I think many have this internal fascination and curiousity of trees because they outlive us by lots of years. Among the newest discoveries are the realization of how any drought or physical damage to the vascular system will invite disease. Tree vascular systems are physical precision operators of conducting minerals and water much like a copper wire and elecricity and electron perspective to deliver energy sense. Meaner of the unfriendlier diseases capitalize on a tree failure of the vascular system until death. Lack of water in summer months promote these. Lack of a good root base also promote the same, in the same way as interior Alaska spring breakup situations do where the top of fruit trees tend to try and draw water from roots yet frozen. 

So indeed hats off (kind of congradulations) to the amazing ways scientists are now revealing how to have farmers in cold growing climates make best investment choices. But I think this applies to us PNW folk as well on longevity of apricot trees enduring dry summer verses bacterial pseudomonas syringae, also known as common gummosis, due to the phsically damaged vessels of the vascular system as seen often in apricot.