Soil Temperature Mediated Seedling Emergence and Field Establishment in Bentgrass Species and Cultivars during Spring in the Northeastern United States

Abstract

Reestablishment of damaged golf greens and fairways planted to creeping bentgrass (Agrostis stolonifera), colonial bentgrass (A. capillaris), and velvet bentgrass (A. canina) is a common practice following winter injuries. Identifying bentgrass species (Agrostis sp.) and cultivars with the potential to establish under low soil temperatures would be beneficial to achieving more mature stands earlier in the spring. Twelve bentgrass cultivars, including seven cultivars of creeping bentgrass (007, 13-M, Declaration, L-93, Memorial, Penncross, and T-1), two colonial bentgrass cultivars (Capri and Tiger II), and three velvet bentgrass cultivars (Greenwich, SR-7200, and Villa), along with ‘Barbeta’ perennial ryegrass (Lolium perenne) were evaluated for grass cover in the field during early spring. Bentgrass species and cultivars were seeded in the field at the same seed count per unit area. Soil temperatures were monitored in unseeded check plots from initial planting date on 8 Apr. to termination on 29 May 2013. Soil temperatures increased linearly during the 52-day experimental period from 4.7 to 23.5 °C. All species and cultivars emerged at ≈10 °C soil temperature. Bentgrass species and cultivars varied only 2 to 3 days in their initial seedling emergence, while days varied among bentgrasses from 5.5 days (to 10% cover) to 8.6 days (to 90% cover). All velvet bentgrass cultivars required higher soil temperatures (13.6 °C) and more time (26 days) following initial seedling emergence to establish to 90% cover in the early spring. Creeping bentgrass cultivars 007, 13-M, and Memorial, along with colonial bentgrass cultivars Capri and Tiger II, were statistically equal to ‘Barbeta’ perennial ryegrass in their capacity after seedling emergence to achieve faster cover at lower soil temperatures. Heavier (larger) bentgrass seed was associated with faster cover during the early stages of establishment, but seed size was uncorrelated with establishment during later stages from 50% to 90% cover.