Impact of Cluster Thinning on Wine Grape Yield and Fruit Composition: A Review and Meta-Analysis
Table 2
Impact of cluster thinning timing on production and fruit composition variables.
Parameter
Bloom (B)
Pea-size (PS)
Lag phase (LP)
Veraison (V)
value (trt)c
CNb
CT
CN
CT
CN
CT
CN
CT
Production parameters
Yield (kg/vine)
4.18 ± 0.376
4.39 ± 0.460
3.07 ± 0.347
4.19 ± 0.381
2.82 ± 0.267
4.23 ± 0.255
2.72 ± 0.168
<0.001
Leaf-area/yield (cm2/g)
15.4 ± 2.06
22.6 ± 3.11
17.8 ± 2.95
29.4 ± 5.78
15.0 ± 1.54
22.8 ± 1.85
13.9 ± 0.974
22.2 ± 1.59
0.003
Berry weight (g)
1.42 ± 0.041
1.47 ± 0.043
1.42 ± 0.038
1.45 ± 0.040
1.55 ± 0.062
1.59 ± 0.061
1.45 ± 0.038
1.44 ± 0.041
0.234
Fruit composition parameters
Total soluble solids (°Brix)
22.0 ± 0.276
22.5 ± 0.250
22.0 ± 0.230
22.6 ± 0.234
23.2 ± 0.318
24.1 ± 0.261
22.5 ± 0.185
23.4 ± 0.167
<0.001
pH
3.45 ± 0.041
3.49 ± 0.041
3.42 ± 0.025
3.48 ± 0.026
3.46 ± 0.051
3.54 ± 0.056
3.47 ± 0.022
3.53 ± 0.022
0.065
Titratable acidity (g/L)
5.94 ± 0.430
5.98 ± 0.444
7.22 ± 0.261
7.10 ± 0.261
6.22 ± 0.293
5.94 ± 0.270
6.23 ± 0.216
5.97 ± 0.199
0.802
Total anthocyanins (mg/kg) FW berry
1404 ± 60.9
1567 ± 86.7
1251 ± 192
1347 ± 177
748 ± 194
902 ± 253
1259 ± 124
1469 ± 124
0.445
Total anthocyanins (mg/L)
76.8 ± 8.49
81.9 ± 4.87
549 ± 169
570 ± 167
292 ± 30.2
336 ± 20.9
891 ± 87.2
1081 ± 122
0.307
Total phenolics (mg/kg) skin FW
—
—
1740 ± 371
2094 ± 570
1325 ± 702
1471 ± 847
2110 ± 219
2789 ± 101
0.584
Total phenolics (mg/L)
954 ± 91.2
996 ± 167
2159 ± 126
2291 ± 104
4553 ± 179
4974 ± 169
1192 ± 325
1289 ± 325
0.725
aData are expressed as means ± standard error. Bold values highlight significant difference () between CN and CT treatments within each timing (B, PS, LP, or V) using an independent-samples t-test. bCN, untreated control; CT, cluster thinning. cComparison between CN and CT treatments using data from all time points ().
