Impact of synthetic films and organic mulches on yield and quality of Mentha piperita L. essential oil

The study investigates the influence of organic mulches and synthetic films on the yield and quality of essential oil in Mentha piperita L. over two consecutive years in Southeast Europe. The field two-factorial randomized complete block design experiment utilized the "Mitcham" cultivar of M. piperita , assessing effect of six treatments: two organic mulches (sawdust of acacia and dry pine needles), two synthetic films (black agrotextile film and silver-brown film), and two controls (weeded and non-weeded), conducted in Pančevo, South Banat, Serbia. The study examined the effects on these treatments on the yields of plant material (stems and leaves with flowers), as well as the yield and composition of essential oil (leaves with flowers). The plants were harvested at the optimal phase, when the flowers in the first third of the inflorescence were fully open. The results showed that application of mulches and films significantly increased the yield of leaves with flowers compared to the non-weeded control, with synthetic films generally outperforming organic ones. When the controls are omitted, M. piperita cultivated on silver-brown film (2.8 t ha −1 ) and black agrotextile film (3.0 t ha −1 ) achieved the highest yields, resulting in exceptionally high essential oil production. The essential oil yield varied from 5.88 % to 7.50 % in treatments with synthetic films, whereas in non-weeded and weeded controls, it was 4.64 % and 7.13 %, respectively. In addition to prominent synthetic films, organic dry pine needles increased the yield and quality of essential oils, indicating that they could be used to improve the outcomes of cultivated M. piperita . Significant variations were also observed in the chemical composition of M. piperita essential oils, particularly in the levels of menthol, menthone, and other monoterpenes • Mentha piperita herb yield influenced by organic mulches and synthetic films. • Ground covers affect menthol and menthone content in Mentha piperita essential oil. • Synthetic films are recommended for highest herb and essential oil yields.