Southern pine, Douglas fir, sugar maple, and red oak crossbrace units were given one or two brush treatments with sodium borate (A), copper-8-quinolinolate (B), ammonium bifluoride (C), ammoniacae copper borate (D), 4 quaternary ammonium compounds (E) or sodium pentachlorophenate (F). After five years, of the untreated controls only maple and pine units at the Gulfport, Mississippi, site and maple units at the Madison, Wisconsin, site were sufficiently decayed to evaluate the treatments. Only fungicides C and D protected maple from decay in Mississippi, but all except A and B were effective on pine. In Wisconsin, fungicides B, C, D and F protected maple from decay. -- AATA