Establishment and Allelopathic Potential of Centipedegrass (Eremochloa ophiuroides (Munro) Hack.) in Utility Turf Areas.

Abstract

Field and greenhouse experiments were conducted to 1) evaluate the safety and effectiveness of weed control treatments while establishing seeded centipedegrass and 2) determine the allelopathic potential of centipedegrass. Centipedegrass tolerance to treatments applied at seeding and early postemergent was evaluated. Atrazine, simazine, or low rates of imazapic did not reduce centipedegrass ground cover compared to the control while select rates of sulfometuron and all rates of metsulfuron were injurious to centipedegrass when applied at seeding. All rates of imazapic, sulfometuron, atrazine, or simazine applied 6 weeks after seeding (WAS) (one-leaf to one-tiller growth stage) caused less than 15% phytotoxicity, while chlorsulfuron + mefluidide, or metsulfuron caused 16 to 83% phytotoxicity 56 DAT. When large crabgrass and centipedegrass were seeded together, large crabgrass emergence was reduced (48%) by atrazine applied at seeding compared to the control (89%). In atrazine treated flats, centipedegrass tiller production and cover were greater due to reduced interspecific competition from large crabgrass. These data indicate that where large crabgrass is present, centipedegrass can be established more quickly if appropriate herbicides are used at seeding or shortly thereafter.

Germination and growth of indicator species were evaluated in response to treatment with soil leachates, leaf debris, and aqueous leaf extracts of centipedegrass. Incorporated centipedegrass leaf debris did not reduce lettuce germination, shoot weight, or root weight as compared to the control. However, shoot and root dry weight of radish were reduced with increasing rates of centipedegrass leaf debris. These data do not conclusively demonstrate centipedegrass has widespread allelopathic activity; however significant reductions in shoot and root dry weight of radish with increasing debris rate demonstrates a pattern of inhibition of one species against another fulfilling a requirement of allelopathic interactions.