Table 1.
Concentrations of Zn, Fe, Mn, Cu (mg kg–1 DW) and Ca, K, Mg, P (mg g–1 DW) in young, mature, and old leaves collected from healthy (CK) and HLB-affected grapefruit plantsOne or two asterisks represent the least significant differences (P <0.05 and P <0.01, respectively) between leaf samples on a healthy tree and a sample with the corresponding age from an HLB-affected tree. Data points represent means from three individual plants.
| Plant samples | Zn | Fe | Mn | Cu | Ca | K | Mg | P | |
|---|---|---|---|---|---|---|---|---|---|
| mg kg–1 DW | mg g–1 DW | ||||||||
| CK | Young | 34.6±4.5* | 73.7±9.6 | 73.0±4.1* | 16.7±2.0** | 12.0±1.3 | 1.48±0.08 | 2.32±0.35 | 12.3±1.1 |
| Mature | 38.7±2.6* | 67.9±8.7 | 66.8±8.6 | 11.9±1.8 | 13.2±1.5 | 1.62±0.08 | 2.71±0.27 | 14.6±0.9 | |
| Old | 42.4±5.1* | 78.8±9.1 | 87.9±8.1 | 17.9±4.3 | 26.3±2.7 | 2.23±0.13 | 3.86±0.84 | 11.5±0.9* | |
| HLB | Young | 24.1±2.9 | 71.4±8.6 | 51.0±6.2 | 8.9±1.5 | 14.5±1.2 | 1.31±0.21 | 2.66±0.13 | 14.9±1.3 |
| Mature | 26.7±3.1 | 70.6±6.4 | 52.6±5.8 | 9.5±3.2 | 14.3±1.4 | 1.27±0.10 | 2.37±0.13 | 13.4±1.1 | |
| Old | 32.8±4.3 | 86.2±8.7 | 80.7±7.5 | 15.1±2.5 | 28.7±3.7 | 1.89±0.19 | 5.08±0.62 | 8.5±0.9 | |