Effect of Vanadium on Dry matter and Nutrient Concentration in pennyroyal (Mentha pulegium L)

An experiment was conducted in pots under glasshouse conditions to study the effects of Vanadium (V) on dry matter and on V, Ca, K, Mg, P, Fe, Mn, Ni, Pd, and Zn concentration in leaves, stems and roots of pennyroyal (Mentha pulegium L.). A completely randomized block design with five V treatments (0, 5, 10, 20, 40 mg L super(-1)) and six replications per treatment was laid out. Vanadium was applied to the pot medium (peat soil mixture) as NH sub(4) VO sub(3). No visible toxic or inhibitory symptoms were observed on the plants due to the increasing rates of V. Results indicated that root dry matter increased in plants receiving 10, 20 and 40 mg V L super(-1). The vanadium concentration in leaves and stems increased in plants receiving 20 mg V L super(-1), and 20 and 40 mg V L super(-1), respectively. The vanadium concentration in the leaves was always much lower than in roots and stems indicating that V accumulated mainly in roots and stems and only small quantities were transferred to the leaves. The results indicated that the Ca, K, Mn, and Zn concentrations in the roots were not affected by V additions. A reduction of Ca, K, Mg, and Mn concentration was observed in leaves at high V application rates.