Objectives:

• To estimate the overall productivity, cost and accidental crop damage levels which can be expected when weeding shrub-dominated coniferous plantations with clearing saws;
• To compare the productivity and performance of three clearing saw cutting attachments;
• To document the effect of brushing on crop species and on non-crop species.

Experimental Design:
The experiment was installed in two portions.  The first is a completely randomized design with three replications.  The second is an unreplicated complete block design.

Treatments:

• Brushing was repeated annually in July for up to three years.
• The replicated design contains nine plots with one brushing, three brushings and an unbrushed control with each treatment replicated three times.
• The complete block contains four plots, with one, two and three brushings and a control.
• At each brushing the operators were instructed to "... cut all non-crop vegetation as low to the ground as practical ...".

Layout:
Treatments were applied to plots that were 50 m by 50 m.  Each plot contained a 20 m by 20 m macro plot in the centre.  Surrounding the macro plot were 20 crop tree assessment plots spaced 5 m apart and 10 m from the plot edge.  

History:

• 1987 - Plot establishment and first brushing.  First assessment
• 1988 - Second brushing.  Second assessment
• 1989 - Third brushing.  Third assessment
• 1990 - Fourth assessment
• 1997 - Assessment and Report
• 1999 - Presented to SISCO summer field workshop.
  

Status: Dormant

Reports and Publications:

Holmsen, S.D. and R.J. Whitehead. 1988. Comparison of clearing-saw cutting attachments for weeding young conifer plantations.  Can. For. Serv. FRDA Rep. 028. Also FERIC Special Report SR-52.

Whitehead, R.J. and R.K. King. 1990. Damage assessment after clearing-saw treatments for release of a young mixed conifer plantation from heavy shrub cover.  ECW Western Canada Sect. Res. Rep. November 26-29.

Olsen, N.H. 1991. Comparison of single and repeated brush treatments using clearing saws in a mixed shrub complex of the ICHa1. For. Can. P.F.C. File Rep. PC6171-01-1991.

Harper, G., R. Whitehead and C.F. Thompson. 1998. A comparison of manual brushing treatments in the ICHdw at Redfish Creek: 10-year results from blocks 10-13. Extension Note 20. B.C. Min. For., Victoria, B.C.

Thompson, C.F., P. Bauer and G.J. Harper. 1998. Ten-year results from a Motor-Manual Brushing Trial for Conifer Release in the ICHdw. EP 1195 Unpublished Internal Report. Research Branch, B.C. Min. For., Victoria, B.C.