- [Mark] This is Mark Isselhardt,
maple specialist with University of Vermont Extension,
and this is another "Vermont Maple Minute."
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 at the University of Vermont
Proctor Maple Research Center sought
to answer some of those 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 inches to 25 inches of mercury.
Inches of mercury is a unit also used in weather reporting,
and it is a measurement of intensity 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
This is Mark Isselhardt,
maple specialist with University of Vermont Extension,
and this is another "Vermont Maple Minute."