Agronomic Aspects of the Cultivation of Olearia phlogopappa in Relation to Essential Oil Quality and Yield

Clonal material from the Australian endemic Olearia phlogopappa Labill. D.C. was grown under field conditions to determine the effects of spacing, canopy shape, harvest frequency and pruning on biomass production and essential oil yield. The greatest yields were achieved with no pruning, 0.8m spacing, a hedge type canopy and a biannual harvest. In addition, the Neider fan design was used to determine the effect of a range of planting densities (1.11 to 4.99 plants/m2), on the yield and quality of essential oil. The optimal yield of oil per hectare was obtained at a density of 4-5 plants/m2. This is a direct result of increasing biomass, since there was no significant difference in the oil yield/g dry matter between density treatments. The quality of essential oil, as determined by the percentages of kessane and liguloxide present, did not alter with increasing density. Morphometric parameters were also independent of density.