Spray Safe DSS Application Trial - 160-401

Description: Efficient and effective regeneration are critical to the sustainable use of high value fibre from Canadian forests.  Competition for light, moisture, nutrients, and space often results in growth loss during the early phases of regeneration, and as such, control of competing vegetation is required to ensure stand establishment. A number of vegetation management techniques are available and used on a regular basis by foresters in accordance with site-specific prescriptions. Among the many techniques, aerial herbicide applications are perhaps the most effective and efficient – especially in the boreal forest. Glyphosate dominates herbicide use in Canada with application to 94% of the treated areas. There have long been concerns about herbicide use from public land owners, forest certification agencies, environmental groups, and industry accountants. Cost-effectiveness and general environmental acceptability of herbicide use in Canadian forest management as well as continuous improvement in best management practices and associated technologies are required to address these concerns.  Recently, significant developments in various new technologies including differential global positioning systems (DGPS), geographic information systems (GIS), electronic guidance systems, automated booms, and remote sensing have occurred, all of which have the potential to improve the accuracy of aerial herbicide applications. While all of these technologies are used to some degree, full integration in both concept and practice has generally been lacking.  As part of an internationally collaborative effort to address this need, this project was undertaken to develop and validate SprayAdvisor as a decision support system capable of integrating scientific and experiential knowledge together with multiple new technologies; the goal being to optimize efficacy, cost-effectiveness, and  environmental protection associated with aerial application of herbicides in Canadian forestry.  Specific objectives for this multi-year project included:

  • assessment of  benefits provided by electronic guidance for enhanced uniformity of spray applications,
  • assessment of  the accuracy and potential use of automatic control of spray booms,
  • quantitative determination of  the uniformity of herbicide deposition on target,
  • quantitative determination of off-target deposition and trends in deposition through spray and riparian cut-reserve buffers,
  • comparative assessment of true-colour digital and near-infrared satellite image analysis as methods for defining phytotoxicity contours and quantification of post-spray efficacy,
  • assessment of the potential to realize silvicultural and environmental exclusion zones within operational spray blocks.


Upon full development, validation and beta-level testing of the SprayAdvisor DSS system will provide operations foresters, aerial applicators and regulators alike with an extensive suite of modeling and spatially-explicit prediction capabilities including the following:

  • on-target herbicide deposition and efficacy,
  • off-target deposition and its potential effects on representative non-target plants and animals
  • operational cost analyses under a wide variety of “what if” scenarios as part of operational planning, post-treatment retrospective assessment and analysis, and
  • a learning tool to significantly enhance understanding of the multivariate complexities of aerial spray operations and outcomes.


As such the SprayAdvisor DSS is a tool which allows full integration of all modern technologies directly into operational practice and provides users familiar with ARC-based GIS applications a capability to assess key aspects of their spray programs a priori as well as providing a mechanism for integrated acquisition and archiving of resultant data.  SprayAdvisor DSS is now poised to contribute significantly to enhanced planning and control of aerial herbicide applications as required for cost-effective, efficacious and environmentally acceptable control of competing vegetation and enhanced forest regeneration.  It is also being extended to provide similar outcomes relative to aerial applications of insecticides as required to protect mature stands from the ravages of defoliating insect pests.  Ultimately, the SprayAdvisor DSS is expected to become the critical element in best management practices for sustainable forest management and environmental protection in Canada.


The Project Team:  Dean Thompson, CFS, Harold Thistle, USFS, Brian Richardson, SCION



Draft: Thompson, D. et al. 2007. Integrating Technologies to Optimize Aerial Herbicide Applications in Canadian Forest Vegetation Management. Draft Manuscript


Tree Tips:

TreeTip for Project 160-401



Development and Validation of Spray Advisor DSS for Aerial Herbicide Application in Canada, December 2006

Development and Validation of Spray Advisor DSS for Aerial Herbicide Application in Canada, March 2008

SprayAdvisor DSS- Boreal Seminar Kapuskasing, June 2008

Status Reports:

 Status Report (2007-2008)

Project Work Report (2007 - 2008) 


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