Fig. 2. Standard and cold test germination for seed lots of hybrid F harvested at different developmental stages in 1999 and exposed to one of three treatments (1) unfrozen control, or frozen for 6 h at –6°C using two different rates: (2) fast freeze or (3) slow freeze. Error bars = ± SEM. Physiological maturity occurred at 359 g kg^–1 seed moisture content.