| Abstract: | Peppermint (Mentha piperita L.) was harvested on two occasions during the growing season. Double harvesting yielded approximately 140 kg oil ha?-1. The first harvest was timed to coincide with a period of maximum oil yield per unit area (ca. 70 kg ha?1) and yielded an oil containing 39% menthol. The oil yield in the subsequent regrowth increased to approximately 70 kg ha?1, and when harvested at this stage the oil contained high levels of methol (53%). The oils produced from the double harvest programme could either be combined to resemble the Tasmanian single harvest oil or marketed as distinctive oil types. Organoleptic evaluation indicated that oil from crops 1 and 2 resembled Midwest and Yakima Valley, USA, oils, respectively. Double harvesting had no apparent adverse effect on the regrowth in the following season. |
