Table 3.
Influence of irrigation on yield components and vegetative growth at harvest under two crop load levels during the 2014–2016 seasons. R: rainfed; I: unrestricted irrigation; H: high crop load; L: low crop load.
| Treatment | |||||||
|---|---|---|---|---|---|---|---|
| Year | Parameter | RH | IH | % Variation | RL | IL | % Variation |
| 2014 | Leaf area (LA, m2·vine−1) | 1.68 a | 2.84 a | 69.05 | 2.85 a | 2.93 a | 2.81 |
| Cluster number (CN) | 15.18 b | 17.05 b | 12.32 | 9.30 a | 10.95 a | 17.74 | |
| Cluster weight (CW, g) | 186.71 a | 196.68 a | 5.34 | 194.09 a | 234.36 a | 20.75 | |
| Berry weight (BW, g) | 1.87 a | 1.91 a | 2.14 | 2.30 c | 2.07 **b | −10.00 | |
| Yield (Y, kg·ha−1) | 9830 a | 10864.2 a | 10.52 | 6093 a | 8413.80 a | 38.09 | |
| Leaf area/yield (LA/Y, m2·kg−1) | 5.60 ab | 4.74 a | −15.36 | 10.64 a | 5.55 b | −47.84 | |
| 2015 | Leaf area (LA, m2·vine−1) | 1.98 b | 4.77 a | 140.91 | 1.44 b | 2.87 ab | 99.31 |
| Cluster number (CN) | 12.83 b | 15.33 c | 19.49 | 8.30 a | 10.45 a | 25.90 | |
| Cluster weight (CW, g) | 192.77 c | 267.47 **ab | 38.75 | 240.82 bc | 313.77 *a | 30.29 | |
| Berry weight (BW, g) | 1.50 d | 1.72 ***b | 14.67 | 1.57 c | 1.78 ***a | 13.38 | |
| Yield (Y, kg·ha−1) | 8243.30 b | 13744.20 *a | 66.73 | 7295.8 b | 10837.50 *ab | 48.54 | |
| Leaf area/yield (LA/Y, m2·kg−1) | 5.08 ab | 9.53 a | 87.60 | 4.84 b | 5.97 ab | 23.35 | |
| 2016 | Leaf area (LA, m2·vine−1) | 2.10 b | 4.68 a | 122.86 | 1.78 b | 2.80 ab | 57.30 |
| Cluster number (CN) | 12.73 ab | 15.05 a | 18.22 | 8.25 c | 11.65 *b | 41.21 | |
| Cluster weight (CW, g) | 126.61 ab | 153.31 a | 21.09 | 90.40 b | 175.65 **a | 94.30 | |
| Berry weight (BW, g) | 1.04 a | 1.41 **c | 35.58 | 1.19 b | 1.47 **c | 23.53 | |
| Yield (Y, kg·ha−1) | 4937.50 ab | 6317.5 a | 27.95 | 2186.70 b | 6068.30 *ab | 177.51 | |
| Leaf area/yield (LA/Y, m2·kg−1) | 9.26a | 12.09 a | 30.56 | 8.83 a | 5.15 a | −41.68 | |
*, ** and *** indicate, for the same crop load (H/L), the significance of irrigation treatment rainfed vines in respect to irrigation at p < 0.05, p < 0.01 and p < 0.001, respectively. For each parameter, means followed by different letters were significantly different between treatments, p < 0.05, Tukey’s HSD test.