Effect of nitrogen, location, and harvesting stage on peppermint (Mentha x piperita L.) productivity, oil content, and composition.

摘要

Peppermint dry weight biomass was higher in Verona (8119 kg/ha) than in Stoneville (6115 kg/ha). Overall both, oil content and yield were higher in bud formation stage than flowering stage. The levels of major essential oil constitutes were (-)-menthol 26--30%, (-)-menthone 14--21%, (+)-menthofuran 5--11%, and eucalyptol 3--4% of total essential oil content at flowering stage. Menthone content and its yield were higher at first cut; however, (+)-menthofuran content and its yield were higher at the second cut at bud formation. Although N fertilizers at rate 80 kg/ha did not affect essential oil content and yield at cut 1, N rate at 80 + 80 kg/ha increased oil yield at cut 2.