Assessment of soil moisture stress induced variability in oil content and composition in mint species

In the delicate balance of plant vitality, moisture-stress emerges as a critical determinant. Its stifling impact on stomatal regulation and photosynthesis underscores its role in shaping agronomic outcomes and essential oil production. Addressing this challenge is imperative. Hence, the present investigation intended to find out the consequence of soil moisture on essential-oils content, and composition of three mint varieties. Experiment was setup with nine treatments from which the samples were collected at different times i.e., before and after irrigation. The study revealed noticeable variations in oil content across all species of mint family under increasing soil moisture stress. For instance, in M. spicata L., the oil content found between 0.37% and 0.57%, while in M. piperita L., it varied from 0.50% to 0.62%, and in M. citrata L., it spanned from 0.43% to 0.62% during the morning and afternoon measurements. The predominant compound in M. spicata L. was piperitone oxide (43.04%–80.94%), while M. piperita L. exhibited higher concentrations of menthol (31.30%–46.80%) and menthone (10.63%–26.48%). In contrast, M. citrata L. stood out as a notable source of linalool (0.0%–58.27%). These findings collectively indicate that variations in soil moisture-stress significantly impact both the quantity and composition of oils in these species.