Sentry®), a new antisapstain formulation for protecting logs and lumber. - Part 1: advances in protection of New Zealand radiata pine logs
R N Wakeling, D R Eden, C M Chittenden, J G Van der Waals, B Carpenter, I Dorset, R Kuluz, J Wakeman, T Price, B Nairn
Until recently antisapstain formulations gave approximately 10 weeks protection to radiata pine logs and even within this time frame protection was often not consistent. Industry requires 20 weeks protection. The degree of protection sought by industry is in the order of 90-95%. For example, this equates to a maximum of 5 - 10% surface cover of sapstain in the first whole veneer produced from a peeler log. Recent research conducted by Forest Research, Chemcolour Industries (NZ) Ltd and Fletcher Challenge Forest Ltd. has resulted in the development of antisapstain treatments that meet the efficacy requirements of industry. This has been achieved by overcoming the underlying difficulties of treating logs: 1. deliverling an even layer of fungicide to the inherently non-homogenous logs surface, that remains intact for the duration of the protection period sought, 2. arresting inevitable pre-infection by sapstain fungi that occurs during commercial log handling regimes, by using specially formulated mixtures of fungicides of different mobility. One of these treatments, called Sentry®, is now poised for commercial use in New Zealand for treating export logs having undergone an extensive suite of field and mill trials over a two year period. Results of mill trials of Sentry® used on full size logs are presented. The consistently high levels of protection demonstrated by Sentry® in a large number of field trials, on-shore and export commercial mill trials, represents a quantum leap of performance for radiata pine logs over protection given by previously availabie formulations.