University of Vermont

Proctor Maple Research Center - Underhill Center - Vermont

Tapping Guidelines and Organic Defoamer

UVM PMRC Tapping guidelines and
organic defoamer project


The objective of this project is to generate more robust, empirical data to support the tapping guidelines used in maple production, and identify more effective solutions for foam control in certified organic maple operations. This work is supported by Organic Transitions Program Grant 2016-51106-25717 from the USDA National Institute of Food and Agriculture. Project updates, events, and data will be posted on this page.


August 2018

Project Annual Progress Report is available.


November 2017

taphole woundsWe’re currently seeking trees for a research study this fall on internal staining associated with taphole wounds. If you have a few trees that you’d be willing to have felled for science, or have a few blowdowns in your woods (any size tree from 4” and up will work), please contact: Abby van den Berg (802-899-9926,

September 2017

study plotsThis summer, with the help of many certified organic maple producers and organic certifiers, we completed the setup of a field experiment that will measure the impact of tapping on tree growth and health. Study plots were established at 15 sites across Vermont and NY with trees that have never been tapped before – at each plot, 50 trees in each 5 size classes were selected; 25 trees (10 in each size class) will be tapped as usual for production, and 25 will remain untapped as controls. The diameter growth and health of each tree will be measured annually. This will provide some of the first empirical data on the impact (if any) of tapping on trees – essential information to ensure tapping guidelines will result in sustainable outcomes. Thank you to all of our producer partners for helping to make this happen!

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Last modified August 27 2018 04:20 PM

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