Nitrogen Effect on Fine Fescue Fiber and Protein Contents.

Fine fescues (Festuca spp.) are low maintenance grasses that could be more widely used if the traffic tolerance of these species were improved. Fiber and protein affect shoot tensile strength, rigidity and elasticity and thus may have effects on wear tolerance. The objective of this study was to assess the effect of N fertilization on fiber and protein content of fine fescues. The trial was arranged in a 3 x 4 factorial split-plot design with 4 replications. The main plot factor consisted of three fine fescue species (Festuca brevipila R. Tracey ‘Beacon’, F. rubra L. rubra ‘Garnet’, F. rubra L. subsp. fallax (Thuill.) Nyman ‘Rushmore’) seeded in September 2012 on a loam in North Brunswick, NJ. The subplot factor was four levels of N fertilization: 0, 49, 98, and 146 kg ha^-1 yr^-1. Nitrogen fertilizer treatments were applied in four split applications in May, June, August and September during 2015 and 2016. The trial was mowed at 6.4 cm and irrigated to avoid drought stress. Pests were controlled as needed. Turf quality, turf color, chlorophyll contents and normalized difference vegetation index (NDVI) were assessed monthly. Verdure samples were collected before the first N application (May) and after the second (July) and the fourth (October) N application in 2015 and 2016. Verdure samples were used to determine leaf water content, biomass, fiber analysis (total cell wall, hemicellulose, lignocellulose, lignin and cellulose content), and protein content. Better turf quality, darker green leaf color and higher chlorophyll content were observed for fine fescues fertilized with N before symptoms of summer patch disease expressed. Nitrogen fertilization increased leaf water content but had no significant on fiber content of the three fine fescue species. Fiber content differed among the three fine fescue cultivars (Table 29). Beacon had the greatest total cell wall (NDF), lignocellulose (ADF) and lignin (ADL) content while Garnet exhibited the lowest fiber contents. Data on protein content will be presented.