Effects of Cane Density on Floricane Raspberry Assessed Using UAV-Based Multispectral Imaging

This study addresses the role of cane density as a key agronomic factor in floricane raspberry production and explores its relationship with canopy structure assessed using UAV-based multispectral imaging. Although cane density is widely recognized as critical for yield formation, its interaction with remotely sensed vegetation indices remains insufficiently understood. The experiment was conducted in an open-field plantation in eastern Poland using four floricane raspberry cultivars and four cane-density treatments (two to five canes per plant). Yield components were measured throughout the harvest period, and multispectral data were acquired using an unmanned aerial vehicle to derive vegetation indices and assess spatial and temporal canopy variability. Yield per plant and fruit number increased consistently with cane density, while yield per cane decreased, indicating a trade-off between individual cane productivity and total yield. Fruit size remained relatively stable and was primarily influenced by harvest timing. Vegetation indices followed a common seasonal pattern, with moderate and variable responses to cane density. The integration of yield measurements with multispectral data revealed that cane density influences not only productivity but also canopy structure and its spatial uniformity. These findings highlight the potential of combining agronomic practices with remote sensing approaches to support data-driven optimization of raspberry production systems.