An aerial imagery approach to differentiating bermudagrasses ( Cynodon spp.) and Japanese lawngrass ( Zoysia japonica ) using dew retention patterns

Bermudagrasses ( Cynodon Rich. species) easily contaminate fields of zoysiagrasses ( Zoysia Willd. species) through vegetative propagules and seeds, and once established, can be hard to eradicate. Zoysiagrasses and bermudagrasses vary in color, texture, and canopy architecture; infestations can be visually identified when dew is present. Field research conducted in 2024 quantified the volume of dew retained in Tifway hybrid bermudagrass ( Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy) and Meyer Japanese lawngrass ( Zoysia japonica Steud.) canopies. The hybrid bermudagrass canopy held a greater volume of dew than Japanese lawngrass at all collection times between sunrise and 150 min after sunrise. Aerial imagery was collected from three sites comprising varying degrees of contamination of bermudagrasses in Japanese lawngrass to test the effectiveness of an artificial intelligence‐based, supervised classification tool (Magic selection tool in PIX4Dfields) in delineating bermudagrasses from Japanese lawngrass. The Magic selection tool's ability to distinguish bermudagrasses from Japanese lawngrass depended on the density of the turfgrass stand, background soil color, presence of other grasses, presence of clippings, and dew volume. Based on dew volume, the ideal time to scout fields for contamination of bermudagrasses is within 90 min of sunrise and when dense stands of both grasses are present.