| Abstrakt: |
Bermudagrass (Cynodon dactylon) has been the most popular warm-season perennial grass for hay production and pastures in the southern United States for several decades. It persists on sandy, acidic soils, and N fertilization increases yields. Many new cultivars thrive in the United States and are being established in South America and other tropical environments. Hybrid bermudagrasses, including ‘Coastal,’ released in 1943, are sterile and require establishment from roots and rhizomes, which may increase establishment costs. Vigorous hybrid cultivars may be established using spring top-growth cut at advanced maturity and planted in moist soils. Seeded bermudagrasses have been developed, but few compare with hybrid cultivars, including ‘Tifton 44,’ ‘Tifton 78,’ ‘Midland,’ and ‘Tifton 85,’ for yield, persistence, or quality. Tifton 85 offers hay production potential in the establishment year, whereas most cultivars do not produce enough forage for hay production or heavy grazing until the 2nd yr. After 8 yr, Tifton 85 has increased acceptance and popularity among hay and cattle producers in the United States, and more than 1 × 10** ha have been planted in Brazil. Dry matter yield and forage digestibility have been consistently higher for Tifton 85 than for Coastal and other cultivars, which allows increased stocking rates and greater gain/hectare. Tifton 85 hays have consistently had higher in vitro and in vivo digestibility than Coastal or Tifton 78 hays, even when NDF of the Tifton 85 hay was above 70%. Recent experiments confirmed lower concentrations of ether-linked ferulic acid in Tifton 85 than in Coastal forage, which explains the higher digestibility of Tifton 85 than of Coastal hays. Dairy research indicated that during cool weather, comparable milk yields occurred when Tifton 85 hay was substituted for alfalfa hay in a total mixed ration. In tropical countries ‘Coastcross-1’ and Tifton 85 have been rotationally grazed by dairy cows. Bermudagrasses will continue to be primary perennial grasses for much of the southern United States, and research efforts may provide cultivars with more digestible fiber, greater cold tolerance, and wider adaptability for hay production and grazing for beef and dairy cattle. |
