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A modern maple operation relies on a tubing system with vacuum to maximize sap production. The innovation of plastic tubing originally came as a labor-saving device and not to increase sap yield from individual trees. As the materials used to produce maple tubing became more robust and vacuum pumps were employed, the increases in sap yield became obvious. There are many questions about how the use of vacuum tubing does or does not impact the tree or the sap harvested from the tree. Research done at the University of Vermont Proctor Maple Research Center sought to answer some of the common questions. To answer the question if the internal wounding associated with tapping is larger when more vacuum is applied to the tap hole, groups of trees were tapped and exposed to various levels of vacuum ranging from 15" to 25" Hg (inches of mercury, a unit also used in weather reporting, is a measurement of vacuum). A control treatment with no applied vacuum was also included. After the season was completed the trees were felled and the size of the tapping wound was quantified. The results indicate that the size of the wound was no different in trees tapped with or without vacuum. As with many experiments, the results lead to more questions and the need for additional research.