Early-season growth and fall forage production by wheat (Triticum aestivum L.) is an important cultivar selection criterion for producers in the southern Great Plains. This requirement results from the use of winter wheat as a source of forage for stocker cattle from early winter to early spring. While differences in fall forage production potential of winter wheat cultivars has been reported, there have been few attempt to identify which physiological growth parameters are most influential in determining fall forage production of wheat. To investigate this topic, rate of canopy closure, extinction coefficient, specific leaf weight, and radiation use efficiency of 18 commonly grown hard red winter wheat cultivars at Stillwater, OK. Neither extinction coefficient nor specific leaf weight had a significant impact on fall wheat forage production. Small differences in rate of canopy closure among wheat cultivars were observed, but differences were not large enough to explain differences in total fall forage production. Radiation use efficiency varied from 1.98 to 2.79 g MJ^-1 among winter wheat cultivars and had the greatest impact on fall wheat forage production. Radiation use efficiency was not well correlated with extinction coefficient, indicating that breeders wishing to maximize forage utilization can select for a more erectophile growth habit without necessarily sacrificing forage production.