Dynamic Classification of Moisture Stress Using Canopy and Leaf Temperature Responses to a Step Changes of Incident Radiation

Environmental conditions affect plant productivity and understanding how plants respond to drought stress can be measured in different ways. This study focused on measuring leaf response time to induced water stress. Leaf response time to a step increase and step decrease in radiation was computed for four species of well-watered and water-stressed plants in a controlled environment. The canopy temperature was measured with an infrared thermometer and a thermal imaging camera. Thermal images were analyzed to determine the average temperature of a selected single, unobstructed leaf at the top of the canopy. Both the canopy response time and the single leaf response time were computed for this study. The response times to a step change of radiation for well-watered plants were generally longer than the response times of water stressed plants. These results show that response time may be used as an indicator of plant water stress