CORRELATION BETWEEN YIELD, MUST ATTRIBUTES AND NUTRITIONAL STATUS OF THE GREEK RED WINE GRAPE VARIETY 'AGIORGITIKO'

The appropriate tissue and sampling time for the Greek wine-grape variety 'Agiorgitiko' nutritional diagnosis was to be evaluated by relating leaf tissue nutrient contents with the yield and must potassium (K), pH, total soluble solids (TSS), and titratable acidity (TA). At bloom, veraison and harvest, leaves opposite the basal cluster (LOBC) and youngest mature leaves (YML) were harvested, and soil and berry samples were collected from six vineyards in Nemea, Greece. Petiole K concentration of the LOBC was found to be better correlated with the yield, TSS, TA and must K than the blade or whole leaf K content; the contrary was observed in nitrogen (N), phosphorus (P), calcium (Ca), and magnesium (Mg) concentrations. The LOBC reflected better the nutritional status of the variety compared to the YML. Regarding the sampling time, petiole K presented stronger correlations with yield and must K, TSS, TA at harvest whereas N and P at bloom and veraison.