Variation in Growth Traits and Survival of Acacia Mearnsii Provenances in Bako, Western Oromia Regional State, Ethiopia

Abstract

An experimental study was carried out at Bako Agricultural research Center, Western, Oromia Regional state, Ethiopia. The purpose of the study was to evaluate the variation existing in different twelves (12) provenances of Acacia mearnsii and then to select the best seed sources/ provenance that suits with Bako site conditions. The twelve provenances of Acacia mearnsii namely George Town, Tasmania, N of Bemboka, New South Wales, Bawley PT, New South Wales, Tantanoola, South Australia, East Lorne, Victoria, Wonboyn Lake, New South Wales, You Yangs, Victoria, N Bungendore, New South Wales, Mt. Gladstone, New South Wales, (R)B'hill Res Kyneton, Victoria, Bodalla, New South Wales and Gloucester, New South Wales obtained from Australian used in the study. The saplings were monitored for survival rates and growth performances by measuring root collar diameters and heights. There was non-significant difference in survival among the species investigated (P>0.05). Survival percent were varies from 87.96 to 100, across the species provenance, but at the end of the experimental study (62 months after planting) the survival varied significantly (p<0.001). Non-Significant differences in height growth (P>0.05) and diameter growth were also observed. Among tree provenance greatest height (8.13 m) was recorded for the Wonboyn Lake, New South Wales (17934) followed by the N of Bemboka, New South Wales (16635) and root collar diameter (RCD) (3.01 cm) were recorded (R)B'hill Res Kyneton, Victoria (18979) followed by the Gloucester, New South Wales (18626). Lowest height (6.90 m) was recorded for (R)B'hill Res Kyneton, Victoria (18979) and root collar diameter ( RCD) (2.25 cm) was recorded for Wonboyn Lake, New South Wales (17934) provenance. Statistical analysis showed that there were non-significant (p>0.05) differences in mean diameter at different age of after planting of between provenances. The provenance of Tantanoola, South Australia (17927) performed highly in diameter at breast height (DBH) (8.09 cm) followed by Nof Bemboka, New South Wales (16635) and N Bungendore, New South Wales (18975). We recommend for the due to its superior growth and survival with the following provenance Tantanoola, South Australia (17927), N of Bemboka, New South Wales (16635) and N Bungendore, New South Wales (18975) are recommended for Bako area and other localities with similar agro-ecology.

Keywords: provenances; Acacia mearnsii; Survival percent; growth performances; root collar diameter; diameter at breast height