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Home → Publications → Tree Planters' Notes → Tree Planters' Notes Volume 49, Number 3 (2000) → Removing Douglas-Fir Cones with a Lower-Crown Branch Shaker

Removing Douglas-Fir Cones with a Lower-Crown Branch Shaker

A new type of branch shaker was developed to remove conesup to 25 ft (7.6 m) above the ground. In 1997 and 1998, thelower-crown branch shaker removed 64.5% and 76.0% of thecones from trees that averaged 28 ft (8.5 m) and 40 ft (12.2m), respectively. The shaker had a crank arm mechanism thatmoved a vertically oriented 15-ft-long, 4-in-diameter (4.6-m-long, 10-cm-diameter) energy bar in a rapid oscillatingmotion. The shaker was most effective in removing coneswhen the energy bar was inserted 3 to 5 ft (0.9 to 1.5 m) intothe interior of the crown and was powered so that it completed1.5 to 2.0 oscillations per second. Shaking a 15-ft-high (4.6-m-high) zone around each tree required an average of 5.3 min,whereas shaking from 0 to 25 ft (0 to 7.6 in) required an aver-age of 11.1 min. Tree Planters Notes 49(3): 51-55; 2000.


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Author(s): Donald L. Copes, William K. Randall, D. O'Rourke

Publication: Tree Planters' Notes - Volume 49, Number 3 (2000)

Section: Geographical Perspectives

Volume: 49

Number: 3