Can gravity line go uphill?

[huxta]

I will be putting up some 3/16 gravity lines this year. I have about a 40 foot drop but at the top of the line, there are a few trees I would like to get on the line. Problem is, they are on the back slope of a hill. It would have to flow uphill about 5 ft to get over the hill. Would the vacuum be able to pull the sap from those trees?

[sugarsand]

It should pull uphill some what, another thing you can do is tap those trees higher to create

slope.

sugarsand

[WESTVIRGINIAMAPLER]

Proctor did a study this year where they tapped below the lateral line with mechanical vacuum and and got slightly more sap than tapping above the lateral line if my memory serves me correctly. More study will need to be done on it but the reason they did it is that some trees have been tapped out above the lateral line by some producers so this allows them to open up an entirely new tapping band on the tree and gives many years of growth and healing above the lateral line.