| Popis: |
Background and Aims: This study reports on the effects that timing of saline irrigation has on leaf and wood tissue concentrations of Na+ and Cl– and on juice composition. Methods and Results: Colombard vines on Ramsey rootstock were drip irrigated with saline water during any one of four annual growth stages: pre-flowering, berry formation, berry ripening and postharvest. At other times, vines were irrigated with non-saline water as was the control. Salts were annually flushed from the rootzone. Over six seasons, saline irrigation caused five- and sevenfold rises, respectively, in the leaf and juice Na+ concentrations and two- and fourfold rises in respective Cl- concentrations. Saline irrigation raised juice pH and this was associated with a rise in juice Na+. Normalising responses for inter-treatment differences in the seasonal salt load to isolate the effects of timing showed that juice Cl- concentration was most sensitive to saline irrigation during berry formation and juice malate concentration most sensitive to saline irrigation pre-flowering. Conclusion: Cl- uptake was greatest when saline irrigation was applied early in organ formation, whereas Na+ uptake reflected seasonal salt load in irrigation water. Significance of the Study: In vines on the chloride excluding rootstock Ramsey, yield loss under saline irrigation was associated with high concentrations of sodium in the leaf. |
