The effect of nitrogen fertility on growth and quality of Agrostis canina L. and Agrostis stolonifera L. putting green turf

Creeping bentgrass (Agrostis stolonifera L.) is the most widely used putting green turf in Ontario, however, substantial fungicide and nitrogen inputs are required for its maintenance. Velvet bentgrass (Agrostis canina L.) is a potential alternative to creeping bentgrass; it is disease resistant and may require limited nitrogen inputs. Establishment requirements for velvet bentgrass were determined in the greenhouse, and were compared with creeping bentgrass. In addition, a field study was conducted on established velvet and creeping bentgrass putting greens; nitrogen rate and foliar versus granular application type were examined. At establishment, both velvet and creeping bentgrass maintained high quality with a weekly nitrogen regime of 0.048-0.096kg N/100m²; root production and turfgrass quality were significantly reduced above this threshold. In the field, velvet bentgrass produced optimal color and quality at a nitrogen rate equivalent to 0.25kg N/100m²/year whereas creeping bentgrass produced best color and quality between a 1.0-2.0kg N/100m² yearly equivalent.