Effects of Exogenous Boron Fertilizer Application in Mentha Piperita L. on Yield and Total Phenolic Production

: Peppermint is a plant of high economic importance, with its homeland in the Mediterranean region, spread over wide areas around the world. Peppermint a perennial aromatic plant species is used especially as a spice plant with the ethereal oils and menthol, menthone, pulegone, carvone compounds in it, but it is also used in industrial areas such as food, cosmetics, and pharmaceutical industries. The research presented under the light of these determinations, the application of boron fertilizers in the form of spraying from the soil and the foliarly in plants belonging to the Mentha piperita L. species, which are economically grown as a spice and medicinal plant in the world, was carried out to determine the effects by the shoot length, fresh herb yield, dry herb yield, dry leaf yield, chlorophyll amounts, and on total phenolic accumulation. Sodium octaborate fertilizer (Na 2 B 8 O 13 .4H 2 O disodium octaborate tetrahydrate) at concentrations of 0, 5, 10, 15 mg L -1 was applied twice to the plants in the potting experiment. The results showed that sodium borate fertilizer, especially concentrations of 10 and 15 mg L -1 , significantly increased the yield parameters compared to the control application. It was determined that sodium borate fertilizer applications at concentrations of 5, 10, 15 mg L -1 increased total phenolic matter accumulation by 123.87%, 119.14%, and 136.02% respectively.