Consecutive monitoring method for pecan orchards and discovery of a mysterious circle in a pecan orchard with UAV

In this study, we established consecutive monitoring methods using UAV in pecan orchards of 64 ha each, in San Simon, Arizona, USA. Activity monitoring, tree height map creation and ground surface temperature analysis of trees by UAV with near infrared (NIR)/TIR camera were conducted for pecan orchards in San Simon, Arizona, USA. Using established continuous monitoring methods, the UAV images of a 3-year-old pecan orchard showed circular traces of alfalfa cultivation prior to installation of pivot irrigation that was previously not observed. Tree growth measurements was compared to the trees planted inside and outside of the circle. Growth and tree health activity was found to be better when the trees were outside of the circle.