Scion - Root stock interaction
Well it's that time of the year. I know it's difficult to make scientific experiments on that matter, so I ask the experienced on the matter.
Can I influence the properties of the scion by selecting different root-stocks??? and vice versa, can I change the properties of the roots with different scions?
I'm thinking in terms of drought tolerance (but I wouldn't mind opinions on vigor as well)
For example, if I want to graft a Picea sitchensis cultivar. Can I make it more drought tolerant if I choose Picea pungens root-stock instead of Picea abies? The same grafted on Picea sitchensis will have completely different drought tolerance than the one grafted onto pungens? What about their annual growth then? what about full sun tolerance? I guess Picea pungens roots will drive less sap upwards...?
Please, ones with experience, do share your thoughts whenever you find the time...