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.