The efficacy of Sentry® as a treatment for the control of sapstain in pre-infected radiata pine
C Chittenden, J G van der Waals, B Kreber, R N Wakeling
Experiments were conducted to determine the efficacy of Sentry® when used to control sapstain fungi on radiata pine branch billets stored under high fungal hazard conditions. Prior to antisapstain treatment, the billets were pre-infected with a mixed inoculum of staining fungi and held from zero to 10 days at 25°C and 75% relative humidity. This was done to produce billets with different degrees of fungal pre- infection. Following each holding time, replicates were dipped in Sentry® at concentrations ranging from 3.5%-14% w/v product. After antisapstain treatment, the billets were stored for one month at 30°C and 90% relative humidity, to simulate conditions that could be met during transport and storage of logs in the tropics. Each billet was then sawn into 10 discs and the newly-cut face assessed for fungal degrade. For two-day-old billets, 7.5% Sentry® w/v product gave satisfactory control of sapstain in one trial, whereas in a second trial 10% Sentry® w/v product was required. However, satisfactory protection was not achieved with any of the concentrations of Sentry® tested for billets held longer than two days before treatment.