International supply chain handling practices and the quality of heat-treated, white oak veneer logs

Abstract

The most promising alternative to the methyl bromide fumigation of exported logs is steam-heating the log in a vacuum. Research has confirmed that steam heating to 56 °C for 30 minutes kills all viable propagules of oak wilt pathogen (Bretziella fagacearum) in the sapwood of oak logs. The purpose of this study was to determine whether this heat-treatment method has any effect on the quality or value of white oak veneer logs shipped between the US and EU. Seventeen steam- and vacuum-treated and seventeen untreated control logs were shipped from Baltimore, Maryland to the Czech Republic, for processing into veneer, between December 2021 and February 2022. The treated and untreated logs were sawn into flitches, soaked in hot water vats, sliced, dried, and the veneer from each log was graded for quality. Each log was assigned a value based on the veneer quality and yield. The average value of treated log was 1,547 €/m³, and the average value of the untreated logs was 1,539 €/m³. The null hypothesis was statistically confirmed. Therefore, it is concluded that the 56 °C/30 min, sapwood heat treatment using vacuum and saturated steam had no adverse impact on the value of the white oak veneer logs.