Analysis of Vine Nutrition and Productivity Based on Statistical Indicators

Different fertilization systems, methods and techniques result in differences in plant nutrition, with variations in the mineral element contents in the leaves and values of physiological, yield, and production quality indices. This results in large datasets that are often relatively difficult to interpret. Starting from these aspects, the present study analyzed data on the state of plant nutrition (N, P, K, Ca, and Mg content in leaves, in % of dry matter; Fe, Mn, Cu, and Zn content in leaves, in mg/kg of dry matter), physiological indices (chlorophyll leaf content—Chl; leaf area—LA), yield (kg/vine, t/ha), and grape berry quality (sugar and acidity content in berries) of the ‘Burgund mare’ grape cultivar in relation to organic, mineral and foliar fertilization. According to a PCA multivariate analysis, four groups of components were obtained: PC1 including five factors, with positive action in the case of K (r = 0.963), P (r = 0.770) and Cu (r = 0.752), and negative action in the case of Mg (r = −0.940) and Mn (r = −0.759); PC2 including three factors, with positive action for Chl (r = 0.938), LA (r = 0.938) and Ca (r = 0.722); PC3 including one factor (N), with negative action (r = −0.916); and PC4 including two factors, with positive action for Fe (r = 0.869) and Zn (r = 0.761). Based on the one-sample t test (parametric) and the Wilcoxon test (non-parametric) and a threshold value of α = 0.05, the differences between the index values for fertilization variants T2–T13 compared with those for the control variant (T1) were verified. Significant differences were recorded in PC1 for P, Mg and Cu; in PC2 for Chl, LA and Ca; and in PC3 for N. Insignificant differences were recorded in PC1 for K and Mn and in PC4 for Fe and Zn. In the case of the productivity elements and quality indices, significant differences were recorded.