Determining Nursery Life Span Of Populus In Ethiopia Authors: Diriba Nigusie Debele* and `Tesfaye Humnessa Bedane Introduction The effort to mitigate current changing climate and meet the demand for fuel and construction wood could be achieved with an introduction, evaluation and management of economical tree species in Ethiopia. Production of planting material and testing methods of establishment of fast growing species such as populous is a means to put baseline information for ilarge scale promotion to achieve the escalating demand of different wood products. Thus, this activity is designed to address nursery lifespan of populus tree seedling. Nursery life span of tree seedling varies based species type and location. Accordingly, determining nursery lifespan of tree is important to produce mass of seedling in planning of afforestation and reforestation and of industrial plantation. Objective To determine the impact of cutting thickness on growth performance on populous tree seedling in nursery station of Central Ethiopia environment and Forest research center. Materials and methods Description of the study site The specimen was collected from three locations: Qalamino, Mekele and Addis Ababa, and then propagated at nursery station of the Central Ethiopia Environment and Forest Research Center. The rate of propagation was assessed at nursery level by sub-sampling the cuttings into base, middle and tip and data on seedling height and root collar diameter was collected for one year. In addition, rootability was assessed at green house in three soil substrate (nursery soil composite, gravel rock, and mixture) and data was collected for successive two months (Figure 1). Figure 1: Populus propagation Experimental design Completely randomized design (CRD) was employed for this study. Data collection and analysis Data on root collar diameter (RCD in cm), number of leaves and height (cm) of shoots was collected every week for 60 successive days. Data analysis was made using SPSS 20 software. The mean difference in RCD (cm), height and number of leaves of the seedlings was estimated` using one-way ANOVA. Pearson correlation was carried out for specific variables. Results The results of the study reveal that though there is no significant variation in root collar diameter of branch parts, in all the three durations (30, 45 and 60 days), the RCD of the middle part of cutting out weighed that of base and tip (figure 1). Figure 1: Root collar diameter (cm) of populus shoots per cutting On the contrary, except 30 days after planting, height (cm) growth of shoots of base part of populus cuttings is greater than the middle and the tip (figure 2). Figure 2: Height (cm) of populus shoots The study reveals that the leaf number of the shoots of the cuttings was more at 45 days after planting (Figure 3). This may be due to the shedding of the leaves as it gets matured (60 days after planting). Also it is possible to produce populus seedling either from a bottom, middle or tip of a one year old branch. The result also shows that there is no significant difference among periods and parts of branch cuttings (base, middle and tip). Conclusion and Recommendation This study implies that populus can reach plantable size within short period of time (one or two months) that requires little resource in plantation forestry. This may encourage investors and small scale farmers to engage in production of seedlings and establish populus plantations that could be a raw material for pulp, paper and match industries. . References Bayley A.D. and Kietzka J.W. 1997. Stock quality and field performance of Pinus patula seedlings produced under two nursery growing regimes during seven different nursery production periods.New Forest 13: 341–356. Jacobs D.F., Salifu K.F. and Seifert J.R. 2005. Relative contribution of initial root and shoot morphology in predicting field performance of hardwood seedlings. New Forests.