Studies On The Application Of Heat-treatment Of Wood Materials As A Phytosanitary Measure In Entry-exit Quarantine And Supervision

The contemporary international standard of heat-treatment for woodpackaging material (WPM) is 56℃and 30 minutes duration at the woodcenter, but this standard is not credible according to the fact that CIQ hasfound pine wood nematodes and larvae of beetles many times from theentry WPM having been treated. Previous domestic researches about heattreatment also show that the treatments with this standard cannot kill allpests in the wood due to the variable capabilities of all kinds of dryingvaults. Therefore it is important to proceed novel researches on WPMheat-treatment and set up new mode for entry-exit phytosanitary measuresand quarantine supervisions.The experiments on WPM with pine wood nematodes and longhornbeetle larvae resulted in effective combinations of "60℃at wood center,80% relative moisture and one hour disposal time" or "60℃at woodcenter, 60% relative moisture and three hours disposal time". Furthermore,in terms of the European requirement of "containing water below 20%",10 times of tests were investigated on the containing water of WPMheat-treated by drying vaults. The results demonstrated that generally theaverage containing water of WPM before treatment is 35%. To meet thequarantine qualification of below 20%, the average drying time should be30 hours integrated with the industry procedure. To verify the efficiency of entry WPM certification of heat-treatment,we conducted a survey from 2000 to 2003 at Nanjing Port on 5589batches of WPM and found 182 batches out of total 5589 batches ofWPM having living pests, a high rate of 3.3%.In order to reduce the risk of entry pest, we work out a set ofmeasures in the post-port inspections in Nanjing city. That is to check atthe harbor originally by normal procedure and take samples at the spotsor destinations of cargos, and make dynamic archives for all thequarantines actions. Meanwhile, considering the effect of the existingheat-treatment equipments in Nanjing region we set up a mode for theexit WPM of "to treat together and cancel after verification at times ofexporting", which approved to be practical for the current situations insupervised area and powerful to diminish the pest risk of entry and exitWPM.