Response of Seeded and Vegetative Buffalograss [Buchloe Dactyloides (Nutt.)] Cultivars to Nitrogen Fertilization and Simulated Traffic.

There is great interest in buffalograss in California because of its superior avoidance of extreme drought. A study was conducted at the University of California, Riverside in 2013 to evaluate performance of three seeded cultivars (NEBFG 07-01, Sundancer, NEBFG 07-4E) and vegetatively-propagated ‘UC Verde’ fertilized at 10 or 20 g N m^-2 yr^-1, and subjected to traffic (10 soccer games yr^-1 with the Brinkman traffic simulator) or no traffic. Turf was established in 2010 and maintained at 5 cm height of cut. Visual assessment of quality and weed intrusion, and digital image analysis (DIA) were collected monthly from June to November. Weed cover was assessed by DIA using hue and saturation settings from 30 to 65 and from 0 to 100, respectively. Visual assessment of weed cover and DIA was subsequently correlated. ‘UC Verde’ yielded the highest quality (6.3) and the lowest weed cover on the plots (7%). Plots that received higher N had higher turf quality and lower weed cover than those fertilized at the lower rate. Traffic also had negative consequences on turf quality and weed cover.  Correlations between visual quality and DIA were significant for each month and allowed for linear regression analysis. Regression coefficients were also significant during each month, but were never higher than 0.6. Based on our results, ‘UC Verde’ was the only cultivar that could tolerate traffic, regardless of the fertilization regime. No differences were observed among the three seeded cultivars. Our results also suggest that there was a considerable part of variability that cannot be explained by a linear regression model between visual ratings and DIA.