The potential utilization of catalase enzyme activity of wood microflora has been examined for the non-destructive assessment of variously treated field trial stakes. Catalase activity was detected colorimetrically by coupling it with the oxidation of a redox initiator (2,6-dichloroindophenol) or by direct visualization using an agar overlay technique. The colorimetric assay was found to be applicable to assessment of untreated stakes, but was insensitive to small variations in activities within treated stakes. The agar overlay technique, however, showed good correlation with respiratory activity within variously treated stakes and may provide a useful adjunct to the subjective assessment of either field stakes or wood blocks in soil beds.