Thyme (Thymus vulgaris L.) is an important cultural aromatic plant, whose essential oils (EOs) have been used in many industrial applications. EO yields are often negatively influenced by various factors, so it is important to keep finding new growing procedures that increase the quantitative content of EOs. Therefore, this paper is focused on the effects of applying foliar nutrition, including N, P and K in combination with salicylic acid (SA), on selected yield characteristics related to the quantitative and qualitative content of EOs in T. vulgaris plants.
As shown by our field experiments, targeted pre-harvest application can significantly increase the yield of EOs, resulting in a quantitative increase in the EO content of the plants, ranging from 18.76% to 42.47% compared to untreated plants. In addition, EOs obtained from the treated plants were found to contain 62.1–64.1% thymol; this range was more stable compared to untreated plants, where the thymol content ranged between 53.1% and 62.7%.