Recent advances in protection of unseasoned radiata pine wood in New Zealand

Radiata pine logs exported from New Zealand are susceptible to mould, sapstain and decay. Protection of logs from fungal degrade has not been achieved using conventional antisapstain treatments. A novel antisapstain treatment called Sentry® meets the efficacy requirements of industry by overcoming some underlying difficulties of treating logs by delivering a deep envelope of treated wood that remains intact for the duration of the protection period sought, and by arresting inevitable fungal infection that occurs during commercial log handling regimes. Sentry is a solubilised concentrate containing methylenebisthiocyanate (MBT) and 2-n-octyl-4-isothiazolin-3-one (OIA). Log mill trials compared the performance of Sentry with a commercial standard on logs of ages 1–14 days from felling. For log ages of 0, 2, 4, and 7 days, mean percentage sapstain for Sentry (equivalent to 0.5% w/v MBT plus 0.125% w/v OIA) was 0, 9, 21, and 32, respectively, compared to 3, 31, 54, and 54 for the commercial standard. The ability of Sentry to protect older logs is of considerable value to forestry operations because rapid extraction is often not feasible or increases costs. For block-stacked radiata pine boards stored for 12 weeks, Sentry, at the lowest concentration tested (equivalent to 0.125% MBT plus 0.025% OIA), gave equivalent protection to the highest concentrations of all the commercial standards.