What is the purpose of reducing apical dominance in trees during pruning?

Reducing apical dominance in trees during pruning primarily serves to stimulate growth from lateral buds. Apical dominance refers to the phenomenon where the main central stem grows more vigorously than the side branches due to the influence of hormones, particularly auxins, produced at the apex of the plant. When pruning is applied to cut back the leader or central stem, this can diminish the hormonal control that suppresses lateral bud growth.

As a result, lateral buds that were previously held back begin to grow more freely, leading to a bushier and fuller appearance for the tree. This strategy is especially useful in managing the shape and density of trees, encouraging a more balanced growth that can enhance the tree's overall health and aesthetic appeal. It allows for a diversification of growth that can support a more robust structure, leading to better resistance against wind and other external factors.