EVALUATION OF POACEAE SPECIES AND SUPPRESSION APPLICATION METHODS FOR PERENNIAL GROUNDCOVER IN CORN

Intensive grain production aims to provide food security but has depleted once-perennialized land. Perennial groundcover (PGC) offers ecosystem services to intensive annual corn (Zea mays L.) production. In past research conducted in the U.S. Midwest, Kentucky bluegrass (Poa pratensis L.) has been the standard PGC species. However, it is slow growing and difficult to suppress. To characterize the PGC system in the midsouth, two separate field trials in Lexington, Kentucky, were conducted to (i) compare the first-year establishment of alternative cool-season species to Kentucky bluegrass, with and without a spring-applied broadleaf herbicide, and their impact on corn grain yield, and (ii) evaluate the effects of spray pattern and carrier volume on glufosinate herbicide coverage and resulting efficacy of Kentucky bluegrass suppression. Kentucky bluegrass remains a more viable option for corn production than the alternatives evaluated, and the use of a spring-applied herbicide did not improve first-year grass establishment. Generally, increased carrier volume used with a dual fan spray pattern improved coverage but did not consistently influence suppression efficacy. These findings contribute to the refinement of PGC systems, helping optimize species selection and suppression application methods for improved integration into annual cropping systems in Kentucky.