NITRATE CONTENT OF THE EDIBLE PARTS OF VEGETABLES AND SPICE PLANTS

Abstract. The objective of a study conducted in the years 2007–2008 was to determine the nitrate content of the edible parts of vegetables and spice plants. The analyzed materi-als consisted of the following species: tomatoes, carrots, sweet basil and marjoram grown in the field, and tomatoes and chili peppers grown in a plastic tunnel. The experiment comprised different cultivation methods, sowing and planting dates, and fertilization lev-els. Among the analyzed cultivars of field-grown tomatoes, increased nitrate concentra-tions were observed in the fruits of cv. Złoty Ożarowski. Similar results were noted when eight tomato cultivars were grown in an unheated plastic tunnel. The fruits of cv. Bawole Serce had the lowest nitrate content, compared with the remaining tomato cultivars. Sup-plemental fertilization of tomato plants grown under cover significantly contributed to ni-trate accumulation. The fruits of chili peppers grown in a plastic tunnel had a very low ni-trate content. As regards marjoram, the highest nitrate concentrations were reported for the second date of sowing. The average nitrate content of carrot storage roots did not ex-ceed the maximum permissible levels. Supplemental fertilization contributed to an insig-nificant increase in the N-NO3 content of carrot roots