Fig. 1. Root concentrations of total N (A, B), total amino acids (C, D), and total soluble proteins (E, F) of two alfalfa cultivars (AC Caribou and WL 225) harvested twice or three times with a third harvest taken at 400, 500, or 600 GDD after the second harvest. Concentrations were measured at each harvest date for the corresponding harvest treatments (Harvests): on 7 Aug. 1997 for plants harvested twice, and on 8 Sept., 17 Sept., or 7 Oct. 1997 for plants harvested at 400, 500, or 600 GDD after the second harvest, respectively. Concentrations were also measured for all harvest treatments on 10 Nov. 1997, 12 Jan. 1998, and 11 Mar. 1998. Vertical bars indicate SEM for each sampling date, except for soluble proteins since there was no replicate.