Effects of the Annual Nitrogen Fertilization Rate on Vine Performance and Grape Quality for Winemaking: Insights from a Meta-Analysis

Table 4

Mean plus 95% confidence interval for the coefficients of the logistic curves fitted to the concentration of anthocyanins and the total polyphenol index.

Normalized parameter	Na (g·plant^−1)	k	b	q
Anthocyanins concentration	(0 ± 5) 10^−4a	66 ± 10^a	0.32 ± 0.26^a	90 ± 280^a
Total polyphenol index	(0 ± 4) 10^−9a	76 ± 6^a	0.22 ± 0.12^a	110 ± 300^a

For each curve coefficient, the means sharing at least one letter are nonsignificantly different at the 95% confidence level.