Fig. 2. Root dry weight (A, B) and shoot dry weight (C, D) of two alfalfa cultivars (AC Caribou and WL 225) harvested twice or three times with a fall harvest taken at 400, 500, or 600 GDD after the second harvest. Root DW was measured at each harvest date for the corresponding harvest treatment (Harvests): on 7 Aug. 1997 for plants harvested twice, on 8 Sept., 17 Sept., or 7 Oct. 1997 for plants harvested respectively at 400, 500, or 600 GDD after the second harvest. Root DW was also measured on three other occasions for all harvest treatments on 10 Nov. 1997, 12 Jan. 1998, and 11 Mar. 1998. Shoot DW was measured on 2 Dec. 1997, 4 Feb. 1998, and 2 Apr. 1998 after 3-wk regrowth periods initiated respectively on 10 Nov. 1997, 12 Jan. 1998, and 11 Mar. 1998. Vertical bars indicate SEM for each sampling date.