Modifying Apple Tree Canopies for Improved Production Efficiency

Canopy development in perennial crops has a seasonal and a lifetime developmental pattern. The sum of development over individual seasons results in the final canopy dimensions and form. In apple, there is a natural progression from a single-shoot tree toward the tall (10 m), umbrella-shaped tree (Fig. There are many disadvantages to this large umbrella-shaped tree: 1) it is difficult to spray, prune, and hand-harvest; 2) it has poor distribution of light throughout the canopy; and 3) it has a low early life light interception, leaf area index, and fraction of land covered by canopy, leading to delayed cropping. These disadvantages have resulted in widespread efforts to reduce tree size, increase tree density, accelerate canopy and yield development, and improve canopy form to overcome the limitations of the large tree.