S16 - Session O2 - Light detection and ranging (LiDAR) to characterise apple tree canopies

Authors: Nils Siefen *, Ana Maria Vogel, Roy McCormick, Konni Biegert

Precision apple farming requires non-destructive sensor technologies to identify key sources of variation in fruit yield and quality within the orchard so management operations such as thinning, root pruning, pruning, harvesting, storage and marketing to the final consumer can be better targeted and optimised. A high-quality tractor mounted light detection and ranging (LiDAR) scanner (SICK, LDMRS 400001, Düsseldorf, Germany) was used to determine 'Braeburn' tree canopy volumes and estimate the leaf area for individual trees. In addition, a commercial orchard sprayer was fitted with four lower cost SICK LiDAR sensors and used to scan the same trees. An experimental treatment (root pruning) was conducted early in the growing season (June) to reduce tree growth and the LiDAR scans and reference assessments (manual removal and counting of leaves and photocopy scanning to determine leaf area) were made at the end of the growing season. The LiDAR scans were conducted at two speeds 1.5 and 7.0 km/h (standard spraying speed). Field scan data will be compared from both scanners and speeds. The feasibility to use non-destructive assessment of the apple tree canopy characteristics for targeted spray applications, to identify vigorously growing trees for example for targeted root pruning treatments and to match canopy leaf areas with targeted irrigation management will be discussed.