Decay resistance of preservative injected poplar and its process of preventing white rot fungi infection

This study initially investigated decay resistance of preservative injected poplar and its infection mechanism of preventing white rot fungi. The living poplar was injected with different concentrations (0.0, 0.5, 1.0 and 1.5 wt.%) of alkaline copper quaternary (ACQ). Using the scanning electron microscopy, the process of preservative injected poplar wood preventing white rot fungi infection at different tree heights were examined. The decay resistance test results showed that the decay resistance of preservative injected poplar at different tree heights was significantly different. With the increase in tree height, the decay resistance decreased, and the higher the ACQ concentration, the better the decay resistance. The white rot fungi infested the poplar wood with the vessels as the breakthrough point, being spread to other cells through pits. The white rot fungi degraded wood cell walls by secreting enzymes and preferentially degraded the parenchyma cells.

Leachability of ACQ-D after three different preservative treatments

In this study, the ACQ-D preservative treatments of poplar wood were carried out using the method of living tree injection treatment and the leachability was examined by comparing with the traditional treatment methods, namely, immersion and pressure treatment. In addition, the effects of injection experiment on the soil environment and preservative stability in wood were examined. The results showed that the effect of injection experiment on soil environment around the treated trees was insignificant and the preservative stability of the injection treatment was the best among three methods. ACQ-D preservatives leached easily as the increase of concentration. The retention of preservative after pressure treatment was greater than that of the injection and immersion treatment, but after the leaching tests, three methods had the same preservation grade.