Table 3.
Grape berry skin flavonoid concentration at harvest in a Merlot (Vitis vinifera L.) vineyard in Denair, California in 2014 and 2015 a,b,c.
| Anthocyanins | Flavonols | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2014 | ||||||||||||
| Delphinidin | Cyanidin | Petunidin | Peonidin | Malvidin | Tri-hydroxylated | Di-hydroxylated | Total anthocyanins | Quercetin | Myricetin | Total flavonols | ||
| LR | Control | 11.06 a | 6.56 a | 11.94 a | 17.32 | 94.05 | 117.05 | 23.88 ab | 140.93 | 13.33 | 0.73 | 14.06 |
| PBLR | 8.32 b | 5.45 b | 9.57 b | 15.56 | 85.70 | 103.59 | 21.01 b | 124.60 | 13.09 | 0.85 | 13.94 | |
| PFLR | 11.19 a | 7.25 a | 12.01 a | 18.86 | 90.52 | 113.72 | 26.11 a | 139.83 | 15.00 | 0.88 | 15.88 | |
| p value | ** | * | ** | ns | Ns | ns | * | ns | ns | ns | ns | |
| IRRI | SDI | 9.28 b | 6.73 | 10.43 b | 18.08 | 81.71 | 101.43 b | 24.81 | 126.24 b | 13.54 | 0.80 | 14.34 |
| RDI | 11.10 a | 6.11 | 11.91 a | 16.39 | 98.56 | 121.57 a | 22.50 | 144.07 a | 14.09 | 0.84 | 14.93 | |
| p value | * | ns | * | ns | ** | ** | ns | ** | ns | ns | ns | |
| LR × IRRI | ns | ns | ns | ns | Ns | ns | ns | ns | ns | ns | ns | |
| 2015 | ||||||||||||
| LR | Control | 7.89 | 5.29 | 8.92 | 16.67 | 70.46 b | 87.27 b | 21.96 | 109.23 | 4.89 b | 1.71 b | 7.81 b |
| PBLR | 8.47 | 5.65 | 9.35 | 18.28 | 70.88 ab | 88.70 b | 23.93 | 112.64 | 6.35 ab | 1.88 b | 9.69 ab | |
| PFLR | 8.91 | 5.76 | 10.33 | 18.44 | 85.96 a | 105.20 a | 24.21 | 129.40 | 7.41 a | 2.36 a | 11.53 a | |
| p value | ns | ns | ns | ns | * | * | ns | ns | ** | * | ** | |
| IRRI | SDI | 8.19 | 5.60 | 9.31 | 17.63 | 74.46 | 91.96 | 23.24 | 115.19 | 6.17 | 1.96 | 9.58 |
| RDI | 8.66 | 5.53 | 9.76 | 17.96 | 77.08 | 95.49 | 23.49 | 118.98 | 6.27 | 2.02 | 9.78 | |
| p value | ns | ns | ns | ns | Ns | ns | ns | ns | ns | ns | ns | |
| LR × IRRI | ns | ns | ns | ns | Ns | ns | ns | ns | ns | ns | ns | |
| Year | ** | * | * | ns | *** | *** | ns | ** | *** | *** | *** | |
| Year × LR | * | ns | ns | ns | Ns | ns | ns | ns | ns | ns | ns | |
| Year × IRRI | ns | ns | ns | ns | * | ns | ns | ns | ns | ns | ns | |
| Year × LR × IRRI | ns | ns | ns | ns | Ns | ns | ns | ns | ns | ns | ns | |
a ANOVA to compare data (p value indicated); Letters within columns indicate significant mean separation according to Tukey’s honestly significant difference test at p value ≤ 0.05, where “*”: p value ≤ 0.05; “**”: p value ≤ 0.001; “***”, p value ≤ 0.0001. b All compounds were expressed as mg per kg of berry fresh weight. c Abbreviations: LR: leaf removal; IRRI: irrigation; PBLR: prebloom leaf removal; PFLR: post-fruit-set leaf removal; SDI: sustained deficit irrigation; RDI: regulated deficit irrigation, ns: not significant.