Mechanical Pruning (IMAGE) University of California - Davis Caption Using mechanical pruning like above can save between 60% to 80% of labor operation costs per acre compared to manual pruning alone. Credit Hector Amezcua/UC Davis Usage Restrictions Please credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.