Lignotuber Development and Growth Parameters in Eucalyptus camaldulensis (Dehnh.): Effects of Phosphorus and Nitrogen Levels

Abstract

Previous reports of nutritional and genetical effects on lignotuber development in eucalypts are summarized. Seedlings of two provenances of E. camaldulensis, one normally lignotuberous the other non-lignotuberous, were raised under combinations of nitrogen and phosphorus levels. When an effect of nitrogen on overall growth is taken into account, there is no additional effect of phosphorus on lignotuber size or plant height, but there is an effect on the number of branches. Lignotubers were not formed on plants of the southern provenance irrespective of the plane of nutrition. In the northern provenance the percentage of lignotuber-bearing seedlings was highest at high levels of phosphorus associated with low to intermediate levels of nitrogen. At high nitrogen levels there was no statistical effect of change in phosphorus level on percentage of lignotuber formation. Nitrogen supply appears to be the main controlling nutritional factor.