Physiology of fibre development in Eucalyptus globulus

Plantation Eucalypt forests are an important source of wood fibre for pulp and paper manufacture. Length is one important fibre dimension affecting paper properties and this project has investigated the within-tree variation in secondary xylem fibre length in Eucalyptus globulus Labill. Evidence is presented that cambial region gibberellins are a likely causal factor in secondary xylem fibre elongation.;A strong positive correlation (r = 0.757, df = 7, ;Gibberellins ;Localised stem injection of trinexapac-ethyl, a late stage acylcyclohexanedione type inhibitor of GA biosynthesis, was used to reduce endogenous cambial region GA levels. High doses of Primo also reduced the elongation of secondary xylem fibres and the radial number of primary walled differentiating fibres undergoing elongation. Fibre elongation was positively correlated with endogenous cambial region levels of both GA...