Can Plant Health Sensors Detect Insect Injury and Water Stress in Cotton?

Use of a tractor-mounted plant health sensing system was evaluated in a Cotton Fleahopper/Water Stress experiment arranged in small plots (50 feet by 4 rows) at the Texas A&M AgriLife Research and Extension Center, Corpus Christi, in 2013 and 2014.  The plant health sensing system consisted of an optical sensor, an ultrasonic sensor, a GPS receiver, and a data acquisition unit.  Plant height measures from the ultrasonic sensor readings indicated differences between planting dates and insecticide sprayed and unsprayed treatments, including detection of an interaction between these treatments in 2013 when cotton fleahopper feeding pressure was high. NDVI calculated from the optical sensor readings showed differences between planting dates and cultivars, including detection of an interaction between these treatments, but difference between insecticide sprayed and unsprayed treatments were more difficult to discern.