Comparative yield and nutritive value of atra paspalum and dwarf elephantgrass

'Suerte' atra paspalum (Paspalum atratum Swallen) and 'Mott' dwarf elephant grass (Pennisetum purpureum Schum.) are perennial forage grasses that are s imilar in growth habit. Mott is high in nutritive value and provides a stan dard against which Suerte, a new cultivar, can be compared. Both grasses re ceived 0 to 336 kg N ha(-1) over 2 yr (0 to 224 in Year 3), and were clippe d every 21, 42, and 63 d from March to November (252 d). Annual dry matter (DM) yield declined linearly over 3 yr (10.7 to 2.8 Mg ha(-1)) for Mott and declined quadratically for Suerte (9.3 to 6.2 Mg ha(-1)). Annual yield dep ended on a year x N interaction, with yield increasing linearly (but at dif ferent rates) over levels of N. Annual yield of both grasses increased line arly as clipping interval increased. Annual yield depended on the N x clipp ing interval interaction in which yield within each interval increased line arly over level of N, but more DEA was produced kg(-1) of N as interval inc reased. Mott produced more DM in the cooler, dry March to May period, while Suerte produced most of its DM in the wet July to September period. Tiller s of Mott remained erect, while tillers of Suerte became decumbent with fre quent clipping. Although both grasses are almost entirely leaf throughout t he year, Mott had greater crude protein and in vitro organic matter digesti bility (IVOMD) than Suerte at every sample date. Suerte declined faster in nutritive value and reached lower levels in August than Mott. While Suerte is easily established from seed and Mott is difficult to establish vegetati vely, Mott is a superior grass nutritionally. However, it is not as persist ent as Suerte.