Final results from a trial to test the effect of plot size on Eucalyptus hybrid clonal ranking in coastal Zululand, South Africa

Hybrid clones with Eucalyptus grandis as one parent and, generally, E. urophylla as the other parent, are deployed commercially as monoclonal blocks by Sappi in the subtropical region of coastal Zululand, South Africa. In monoclonal blocks genotypes are grown in self-competition. Performance under this scenario may not necessarily correlate well with performance where genotypes are competing for resources with a number of genetically dissimilar genotypes. There is an uncertainty whether plot configuration or size influences clonal ranking and therefore selection of clones for commercialisation. Final results at age eight years of a trial testing eight selected Eucalyptus hybrid clones in single-tree, eight-tree line, and eight x eight tree square plots are reported in this paper. Ranking of the eight clones between the half rotation (44 months) and full rotation (94 months) measurement have remained stable in the single-tree and line plots, but there have been some changes in the square plots. At 94 month...