In terms of nutritive value, CP of bahiagrass was consistently lower at all locations under the extended daylength treatment. Lower CP of bahiagrass growing under extended daylength com- pared to those growing under natural daylength plots is at least partially accounted for by a dilution effect due to the greater DM harvested under extended light. These results corroborate pre- vious results with bahiagrass at higher latitude (Sinclair et al., 2003). The CP in either case was not marginal and was above the minimum critical levels (60–80 g kg−1) required for livestock production and proper rumen-bacteria functioning (Humphreys, 1991; Van Soest, 1994). In vitro digestible organic matter was only affected by extended daylength at St. Croix. The onset of plant reproduction has been recognized as a crucial factor in C4 grass herbage quality decline