摘要 : Leaf analysis is an important tool to evaluate the nutritional status of crops. Evaluation of the nutritional status of the majority of crops generally involves a comparison of foliar nutrient concentrations with reference values ... 展开 Leaf analysis is an important tool to evaluate the nutritional status of crops. Evaluation of the nutritional status of the majority of crops generally involves a comparison of foliar nutrient concentrations with reference values associated mainly with yield and its quality. However, reference values for leaf-mineral composition are unknown for regional varieties. This study reports initial results of experiments in thirty vineyards of 'Trincadeira'/99R in Borba/Alentejo, one of the main producers of quality Portuguese wines. In each vineyard an experimental plot with forty plants was selected. From 2004 to 2007 the basal cluster opposite leaf of each grapevines was collected at full bloom, and N, P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu and B were determined in petioles. Grape yield and must quality were also evaluated. Preliminary interpretative indices for petioles-analysis were established based on the higher yielding vineyard of 'Trincadeira'. 收起