Table 2.
Analysis of variance and mean comparisons for shoot fresh weight, dry weight of shoots and roots, total root length, average root diameter, and total root surface of lettuce plants grown with different nutrient solutions and biostimulants.
| Source of variance | Shoot fresh weight (g/plant) | Shoot dry weight (g plant-1) | Root dry weight (g plant-1) | Total root length (m plant-1) | Root diameter (mm) | Total root surface (cm2 plant-1) |
|---|---|---|---|---|---|---|
| Nutrient solution (N) | ∗∗∗ | ∗∗ | ∗ | ∗∗∗ | ns | ∗∗ |
| Biostimulant (B) | ∗∗∗ | ∗∗∗ | ∗∗ | ∗∗ | ns | ∗ |
| N × B | ns | ns | ∗ | ns | ns | ns |
| Nutrient solution | ||||||
| Standard | 175.4ˆa | 7.81ˆa | 1.86 | 531.4ˆa | 0.29 | 48.4ˆa |
| Alkaline | 161.6ˆa | 7.87ˆa | 1.79 | 484.1ˆb | 0.30 | 44.5ˆab |
| Saline | 119.4ˆb | 7.02ˆb | 1.55 | 405.1ˆc | 0.28 | 37.0ˆb |
| Biostimulant | ||||||
| No application | 122.2ˆc | 6.03ˆb | 1.47 | 436.8ˆc | 0.28 | 40.5ˆc |
| Tablet | 155.2ˆb | 8.06ˆa | 1.75 | 470.4ˆb | 0.29 | 42.7ˆb |
| Tablet + PH | 179.2ˆa | 8.62ˆa | 1.98 | 510.1ˆa | 0.29 | 46.5ˆa |
| N × B | ||||||
| Standard solution without biostimulant | 145.8 | 5.93 | 1.63ˆbc | 494.1 | 0.29 | 45.8 |
| Standard solution + Tablet | 171.5 | 8.45 | 1.84ˆab | 538.5 | 0.29 | 48.7 |
| Standard solution + Tablet + PH | 209.1 | 9.05 | 2.12ˆa | 561.6 | 0.30 | 50.6 |
| Alkaline solution without biostimulant | 132.7 | 6.53 | 1.48ˆcd | 460.4 | 0.29 | 43.2 |
| Alkaline solution + Tablet | 166.0 | 8.37 | 1.81ˆab | 472.0 | 0.30 | 43.3 |
| Alkaline solution + Tablet + PH | 186.3 | 8.72 | 2.08ˆa | 519.8 | 0.30 | 47.1 |
| Saline solution without biostimulant | 88.0 | 5.62 | 1.31ˆd | 355.9 | 0.27 | 32.6 |
| Saline solution + Tablet | 128.0 | 7.36 | 1.61ˆbc | 400.8 | 0.29 | 36.1 |
| Saline solution + Tablet + PH | 142.3 | 8.09 | 1.74ˆbc | 458.6 | 0.28 | 42.4 |
ns, ∗, ∗∗, ∗∗∗ Non-significant or significant at P ≤ 0.05, 0.01, and 0.001, respectively. Different letters within each column indicate significant differences according to Duncan’s multiple-range test (P = 0.05). Tablet = microbial-based biostimulant ‘Click Horto’ containing 200 spores/tablet of R. irregularis BEG72 plus 4.5 × 107 CFU/tablet of T. atroviride MUCL45632; PH = plant derived-protein hydrolysate ‘Trainer.’