Crop tree release is the selection and release of desirable trees by removing adjacent competing trees.
Lamson, Neil I.; Smith, H. Clay; Perkey, Arlyn W.; Wilkins, Brenda L. 1988. HOW to Release Crop Trees in Precommercial Hardwood Stands. NE-INF-90-88. [Radnor, PA]: U.S. Dept. of Agriculture, Forest Service, Northern Area State & Private Forestry