The influence of the composition of peat mixtures on the biochemical parameters of Melissa officinalis plants

Abstract

In the course of a model experiment, the influence of the composition of peat mixtures from sand, lowland peat and soddy-podzolic sandy loamy soil on the content of polyphenols, photosynthetic pigments, the amount of antioxidants and malondialdehyde in the leaves of lemon balm medicinal variety “Limonnyy aromat’’ was studied. It has been established that the most optimal compositions of peat mixtures for growing plants of lemon balm are compositions with the following ratios of components: 1st mixture – soil 1 part + sand 2 parts + peat 2 parts; 2nd mixture – soil 1 part + sand 3 parts + peat 1 part. When growing plants on these mixtures, there is a greater accumulation of biologically active substances (phenolic compounds, photosynthetic pigments, antioxidants), a decrease in the content of the oxidative stress marker – malondialdehyde compared to soil and peat, as well as to a variant with a high content of peat (soil 1 part + sand 1 part + peat 3 parts). The addition of fertilizer “SOLAR UNIVERSAL – 18:18:18 + 3MgO + ME” to 1st peat mixture has proven itself well, especially at a dose of 1 mL per 50 g of substrate (fertilizer concentration 2 g/L). With the introduction of such a dose of fertilizer into peat mixture, the maximum values of the content of photosynthetic pigments and antioxidants in lemon balm leaves were noted. The above variants of peat mixtures can be recommended for use as soils for growing lemon balm both at home and on an industrial scale.