Commodity risk assessment of maple veneer sheets from Canada

Area of Science:

• Plant Health
• Risk Assessment
• Phytosanitary Measures

Background:

• The European Commission required a risk assessment for maple veneer sheets from Canada.
• Focus on freedom from Union quarantine pests, specifically Davidsoniella virescens and Phytophthora ramorum (non-EU isolates).
• Assessment considers veneer sheets up to 0.7 mm and 6 mm thickness.

Purpose of the Study:

• To evaluate the likelihood of pest freedom in Canadian maple veneer sheets.
• To assess the effectiveness of a specified manufacturing process against key quarantine pests.
• To determine pest freedom for different veneer thicknesses.

Main Methods:

• Risk assessment utilizing a systems approach for veneer production.
• Evaluation of individual process phases: log heat treatment, veneer cutting, and high heat drying.
• Expert Knowledge Elicitation (EKE) to quantify pest freedom probabilities.

Main Results:

• The systems approach is considered highly effective against insects and Xylella fastidiosa.
• Phytophthora ramorum is unlikely to survive high heat drying of thin veneers; survival possible in thicker veneers.
• Expert Knowledge Elicitation indicates high pest freedom rates (e.g., >99.8% for P. ramorum in 6mm sheets, >99.8% for D. virescens in 0.7mm sheets).

Conclusions:

• The manufacturing process ensures a very high degree of pest freedom for maple veneer sheets.
• Thicker veneer sheets (6 mm) exhibit slightly lower pest freedom compared to thinner sheets (0.7 mm).
• Wood decay fungi represent the greatest likelihood of pest presence, though still at very low levels.