Why is the brix so low?

[Ed R]

There can be changes year to year in the sap sugar concentrations in an individual tree, group of trees, a whole woods, or even the state of Maine. Many are due to the weather, the amount of rainfall and sunlight and the timing of it the previous year/s. Another big factor is what went on the previous year reproductively with the tree/s, did they seed up heavily. Over all tree health or stress is another factor, were there any insect issues ?