|Zheljazkov, Valtcho - Mississippi State Extension Service|
|Cerven, Vasile - Mississippi State Extension Service|
|Ebelhar, Wayne - Mississippi State Extension Service|
|Horgan, Thomas - Mississippi State Extension Service|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2009
Publication Date: 8/16/2009
Citation: Zheljazkov, V.D., Cerven, V., Cantrell, C.L., Ebelhar, W.M., Horgan, T. 2009. Effect of Nitrogen, Location and Harvesting Stage on Peppermint Productivity, Oil Content and Oil Composition. HortScience. 44(5):1267-1270.
Interpretive Summary: Peppermint (Mentha piperita) is an aromatic plant grown for production of essential oil, a major aromatic agent, or dry leaves, which are used in herbal teas. Peppermint essential oil is used in a number of consumer products such as chewing gum, toothpaste, mouth washes, in pharmaceuticals, confectionary and aromatherapy. Peppermint is currently not a common crop in the southeastern USA. Recently, there has been an interest towards peppermint as an essential oil crop for this region. A field experiment was conducted in 2007 in Mississippi, to determine the effect of N (0 and 80 kg'ha-1), location (Verona and Stoneville), and harvesting stage (bud formation and flowering) on peppermint productivity, oil content, and composition. From this preliminary work at two locations it has been demonstrated that location and harvesting stage had significant effects on peppermint oil yields. Peppermint essential oil yields were maximized at bud formation. Location and harvesting stage had significant effects on the concentrations and the yields of the major peppermint oil constituents. The range of the quantified concentrations of peppermint oil constituents under Mississippi climate were: (-)-menthol at 26 – 30 %, (-)-menthone at 14 – 21 %, (+)-menthofuran at 5 – 11 %, and eucalyptol at 3 – 4 % of total essential oil. Overall, peppermint biomass yields, oil content and oil yields, and the concentrations of the major oil constituents in this study were similar to those found in the literature. This study demonstrated peppermint can be successfully grown as an essential oil crop in Mississippi, and possibly the southeastern USA.
Technical Abstract: Peppermint (Mentha •piperita) is currently not a common crop in the southeastern United States. Recently, there has been an interest in peppermint as an essential oil crop for this region. In 2007, a 'eld experiment was conducted in Mississippi to determine the effect of nitrogen (N) (0 and 80 kg•ha–1), location (Verona and Stoneville), and harvesting stage (bud formation and 'owering) on peppermint pro¬ductivity, oil content, and composition. Peppermint biomass yields were higher at Verona (8.12 t•ha–1) than at Stoneville (6.12 t•ha–1). However, the essential oil content was higher at Stoneville (1.1%) than at Verona (0.6%). Generally, N rate at 80 kg•ha–1 did not affect oil yield and composition compared with 0 kg•ha–1. The concentrations of the major essential oil constituents were: (-)-menthol at 26% to 30%, (-)-menthone at 14% to 21%, (+)-menthofuran at 5% to 11%, and eucalyptol at 3% to 4% of total essential oil (wt/wt) and were generally within the values previously reported. The concentrations of (-)-menthone and (+)-menthofuran were signi'cantly higher at Stoneville, 21% and 11%, respectively, than at Verona (14% and 6%). The (-)-menthol, (-)-menthone, and (+)-menthofuran yields/ha were higher at Stoneville than at Verona. Overall oil content and yields were higher at bud formation than at 'owering, 1.3 and 1.8 times, respectively. In addition, the concentration of (-)-menthone and eucalyptol and the yields of (-)-menthone, (+)-menthofuran, and eucalyptol were higher at bud formation than at 'owering. The results from this study demonstrated peppermint can be successfully grown in Mississippi and provide essential oil yields and composition comparable to those in the northwestern United States, the traditional peppermint-growing region.