Infrared Thermography as a Means of Assessing Seedling Quality

The possibility of using infrared thermography as seedling vitality test before planting was investigated. The temperature of seedlings of Scots pine and Norway spruce was determined in the laboratory before planting using the AGA Thermovision System. It was found that the field performance conformed to the IR measurements of the seedlings. The "cold" (high-transpiring) seedlings performed better than the "warm" (low-transpiring) ones. Some of the measurement problems discussed concern illumination and the interpretation of the thermograms because of the small size of conifer needles. The IR measurements might be a tool in a future system for grading seedlings.