Molybdenum is a fundamental trace element in the nutrient supply of crops. The crop physiological importance of molybdenum was revealed in 1940. This element has an important role in the nitrogen metabolism of crops, molybdenum shortage is accompanied by nitrate accumulation.

This research work had a dual aim:

The purpose of these experiments was to examine how Mo, Fe and S concentrations change in maize (Zea mays L. cv. Norma SC) seedlings as a result of increasing Mo concentration. The reason it was considered to be important to trace the concentrations of these three elements is that they have special roles in nitrate reduction and the functioning of nitrate reductase. Furthermore, these experiments helped to show under laboratory conditions that there is a close correlation between molybdenum supply and nitrate reduction: crops’ nitrate content can be reduced while providing their physiological molybdenum need.

These experiments can be classified into the two following groups: rhizobox and culture medium experiments.

Three different concentrations of Mo were used in the rhizobox experiments: 30, 90, 270 mg kg-1. No molybdenum was added to the control soil.

The following treatments were used in the culture medium experiments: 0,01 μM, 0,1 μM, 1 μM Mo. The control culture medium did not contain any molybdenum.

It can be clearly seen from the results that the Mo concentration of maize seedlings significantly increased as a result of Mo treatments. Based on the separate examination of the shoots and roots of the experimental crops, it was established that Mo concentrations measured in the roots are higher than those of the shoots. This phenomenon refers to the fact that nitrate accumulation was more intensive in the roots under the examined conditions. As opposed to molybdenum, no obvious and significant increase was observed in the concentration of sulphur and iron.

Keywords: molybdenum, maize, rhizobox, culture medium