Spatial Variability of Turfgrass Stress Responses in Golf Course Fairways using Drone Imagery

Advancements in technology have enhanced the ability of land managers to evaluate plant stress using vegetation indices. Vegetation indices are a valuable tool in evaluating plant systems for stress that may include water deficit, nutrient deficiency, pest development, or abiotic stress. Managers then scout areas of high stress recognition to identify the underlying cause of the stress. These techniques have not been thoroughly evaluated for potential application in turfgrass systems. The integration of remote sensing technology in precision turfgrass management (PTM) offers new avenues for monitoring and managing drought stress in golf course fairways. The objective of this study was to utilize small unmanned aerial systems (sUAS) equipped with multispectral cameras to capture normalized difference vegetation index (NDVI), enabling the detection of drought-stressed areas in fairway turfgrass. Two unique near infrared (NIR) bands (850 and 970 nm) were used in NDVI determination with 850 nm being a standard NIR band and 970 nm being more specifically targeted at plant water stress. The 970 nm band resulted in higher NDVI calculated across nearly all flights at two golf courses. There were significant differences in NDVI observed across flight dates. Moreover, 10-meter parcels of each golf course fairway notated areas of lower or higher plant stress. High stress zones within each fairway can then be evaluated more closely with the golf course management team to diagnose the primary stress and determine corrective actions to improve plant health. These results are critically important because they demonstrate techniques to quickly discern areas of plant stress and limit the need for comparable management inputs over the entire fairway. This alone can have a significant impact on golf course management because targeted solutions will require less time, resources, and labor to apply. Furthermore, reducing inputs while still maintaining consistent plant health and playability standards enhances sustainability of golf course management.