Effectiveness of Copper chrome arsenate and used engine oil in protecting fencing posts of Ugandan grown eucalypt clone GC550 and Phoenix reclinata against termite attack

Abstract

Eucalypts and Phoenix reclinata posts are the most commonly used species for fencing posts in urban areas of Uganda. Although eucalypts are known to be susceptible to termites, fencing posts are still used untreated. In this study, the effectiveness of Copper Chrome Arsenate and used engine oil in protecting Ugandan grown Eucalyptus grandis × Eucalyptus camaldulensis clone and Phoenix reclinata fencing posts against termite attack were assessed. The objectives were to determine (i) the incidence and (ii) severity of termite attack on Eucalyptus grandis × Eucalyptus camaldulensis and Phoenix reclinata fencing posts treated with Copper Chrome Arsenate or used engine oil. Ninety 2ft long samples of Eucalyptus grandis × Eucalyptus camaldulensis and P. reclinata posts were treated with Copper Chrome Arsenate or used engine and others left to act as control then buried in 1ft deep pits in the ground at a spacing of 1m by 1 in Eastern Uganda. The samples were visually inspected monthly for termite damage for 9 months. More than 80% of untreated samples of both species had been attacked by termites within the first month. Copper Chrome Arsenate treated Eucalyptus grandis × Eucalyptus camaldulensis and Phoenix reclinata samples were first attacked in the 8^th and 5^th months respectively. While used engine oil treated Eucalyptus grandis × Eucalyptus camaldulensis and Phoenix reclinata samples were first attacked in the 7^thand 5^th months respectively. The modal severity for samples of both species treated with either Copper Chrome Arsenate or used engine oil was class 1 (less than 1% of the sample volume eaten) while for the untreated samples it was class 5 (above 60% volume eaten) for the 9 months of field exposure. It was concluded that untreated posts of Eucalyptus grandis × Eucalyptus camaldulensis and Phoenix reclinata were highly susceptible to termite attack and that the protection offered by used engine oil or Copper Chrome Arsenate managed to restrict damage by termites to only less than 1% of the sample volume , over the 9 months of exposure for most of the sample posts. It is recommended that the experiment be repeated for a much longer period in order to ascertain the exact service life of the posts under these circumstances. Penetration and retentions of the preservatives in the posts should also be studied in order to ascertain their effect on the efficacy.