Establishment Fertility of Velvet and Creeping Bentgrass Fairways.

Nitrogen fertility requirements of velvet bentgrass (Agrostis canina L., VBG) during fairway establishment have not been investigated. This study was conducted to compare the N fertility requirement of VBG to creeping bentgrass (Agrostis stolonifera L., CBG) for fairway establishment. Four N rates (0, 49, 146 and 293 kg ha^-1, six equal applications in twelve weeks) were tested on two cultivars of both bentgrass species (‘Memorial’ CBG, ‘Penncross’ CBG, ‘SR7200’ VBG, and ‘Vesper’ VBG), planted on silt loam soils in Minnesota and Wisconsin during summer and fall 2009. Treatments were arranged in a randomized strip-strip plot design with four replications. Vesper established slower than Penncross through week 4 or 11, depending on location, after which time all bentgrasses had cover approaching 100%. Turf cover was directly related to increasing N rate for the first 9 weeks after seeding (WAS).  After 9 WAS, as mean turf cover approached 90% or better, N rate had marginal effects on percent cover. While all cultivars showed acceptable quality near trial end, CBG cultivars had better quality than VBG cultivars in Wisconsin. In Minnesota, Memorial and SR7200 had better quality than Penncross and Vesper. The two greatest N rates provided similarly acceptable quality by about 8 WAS in both locations. The 49 kg ha^-1 N rate provided acceptable quality about 11 WAS while 0 kg ha^-1 N never provided acceptable quality. Velvet bentgrass and CBG seem to have similar N requirements during fairway establishment.