Response of Peppermint to Salt Stress

The effect of salt stress on the growth and essential oil production of peppermint (Mentha x piperita L.) was evaluated in this study. Accessions of peppermint, sourced from the National Clonal Germplasm Repository in Corvallis, Oregon, U.S.A., were grown in controlled environmental conditions to determine the variability for growth and oil constituents, and plantings of peppermint were subjected to a salt stress in containers and in a desert agrosystem. After 60 days growth, the accessions differed significantly in fresh weight yield, oil levels, and oil constituents, indicating considerable variability within the genome. Peppermint plants grown in containers and subjected to salt stress (1.5 g L-1) had 30% less fresh weight and a 34% lower oil yield than control plants not subjected to salt stress. In a desert environment, plants subjected to stress (EC = 2.87 dS m(-1)) had a more rapid growth rate (5.35 g plant(-1) day(-1)) than container grown plants (1.34 g plant(-1) day(-1)) under stress. Menthol, iso-menthyl acetate, and p-menthone were the major constituents of the peppermint. The results indicated that peppermint could be successfully grown in a desert environment and that the variability among peppermint accessions would allow selection of plants suitable for the growth environment.