OK, from what I understand so far, we only really need to break the bark (actually this is obvious, come to think about it, as even a shallow cut leads to sap leakage on many trees).
The advantage of the auger is that it makes a nice neat hole (I get the feeling this only needs to be about an inch deep) that is deep enough to support a tube. The round hole also means that you can get a nice tight fit with the plug (from the same tree and cut flush with bark surface).
Alternatively, if no tube, I believe that a small peg with a notch cut into the top side can be inserted into the hole to guide the sap.
Peter_t - was I right in my assumption that it is the phloem we need to tap (positive pressure due to mass flow, contains organic material and sugars)? As opposed to Xylem (ions and water, under water tension, so negative pressure)?
The advantage of the auger is that it makes a nice neat hole (I get the feeling this only needs to be about an inch deep) that is deep enough to support a tube. The round hole also means that you can get a nice tight fit with the plug (from the same tree and cut flush with bark surface).
Alternatively, if no tube, I believe that a small peg with a notch cut into the top side can be inserted into the hole to guide the sap.
Peter_t - was I right in my assumption that it is the phloem we need to tap (positive pressure due to mass flow, contains organic material and sugars)? As opposed to Xylem (ions and water, under water tension, so negative pressure)?
the sap flow in the phloem is different depending on the time of year. in the start of spring the sap flows up to the buds to give energy to develop leaves etc. after that untill autumn sap flows down to the roots to store the sugars projuced by photosynthesis. water and minerals are drawn up the xylem to the leaves by transpiration.
