Abstract

As a product of secondary metabolism, essential oils may exhibit variation in their composition according to mode of plant cultivation. The application of organic manure has been considered one of the key factors for increasing biomass and essential oil production in most of medicinal plants, as it provides nutrients and increases their uptake. This study aimed to evaluate the influence of organic fertilizer and lime doses on the biomass production of Mentha arvensis, as well as the content, yield and chemical composition of its essential oil. The experiment was conducted in a greenhouse and was performed according to a double factorial design consisting of four doses of dolomitic limestone (0.0, 0.25, 2.0 and 3.72 g dm-3, corresponding to a pH of 4, 5, 6 and 7, respectively) and five doses of the organic compost (0, 5, 10, 20 or 40 g dm-3) with ten replicates. There was an interaction between organic fertilization and liming for biomass production, with maximum leaf biomass averaged 8.61 g plant-1 and essential oil yield with application of 26 to 29 g dm-3 of organic compost and 1.7 to 2.0 g dm-3 of limestone into soil. Neo-iso-menthol was the major component of the M. arvensis essential oil.

Key words: Limestone, organic manure, neo-iso-mentol, Japanese mint, organic production.