Variation in survival, growth and stem straightness in <i>Eucalyptus urophylla</i> provenances in the Southern Highlands region of Tanzania

Abstract

Lack of quality planting materials has significantly limited productivity and quality of commercial forestry plantations in Tanzania. A  provenance/progeny trial of Eucalyptus urophylla was established to test performance in order to select the best planting materials for  future plantation activities. A complete randomised block design was used whereby 30 families from 8 provenances within 6 replications  were tested. At 13 years tree survival, growth (diameter at breast height and height) and stem straightness were assessed. The results  indicate that there were highly significant differences (p < 0.05) among provenances and families in survival, height, breast height  diameter (DBH) and stem straightness. The overall survival ranged from 79.0% to 96.2%; height ranged between 24.9 and 32.5 m; and  DBH ranged from 18.7 to 24.5 cm. Overall, results from this study show that provenances Alassannaru, Elun kirpas, Nesunhuhun and Nakana ulam have better growth performance and stem form than others. These results provide valuable information on the growth  performance of different provenances and families of E. urophylla. The provenances and families selected with best performance can be  used in developing improved seeds for plantation establishment and/or selection of plus trees for vegetative propagation as candidate  clones for a clonal testing programme in Tanzania.