Influence of silvicultural treatment on growth and wood density of Eucalyptus grandis grown on a previous pasture site

Summary The effect of a number of silvicultural treatments on wood basic density was examined at butt height (10–25 cm), 25% and 50% of total tree height in 11.3 year old plantation trees of Eucalyptus grandis (Hill) Maiden grown on a previous pasture site. These treatments included: an untreated control (C); insecticide (I); weed control (W); fertilizer (F); and a combination of fertilizer, weed control and insecticide (A). Tree diameter increased progressively in treatments I, C, F, W and A. At all heights, average under-bark diameter was 15–18% greater in treatment A than treatment C. In contrast, average under-bark diameter was 6% less in treatment I than C. Wood basic density in treatment A was generally higher than in treatment A and to a lesser extent treatments W and F. Most between-treatment differences in density occurred at butt height where density increased through treatments C, W, F, A and I. Density generally increased with age, although at 50% of tree height there was an initial decrease i...