Protection measures of Juniperus procera Hochst. ex Endl. (Cupressaceae) and Eucalyptus deglupta Blume (Myrtaceae) sawn timbers against subterranean termites and fungal attack at Miesso, eastern Ethiopia

Abstract

Bio-deterioration of forest products in the construction and furniture sectors is considered an economically important problem in Ethiopia. A study was carried out on treatability (laboratory test) of Juniperus procera and Eucalyptus deglupta sawn timber stakes with preservatives against subterranean termites and fungi at Miesso locality. There was significant difference (P<0.01) in Copper Chromium Arsenate (CCA) uptake and retention between the two timbers. The absorption and retention of E. deglupta pressure treated with CCA was 200.77 kg/m3 and 6.02 kg/m3, respectively while that of J. procera stakes was 2.06 kg/m3 and 0.06 kg/m3. Significant differences (P<0.01, multi-factor ANOVA) were observed between CCA treatments and the untreated control; among preservative application techniques; between the timber species and length of field exposure periods and in the interactions between timber species and preservatives. Sapwoods were more deteriorated than heartwoods for both species. All the control stakes of E. deglupta deteriorated and were felled by termites during the first year and J. procera was deteriorated by termites to 27.5% but were not attacked fungi up to third year. Termites and fungi attacked majority (80%) of E. deglupta stakes pressure treated with CCA to 37.5% and 7.5%, respectively, during the third year, while J. procera stakes were degraded to 5% by termites but intact by fungi. Termites showed more degradation than fungi. Treatments with used motor oil were less effective than CCA but much better than the control. The timbers are recommended for different construction and furniture uses after adequate preservation measures and large scale plantations establishment. 

Keywords: Bio-deteriorating agents, Copper chromium arsenate (CCA), Eucalyptus deglupta, Juniperus procera..