Water shoots grow through out the season and in the winter they are prunned back to the beginning node. They are unwanted because they tend to have a reaction to the manipulation of pruning that keeps the tree from continuing to grow up. The apple trees at this orchard and most commercal orchards allow only one central leader. The tree wants more then one. Therefore all water shoots are prunned back which also decreases vigor and inhibits fruiting.
This orchard I am working on has some variety for commercial eating apples, I will be gathering different varieties of water shoots (pencil width) to graft into trees at my community garden. Grafting is a way to save genetics and save money! I will be posting more on grafting soon.
Water shoot can be used to make small baskets, kindling, and the best thing to do is to grab some meat or fish from a local farmer, and use the fresh shoots and other branches that have been prunned off for a BBQ. The wetness from the wood makes a smokiness that contribute to the meats flavor. Apple smoked venison, lamb, cod etc. I've been making chop sticks with the shoots as well, they are a great gift and are put to use. Mostly it keeps me sane as I wait for the season of spring to come into light.