Effects of nitrogen nutrition upon the quality and yield of head chicory (Cichorium intybus L. var. foliosum)

Influence of nitrogen fertilization upon the quality and yield of head chicory (Cichorium intybus L. var. foliosum) was investigated for several years in field trials involving eight fertilizing variants. Investigation results indicate that nitrogen application influenced the differences in the contents of dry matter (4,23 - 5,30 %), plant nitrogen (3,33 - 4,95 % N) and crude proteins (N x 6,25). Dry matter phosphorus ranged between 1,20 and 2,11 % P2O5 while values from 4,25 to 5,68 % K2O were determined for potassium. Chicory yields varied from 1,29 to 2,6 kg/m(2) Head chicory quality, that is its overall nutritional value, was estimated relative to the quantity of essential mineral elements (calcium, magnesium, iron, zinc and copper) as well as some vitamins and essential amino acids. Red head chicory contains a particularly favorable quantity of calcium (20 mg Ca) and iron (1,5 mg Fe) in 100 g in fresh weight (F.W.). As regards vitamins, 14,06 mg of vitamin C and 0,32 mg of carotene were determined in 100 g of F.W.. A very high content of some essential amino acids, especially methionine, was recorded.