Robotic pruning of apple trees is a challenging task because the crowded and overlapped branches result in narrow spaces for maneuvering the robot inside the canopy ( He and Schupp, 2018 Zahid et al., 2021b). A few studies have reported the development of pruning robots for different crops such as apple ( Zahid et al., 2020a, b), grape, and cherry. Robotic pruning is a selective branch operation that can produce accurate cuts using an end-effector tool attached to the robotic arm ( Lehnert, 2012). A few studies have reported mechanical pruning or hedging of tree fruits ( Krueger et al., 2013), but these operations are less useful for apple trees ( He and Schupp, 2018 Zahid et al., 2021a) because they can result in unwanted vegetative growth. To deal with decreasing labor availability and higher associated costs, alternate solutions are needed.

Manual pruning of apple trees is one of the most labor-intensive operations, requiring ≈80 to 120 h⋅ha −1 of labor ( Mika et al., 2016) and accounting for 20% of the total labor costs ( Crassweller et al., 2020). Pruning is an important cultivation technique that impacts the fruit quality and usefulness of disease control practices ( Glenn and Campostrini, 2011).

In the United States, the apple ( Malus × domestica) industry contributes ≈$2.75 billion to the economy ( U.S. Dept.Keywords: automated pruning branch cutting branch diameter cutting angle Malus ×domestica pruning end-effector pruning force pruning torque robotic pruning

Pruning fruit trees download