Effects of tree guards and mulching on plantation establishment of 'Tasmanian Native Pepper' (Tasmannia lanceolata (Poir.) A.C. Smith)

The leaves of Tasmannia lanceolata contain the polygodial compound, that is used commercially for its flavoring and antimicrobial properties. Currently leaves are harvested from native stands. Plantation production would enable the use of superior clones in terms of polygodial yield and quality; however establishment has proved problematic. Two trial plantations were established in Southern Tasmania that included treatments of tree guards and plastic and wood chip mulches. The objective was to evaluate the effect of mulch type and tree guards on plant growth to benefit the further expansion of the T. lanceolata plantation estate. Tree guards increased plant height at both sites but decreased stem diameter at one site, and plastic and organic mulching increased plant height at one site. Photosynthetic rates of plants were increased by tree guards under both low and high light conditions. Yield of the most important plant extract component, polygodial, was unaffected by tree guards, while organic mulching decreased polygodial as a percentage of volatiles at one site.