Conifer Cone Harvesting: An Experimental Approach

ABSTRACT THE objective of this study is to quantify various para-meters affecting the vibratory removal of the conifore cones. The three conifer species used in this experiment were (a) Ponderosa Pine, (b) Douglas Fir and (c) Western White Pine. The initial test was to determine pull and torsional forces required for cone detachment. The effects of various factors such as amplitude, direc-tion, duration and repetitions of vibration on cone removal and damage to the tree were studied. In order to isolate these factors, individual limbs from each of the three species were cut and vibrated by a laboratory shaker. The resulting data indicate the constraints pro-vided by the tree and the best approach to use in attemp-ting to harvest the cones by whole tree shaking.