Experiments were conducted to evaluate safety and effectiveness of herbicides during establishment of seeded centipedegrass. Centipedegrass tolerance to herbicides was evaluated at seeding and early postemergence. Imazapic at 105 g ai/ha, sulfometuron at 53 g ai/ha, or metsulfuron at 21 or 42 g ai/ha applied at seeding reduced centipedegrass ground cover compared with the nontreated. Imazapic at 18 or 35 g/ha or applications of atrazine or simazine at seeding did not reduce centipedegrass ground cover compared with the nontreated. Applications of chlorsulfuron plus mefluidide (7 140 g ai/ha) or metsulfuron at 21 or 42 g/ha applied 6 wk after seeding (WAS) centipedegrass (one-leaf to one-tiller growth stage) caused 20, 16, and 83% phytotoxicity, respectively, 56 d after treatment (DAT). Imazapic, sulfometuron, atrazine, or simazine applied 6 WAS caused <15% phytotoxicity 56 DAT. When large crabgrass and centipedegrass were seeded together, large crabgrass emergence was reduced 41% when atrazine (1,100 g ai/ha) was applied at seeding. Centipedegrass tiller production was reduced with increasing amounts of crabgrass. However, centipedegrass tiller production and ground cover were higher when atrazine was applied because of reduced interspecific interference from large crabgrass. These data indicate that centipedegrass can be established more quickly if appropriate herbicides are used at seeding or shortly after seeding.
Nomenclature: Atrazine; chlorsulfuron; imazapic; mefluidide; metsulfuron; simazine; sulfometuron; large crabgrass, Digitaria sanguinalis (L.) Scop. #3 DIGSA; centipedegrass, Eremochloa ophiuroides (Munro) Hack.
Additional index words: Atrazine, chlorsulfuron, Digitaria sanguinalis, herbicide tolerance, imazapic, interference, large crabgrass, mefluidide, metsulfuron, PGR tolerance, simazine.
Abbreviations: DAS, days after seeding; DAT, days after treatment; PGR, plant growth regulator; WAS, weeks after seeding.