MORPHOLOGICAL AND QUALITATIVE CHARACTERIZATION OF GLOBE ARTICHOKE (Cynara scolymus L.) CULTIVARS ‘SYMPHONY’ AND ‘MADRIGAL’ ON DEPENDING OF THE HEADS GROWTH

An artichoke is a commonly cultivated vegetable in the Mediterranean region. It is cultivated for an immature flower head. In Poland the artichoke is cultivated as an annual plant because of its high temperature demands. It is difficult to determine the most optimal harvest stage and the most often it is based on expensive chemical analysis. In the years 2007–2009 there was a research undertaken to specify the most optimal harvest stage of flower heads. In order to determine a development stage of head the height of flower bud in the middle part of the receptacle was measured directly after harvest. The unit weight of each head, the level of bracts deflection, content of dry weight, L-ascorbic acid, raw protein, raw fibre and total sugars in whole heads and their fractions: receptacle and bracts were determined. On the basis of obtained results it was stated that the size of flower buds on an inflorescence axis is a sign of full synchronization of head developmentand changing environmental conditions during artichoke vegetation. The edible part of artichoke, a receptacle, had more dry weight, total sugars, L-ascorbic acid and raw protein and less raw fibre in comparison to inner bracts. The increase of flower buds height on receptacle was accompanied with the increase of dry weight, raw fibre and total sugars content in heads and its fractions. The longer flower buds in the middle part of inflorescence the lower content of total protein in whole heads and bracts and the higher content of this component in receptacle. It was stated that the size of flower buds was negatively correlated with content of L-ascorbic acid as with the increase of flower buds height in receptacle the content of L-ascorbic acid in whole heads and it’s fractions decreased. The obtainedresults show that the level of bracts deflection may the selection indicator to determine harvest maturity. This feature of artichoke head allows to visually determine its harvest usability. Receptacles of Symphony content more dry matter, total protein and less total sugars than those of Madrigal. Intermediate values were found in Symphony and Madrigal for L-ascorbic acid and crude fibre.