Changes in a crop canopy's temperature may now give scientists a complete picture of how much water stress plants are experiencing during drought, says USDA's Agricultural Research Service (ARS).

Researchers have developed an unobtrusive tracking system that uses thermal sensors to remotely monitor canopy water stress and temperature. The system can be rapidly deployed and positioned at various levels, measuring individual leaves or entire canopy elements.

ARS says that changes in canopy temperature may be a more reliable indicator of water stress because canopy temperature rises as water stress increases. Results can be used to help schedule irrigation.