The Quebec Farmers Union has implemented random testing for the doping of maple trees because a practice outlawed two decades ago is making a comeback: using paraformaldehyde on maple tree bore holes.
The compound occurs naturally in trees but in high doses, it stops the tree from closing up the holes, meaning more sap can be taken.
However, in addition to be toxic to humans, para-formaldehyde can kill trees by leaving them vulnerable to insects.
Now that the compound is available in a spray instead of the old-style, easily-detectable capsules, its use is harder to detect, so the Farmers Union is conducting random sap tests.
Fifteen producers have been nabbed for tree doping in the past three years.
One is defending himself against the accusation, saying the tests may be picking up trace amounts left in the trees or the soil by use years ago.