Overseeding Bentgrass Species into Existing Stands of Annual Bluegrass

Abstract

Field trials were conducted in 2000 and 2001 to determine the potential of converting pure stands of annual bluegrass [ Poa annua L. spp . reptans (Hauskins) Timm.], maintained at a 3.2-mm height, to bentgrass ( Agrostis spp . ). Parameters evaluated included three overseeding dates and four cultivars from two bentgrass species. Overseeding dates were 1 July, 18 Aug., and 18 Sept. 2000 and 27 June, 17 Aug., and 17 Sept. 2001. Three creeping bentgrass ( A. stolonifera L.) cultivars (`Penncross', `L-93', and `Penn A-4') and one velvet bentgrass ( A. canina L.) cultivar (`SR7200') were evaluated. Initial bentgrass establishment was evident across all seeding dates and cultivars in October of the year of overseeding. However, the 1 July 2000 and 27 June 2001 overseeding dates had the highest levels of bentgrass coverage 12 months after overseeding across all cultivars except `Penncross'. Coverage of `Penn A-4' and `L-93' increased to 72% in the 1 July 2000 overseeding date, 24 months after the initial overseeding. When overseeded in early summer, velvet bentgrass `SR7200' showed the greatest potential for establishment with annual bluegrass. `SR7200' and creeping bentgrass cultivars `Penn A-4' and `L-93' exhibited the greatest potential for long-term competitiveness with annual bluegrass, while `Penncross' exhibited the lowest potential.