Table 2 Influence of pre-bloom (PB) and veraison defoliation (V) on agronomic parameters, ripening parameters, and the flavonol and anthocyanin content of Sangiovese berries compared to non-defoliated controls (C) at harvest

Agronomic parameters

Yield/vine (kg)

6.3 a

4.4 b

5.5 a

Cluster number/vine

16

16

16

Cluster weight (g)

394 a

280 b

343 a

Berry weight (g)

2.37

2.26

2.33

Berry number/cluster

166 a

124 b

147 a

Cluster compactness (OIV rating)

7.5

6.8

7.8

Bunch rot/cluster (%)

5

2.1

2.3

Sunburn damage/cluster (%)

0.36 b

1.24 b

6.45 a

Leaf area/yield (m²/kg)

0.6 b

0.8 a

0.5 b

Berry skin thickness (μm)

232.3 b

255.6 a

223.8 b

Ripening parameters

°Brix

20.8 b

22.2 a

20.7 b

TA (g/L)

7.6 a

6.8 b

6.7 b

pH

3.38 b

3.45 a

3.45 a

Flavonols

Total flavonols (mg/g of skin)

0.32 b

0.71 a

0.67 a

Quercetin (%)

79.5 b

83.3 a

84.5 a

Myricetin (%)

17.7 a

11.4 b

10.5 b

Kaempferol (%)

2.8 b

5.3 a

5.0 a

Anthocyanins

Total anthocyanins (mg/g of skin)

4.87 ab

5.35 a

4.33 b

Delphinidin-3-G (%)

15

15.3

15.2

Cyanidin-3-G (%)

28.7 b

32.8 ab

42.3 a

Petunidin-3-G (%)

14.5

14

12.2

Peonidin-3-G (%)

13.5

14.3

13.1

Malvidin-3-G (%)

28.3 a

23.6 ab

17.2 b

3^′4^′-OH anthocyanins (%)

42.2 b

47.1 ab

55.3 a

3^′4^′5^′-OH anthocyanins (%)

57.8 a

52.9 a

44.7 b