Studies in the mineral nutrition of Japanese mint

Summary Potassium deficiency resulted in a increased accumulation of total phosphorus, inorganic phosphorus and sugar phosphate which suggested some interference in phosphorus metabolism predominantly beyond the sugar phosphate synthesis stage. Roots appeared to be a reservoir for accumulation of various phosphorus fractions of Japanese mint (Mentha arvensis L. var.piperascens).A higher respiration rate under potassium deficiency might be one of the factors to retard the inclusion of inorganic phosphorus into structural components, resulting in poor formation of organophosphorus compounds needed for plant growth and development. In spite of an increased essential oil content (ml/100 g dry weight) in a phosphorus deficient situation, total essential oil production (ml/plant) was low. Foliage growth, essential oil content and respiration was higher between 60 to 80 days and seemed to be associated with a high intensity of enzymatic and metabolic activity, as observed in various phosphorus fractions rising to a very high value after 80 days of crop growth.