PRODUCTIVITY AND QUALITY OF BERMUDAGRASS IN A COOL TEMPERATE ENVIRONMENT

In temperate environments a warm-season species is needed to provide forage during summer when the growth rate of cool-season forages is low. Management data for warm-season pasture is limited for the Appalachian region. A bermudagrass [Cynodon dactylon (L.) Pers.] selection RS1, has been identified which is capable of growth and persistence in areas where other cultivars of the species winterkill. A field study was conducted to determine RS1 bermudagrass productivity and quality as affected by a split application of 60, 120, 240, or 360 kg N ha-1 and a 2-, 4-, or 6-wk delay of initial harvest on a fine-loamy, mixed, mesic, Typic Hapludult (Gilpin) soil. Treatments were replicated four times in the field, and the study was conducted for 2 yr. Delaying initial harvest significantly increased yield in both years to more than 8 Mg ha-1 when 360 kg N ha-1 yr-1 was applied. Herbage yields typically ranged between 3 and 6 Mg ha-1 and would contribute substantially to forage requirements in mid-summer in the region. Increased N resulted in higher herbage yield regardless of harvest delay regime. Herbage yields were about 25% less in 1989 than in 1988 and could be due in part to cool and wet conditions in 1989, compared to a hot, dry 1988 growing season. Bermudagrass in vitro dry matter digestibility and crude protein declined with delayed initial harvest (maturity), increased following the mid-season N application, and continued to decline into late summer. Season average quality was not affected by initial harvest delay. Bermudagrass (RS1) will persist and respond to N fertilizer and defoliation management in cool, temperate environments and promises to be a useful component in forage-based animal production systems in the region.