ON THE BEHAVIOR OF A STRESSED COTTON CANOPY IN A DIRECT AIR STREAM

Reflectance variations of a stressed cotton canopy were conducted in the presence of a fan-generated air stream to investigate the effects of air movement and the resulting temperature changes on remotely-sensed data. The initial drop in reflectance after application of the air stream was found to be greatest in the morning because leaf turgor was at a maximum, enabling leaves on the windward side of the canopy to assume surprisingly stable vertical positions. This transient configuration in the morning was responsible for greater stem displacement (relative to that of the afternoon), because the leaf area normal to the air stream was maximized, thus increasing the capacity of the canopy to trap light.