Effects of Leader Topping and Branch Pruning on Efficiency of Douglas-Fir Cone Harvesting with a Tree Shaker.

摘要

In 1983, A study was conducted to evaluate the effects of leader topping and branch pruning on the efficiency of tree shaking to remove Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) cones. Removal efficiency for three topping and pruning treatments averaged 69 percent, whereas for the uncut control treatment it was 62 percent. The treatment combination that resulted in the greatest cone removal (70.8 percent) was cutting the last 2 years of growth from the leader but not pruning lateral branches. The pruning-topping effects were not additive, possibly because branch pruning several weeks prior to cone harvest resulted in premature removal of a portion of the most easily shaken cones.