Effect of hollow‐tine cultivation on crabgrass infestation in cool‐season turf

Abstract Hollow‐tine cultivation is a common management practice in cool‐season turfgrass lawns. Research examining the effect of hollow‐tine cultivation on annual crabgrass ( Digitaria spp.) infestations in the absence of preemergence herbicides is limited. Multi‐year experiments were conducted on Kentucky bluegrass ( Poa pratensis L.) and tall fescue [ Lolium arundinaceum  (Schreb.) Darbysh.] monostands at the Rutgers University Horticulture Research Farm No. 2 in North Brunswick, NJ to evaluate the effect of hollow‐tine cultivation in early spring, late spring, and autumn on crabgrass infestations. Herbicides to control crabgrass were not applied at any time during the experiments. These monostands were maintained as simulated lawns; mowing, irrigation, fertilizer, fungicide, and insecticide inputs were provided to maintain high turfgrass density. Crabgrass cover was evaluated in late summer each year. In the tall fescue experiment, hollow‐tine cultivation treatments did not affect crabgrass cover. However, in the third year of the tall fescue experiment, a non‐significant trend ( P = .08) emerged in which early and late spring cultivation treatments resulted in more crabgrass cover (30 and 35%, respectively) than autumn (24%) and no cultivation (26%). A similar non‐significant trend ( P = .056) was observed only during the first year the Kentucky bluegrass experiment as both spring cultivation treatments increased crabgrass cover. This research indicates hollow‐tine cultivation in the springtime does not appreciably increase crabgrass infestations in Kentucky bluegrass or tall fescue in the absence of preemergence herbicides.