Seasonal Herbage Accumulation and Nutritive Value of Irrigated 'Tifton 85', Jiggs, and Vaquero Bermudagrasses in Response to Harvest Frequency

Grasses within the Cynodon genus are widely used perennial forages, and 'Tifton 85' (Cynodon spp.) is one of the most popular commercial cultivars. Jiggs and Vaquero are new C. dactylon (L.) Pers. grasses, but there is little information comparing their performance with Tifton 85 under tropical conditions. The objectives were to describe and explain variation in seasonal herbage accumulation (HA) and nutritive value of irrigated Tifton 85, Jiggs, and Vaquero bermudagrasses in response to harvest frequency (14, 28, and 42 d). The trial was performed for 2 yr in Piracicaba, Brazil, on a Kandiudalfic Eutrudox soil. In the warm season, total HA of Jiggs was similar to Tifton 85, and both were more productive than Vaquero. Under the 42-d frequency, Jiggs had greater annual HA than the other grasses (28.5 vs. 23.7 and 20.1 Mg ha(-1), for Tifton 85 and Vaquero, respectively), but when harvested every 28 d, Tifton 85 and Jiggs HA were similar (18.5 Mg ha(-1)). For the 42-d harvest interval in the cool season, Jiggs had the greatest HA (10.2 Mg ha(-1)). Less frequent harvests in both seasons resulted in greater HA. Tifton 85 had a greater proportion of leaves than Jiggs and greater in vitro digestible organic matter (IVDOM) than the other grasses in the warm season. Considering these responses, harvest frequency of Jiggs and Tifton 85 should be similar to 28 d in the warm season, while that of Vaquero should be similar to 42 d. No single harvest management will be appropriate for all Cynodon grasses.