Table 1.
Main practices used in the three experimented management systems in the 2011–2013 period.
Table 2.
Range of variation of dry matter (%), total soluble solid contents (°Brix), individual sugars (g kg-1 FW), titratable acidity (mmol H+ kg-1 FW), organic acids (g kg-1 FW) and phenolics (mg kg-1 FW) of apple samples from 3 management systems x 3 cultivars in 3 years.
Fig 1.
PCA results on mid-infrared spectral data of apple skin and pulp. A: spectral area between 1500–1000 cm-1, B: spectral area between 2000–1500 cm-1 and C: spectral area between 3000–2500 cm-1.
The code corresponds to the cultivar (M: Melrose, S: Smoothee, A: Ariane), to the management system (C: conventional, O: organic, L: low-input) and to the year 2011, 2012 and 2013.
Table 3.
Fisher’s F-values and significance associated with ANOVAs (management system, cultivar, year) performed on apple pulp metabolites, dry matter, and fruit weight.
Table 4.
Fisher’s F-values and significance associated with ANOVAs (management system, cultivar, year) performed on apple skin metabolites and dry matter.
Fig 2.
PCA results on individual sugars, organic acids, titratable acidity, dry matter, fruit weight, phenolics and total soluble solids of apple pulp. A: Correlation circle of variables loadings on PC1 and PC2. B: Sample map of scores on PC1 and PC2 as function of the cultivar. C: Sample map of scores on PC1 and PC2 as function of the year. D: Sample map of scores on PC1 and PC2 as function of the management system.
The code corresponds to the cultivar (M: Melrose, S: Smoothee, A: Ariane), to the management system C: conventional, O: organic, L: low-input), and to the year (2011, 2012 and 2013).
Fig 3.
PCA results on individual sugars, organic acids, titratable acidity, dry matter, phenolics and total soluble solids of the skin. A: Scatter plot of loadings on PC1 and PC2. B: Sample map of scores on PC1 and PC2 as function of the cultivar. C: sample map of scores on PC1 and PC2 as function of the year. D: Sample map of scores on PC1 and PC2 as function of the year.
The code corresponds to the cultivar (M: Melrose, S: Smoothee, A: Ariane), to the management system C: conventional, O: organic, L: low-input), and to the year (2011, 2012 and 2013).
Table 5.
Fisher’s F-values associated with two-way ANOVAs (management system and cultivar) performed on apple pulp and skin metabolites, dry matter, and fruit weight in 2011.
Fig 4.
Comparison of metabolite levels in the apple pulp and fruit weight as function of management system for variables with significant management system effects (P ≤ 0.05, Table 5) in 2011.
For each variable, values marked with the same letter do not differ significantly (P ≥ 0.05).
Fig 5.
Comparison of metabolite levels in the apple skin as function of the management system for variables with significant management system effects (P ≤ 0.05, Table 5) in 2011.
For each variable, values marked with the same letter do not differ significantly (P ≥ 0.05).
Fig 6.
Sum of total phenolics content in apple pulp for the years 2011 (A), 2012 (B), and 2013 (C) and in apple skin for 2011 (D), 2012 (E), 2013 (F) for fruit grown under conventional, low-input and organic management systems.
Values are means of three different samples analyzed independently.