CODIT stands for Compartmentalization of Decay in Trees, and sugar maples are darn good at CODIT! Mark Isselhardt, during the 2021 virtual Ohio Society of American Foresters spring meeting, gave an excellent microscopic and physiological explanation of how maple trees wall off and seal up old tapholes.
Why does understanding compartmentalization matter to a maple producer? Compartmentalization creates the all-important non-conductive wood that sugarmakers try to avoid with each year’s new taphole. And just in case you were wondering – how much does it matter? Through work conducted at University of Vermont’s Proctor Maple Research Center, Mark Isselhardt document sap yield declines of 70-75% when a taphole intersects non-conductive wood.
Watch this time lapse video of maple research taking place at the Ohio State Sugarbush located on the OSU Mansfield Campus.
Across 13 racks with 5, 6, or 7 canisters each, the OSU maple team emptied sap to monitor individual tree yield and sap sugar content…daily! The 75 research canisters will help us answer questions about how red x silver hybrid trees (Acer freemanii or “rilver” for short) compare to sugar maple production standards. The PVC canisters are a new design engineered by the team, and vacuum consistently achieved levels in the 22-25 pounds range. A drill pump mounted on a standard cordless drill boosted our sampling efficiency, and a digital Misco refractometer handled sugar readings.
While the data won’t be formally analyzed for a bit, we were surprised just how variable individual trees performed based on sap volume as well as sap sweetness. A couple trees achieved sugar content readings over 3 even at the end of the season. While other trees struggled to break 1.2 or 1.3% all season. For yield, 2-3 gallons a day was average for some trees. Normal for others amounted to just 1 or 2 quarts. The team is pulling down the research equipment now for off-season storage.