In pot experiments with lettuce, the effect of chelated and mineral forms of manganese on the fresh matter of plants and on the content of Mn, Cu, Zn and Fe in lettuce leaves were compared. Lettuce plants were grown in a peat substrate where the manganese content was differentiated in four levels: 10, 20, 30, and 60 mg Mn∙dm^-3. Independent of the form of the applied manganese, no differences were found in fresh matter of lettuce heads at manganese levels of 10 to 30 mg Mn∙dm^-3 substrate. When the plants were nourished with the mineral form of manganese, then in comparison with the chelated form of manganese, the content of manganese in lettuce leaves was higher. The differentiated fertilization with manganese exerted an effect on the nutritional status of plants with copper, zinc and iron. After the application of chelated manganese, there was more copper and iron in the lettuce, but a lesser amount of zinc than in case of manganous sulphate application. The increase of manganese content in the substrate caused an increase of this component in the plants.

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