Now you have me examining my spelling of
watersprout! Take out an 'r' and you have an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water. Apparently my inherent spelling springs from
waterspout ... which in a sense reflects the energy of a
water sprout in a fruit tree. Botanically speaking, this term relates to the term "epicormic":
Quote
Dave's Garden (website)
An epicormic sprout is a shoot that arises from latent or adventitious buds. Also known as a water sprout, they form on stems and branches, and suckers produced from the base of trees. In older wood, epicormic shoots can result from severe defoliation or radical pruning.
From the Greek epi, upon and kormos, a branchless tree trunk.
Pacing growth response in renovating an overgrown tree seems pivotal to me as regards the 30 percent rule. Year two is when serious thinning cuts come into play and these will trigger far less water sprout production. Allowing the weaker suckers another growing season to "settle" is part of this, and those in turn will have a chance to grow laterals in year two and form fruit buds by year three. Such young wood can be bent into a favorable position to fill a hole in the tree structure as well.
Lost Nation OrchardZone 4b in New Hampshire