A study of the efficacy of antisapstain formulations containing triazole fungicides
IRG/WP 93-30021
R N Wakeling, N P N Maynard, R D Narayan
This document gives efficacy data for antisapstain formulations based on triazole fungicides. A rapid (3 week) laboratory screening method was used to determine the efficacy of six triazole fugicides alone and in combination with other fungicides. Field trials were carried out of three promising formulation types, each comprising a triazole compound as the primary fungicide in combination with a secondary fungicide system. Of three triazoles tested in field trials hexaconazole gave significantly (5% probability level) better protection than flusilazole and cyproconazole for all three formulation types. The relatie performance of flusilazole and cyproconazole depended on the type of formulation. Type 3 formulations of hexaconazole (0.03% w/w) and flusilazole (0.05% w/w) and a Type 2 formulation of hexaconazole (0.05% w/w) gave exceptional protection to block-stacked radiata pine for thirty weeks with between 76 and 84% of boards having 5% or less of surface fungal degrade. The best commercial standards in field trials were Copper-8 hydroxyquinolinolate (Cu-8) (0.24% w/w) (Cutrol 375) and Cu-8 (0.15% w/w) plus carbendazim (0.15% w/w) (Hylite Extra) which at thirty weeks after treatment had a majority (> 80%) of boards with between 25 and 75% surface fungal degrade. These concentrations of Cu-8 and Cu-8 plus carbendazim are between 2 and 3 times what are normally used in New Zealand. At thirty weeks sodium pentachlorophenate (0.5% w/w) plus borax (1.5% w/w) had 40% of boards with between 26 and 50% degrade, 40% of boards with between 51 and 75% degrade and 20% of boards with between 76-100% degrade.