crabgrass can be controlled using preemergence herbicides. Crew contains two common preemergence herbicides, isoxaben, and dithiopyr, but is a granular product that can be applied with a spreader. We tested the preemergence control of crabgrass with Crew versus industry sprayable-formulation standards in a stand of tall fescues.

Crew at 200 lb/A provided excellent preemergence control of crabgrass and at 150 lb/A provided comparable control to the industry standards. Crew provides another excellent option for lawn care operators in an easy-to-use product.