Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2015
Publication Date: 1/26/2015
Citation: Mahan, J.R., Burke, J.J. 2015. Active management of plant canopy temperature as a tool for modifying plant metabolic activity. American Journal of Plant Sciences. 6:249-259.
Interpretive Summary: Agricultural plants are grown in environments in which temperature changes continuously. These temperature changes affect the way the plant grows. The temperature experienced by the plant over its growing season has many effects on the final plant product. The yield and the quality of the plant products can be improved or diminished depending on the crop and its product. For instance grapes produced for eating are grown differently than grapes for wine production. In this study we constructed and tested an irrigation system that was designed to water the plant in such a way that the plant’s temperature was altered in a predictable and desired manner. It is hoped that such a tool will allow producers to use irrigation as a tool to optimize the quality of plant products.
Technical Abstract: The relationship between a plant and its thermal environment is a major determiner of its growth and development. Since plants grow and develop within continuously variable thermal environments, they are subjected to continuous thermal variation over their life cycle. Transpiration serves to uncouple the temperature of the plant from that of its environment in a manner that reduces the occurrence of high temperature stresses that can limit plant performance. In some agriculturally important plants there are desirable metabolic outcomes that are associated with specific stress events (e.g. wine grapes). In these plants it is often desirable to induce temperature and water stresses of known magnitude and duration at specific points in the growing season. In this study we used a computer-controlled irrigation system that used cotton canopy temperature to control irrigation in greenhouse-grown plants over a 10-day period. The system was designed to irrigate in a manner that altered the canopy temperature relative to specific temperature thresholds (28°,30°,32° and 34°C). The results demonstrate that automated irrigation management based on canopy temperature is capable of altering the temporal pattern of canopy temperature in a desired manner using a feed-back loop. Potential limitations on this action are related to the range of air temperatures, radiation and humidity within the environment.