Fig. 3. Effect of air temperatures of –2.5, –5.0, or –7.5°C and of insulation of Cone-tainers on the duration of exposure to air and soil temperatures of 0, –1, or –2.0°C of Italian ryegrass seedlings: AIR = air temperature indicated by probes positioned adjacent to seedling leaves, EXP = soil temperature indicated by probes inserted into soil in an uninsulated Cone-tainer, INS = soil temperature indicated by probes inserted into soil in a Cone-tainer insulated in a block of polystyrene.