UF Tree Production Website

I had a grower asking some questions about proper pruning techniques and the proper removal of lower branches along the trunk in field production oaks.  Specifically, how much, when, and how long  are the branches pruned.  We found the answers and a whole lot more information than could be digested at one sitting by going to UF's Environmental Horticulture website.  Here Dr. Ed Gilman has an extensive nursery production tree website.  He has got extensive information on how to prune during the production stages of nursery trees to arrive a quality product.  For further reading here is the link to the website.  http://hort.ifas.ufl.edu/woody/nursery_production.shtml 
By the way, the answer is to leave as much as possible of the lower branches as long as the diameter is not sufficient to compete with the trunk.  For live oaks, pruning the lower branches to a cone around the trunk is acceptable.  The longer the branches  the larger and stronger the trunk will grow.  Pruning to about 20" diameter cone around the trunk would work.  Then as the canopy develops and becomes about 90% of the entire tree canopy, you can prune the  lower branches to the main trunk.