Clonal screening plot type can impact growth predictions of clones deployed monoclonally

Authors: Rajesh K. Sharma, Euan G. Mason, Charles T. Sorensson
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2008, Issue N.Z.J.For. 53(1) 2008, pp 6-11, May 2008
Publisher: New Zealand Institute of Forestry

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Abstract: Productivity of ten clones (genotypes) was contrasted in clonal mixture plots and monoclonal block plots of radiata pine (Pinus radiata D. Don) to age 12 years at a site in Canterbury, New Zealand. The objective was to determine if plot type (monoclone vs clonal mixture) biased the growth and survival of any clones, and therefore impacted breeder’s abilities to rate clones correctly for long-term growth. The experimental design was a randomised complete block with three replications. Each plot contained 40 or more trees. The trial was installed at 1250 stems/ha and left un-thinned. Plots of deviations in diameter at breast height (DBH) and stand basal area were applied to critically evaluate each clone’s growth sensitivity to plot type. Overall DBH and survivals were similar in monoclonal and clonal mixture plots, but mode of deployment altered the DBH and basal area rankings of some clones. Thus, it appears that the standard single-tree-plot designs used by breeders, which are a form of intimate clonal mixture, could allow breeders to overlook clones that could grow more rapidly at older ages in monoclonal stands.

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