Technical note: The suitability of young fast-grown radiata pine clones for conversion into vineyard trellis posts

Abstract

In this note, we test the hypothesis that vineyard trellis posts of the required size and strength properties can be produced from young radiata pine trees obtained from clonal plantations established using a dense stocking of physiologically aged cuttings selected for fast growth, good straightness, aboveaverage juvenile wood density, and fine multinodal branching. Radiata pine trees from four different clones were all large enough to be converted into vineyard posts when they were 6 yr old. Posts made from the fastest growing clone had below-average wood density and a high grain angle and were significantly weaker than commercial posts made from 14-yr-old thinnings. Another clone, however, produced posts whose average breaking load and modulus of rupture were only 8.6 and 9.2% lower, respectively, than those of commercial posts. Posts from this clone had a low grain angle and above-average wood density as well as fine multinodal branching. We conclude that the use of selected radiata pine clones for the manufacture of vineyard posts shows promise as an alternative to the production of posts from thinnings and suggest how the strength properties of posts from clonal radiata pine trees might be further improved.