Nitrogen Distribution in Annual Growth of ‘Italia’ Table Grape Vines

Little information is available about either nitrogen (N) content/concentration in table grape vines. The knowledge about N accumulated by the vine organs during the season could support sustainable fertilization programs for table grape vineyards. The aim of the present paper was to investigate the N content in different annual organs, in summer and winter pruning materials, clusters at harvest and fallen leaves at post-harvest of table grape vines in order to verify the vine annual N requirements to be used for sustainable N fertilization schedules. Biomass and nitrogen were analyzed at six phenological growth stages (flowering, berry-set, berry growth, veraison, ripening, and harvest) fr…