The objective of this work was to study the constraints on biological control of bluestain in logs and investigate ways to improve biocontrol agents’ performance and consistency. We conducted a literature search and a review of recently published literature on biocontrol in forest products and other fields and developed a research plan to study some of the key opportunities for improvement. The major focus was on Cartapip® (Sylvanex), which has been successfully used earlier in Forintek’s field trials. Other systems have also been discussed.
In general, inconsistencies occur due to the biological nature of these agents and their vulnerability to different variables found in their environment (i.e. climatic factors, changes within substrates and activities of competitive organisms). To be successful, the chosen biocontrol agents have to be highly effective against a number of target organisms, persistent, able to compete with the natural flora, and able to quickly colonize and proliferate on existing and new substrates. They also have to stay attached to the substrate and be able to tolerate and maintain effectiveness for at least several months. Commercial biocontrol agents need to be produced inexpensively on a large-scale and have user-friendly formulations in order to compete with chemical-based pesticides. Efficacy of the delivery system and the environmental impact are also important to consider.
Biological control agents are perceived to be promising and sometimes the sole alternatives to chemicals. However, they continue to be under similar scrutiny to chemicals. They are strictly regulated and cannot be released into the environment until they have passed a pest risk assessment and all the data on their toxicology and efficacy are provided. Sylvanex represents a good model to study as it is among a few products that have been temporarily registered in Canada to control bluestain (PMRA-REG2004-05). In March 2006 the product changed ownership and was successfully re-registered with PMRA (Reg. No. 27561) when a temporary registration was granted until December 31, 2006.
A research plan to understand the constraints and to optimize the use of biocontrol agents was developed after studying literature and through brainstorming sessions, which included researchers from Forintek, The University of British Columbia (UBC) and Forest Engineering Research Institute of Canada (FERIC). It suggested a series of laboratory and field activities:
Experimental evaluation of different possible constraining factors of existing albino biocontrol agents to control bluestain in the lab and field
Investigation of large-scale application systems during harvesting and log storage
Study other ways of control using biocontrol agents: e.g. modified decay fungi, bacteria, insect-vector control
Study if there is any effect of biocontrol agents on insect vectors and other pests whose infestation patterns may be affected
As a part of this project, an early development of a harvester applicator system was also initiated. Some UBC mechanical engineering students developed a conceptual design of a field spray applicator system using facilities at Forintek and input from an expert panel. Tests determined that the mockup system, which tested selection and placement of different nozzle types and pressures, had the capability to evenly coat entire log surfaces. Future work should be coordinated through an industrial advisory committee and involve an equipment manufacturer and an industry champion/collaborator.