Influence of Salt Stress on the Nutritional State of Cordyline fruticosa var. Red Edge: Chloride, Nitrogen, and Phosphorus

Abstract

This trial was carried out to study the nutritional and productive behavior generated by modifications in the salt concentration in the nutrient solution for Cordyline fruticosa var. Red Edge plants. The anions studied were chloride (Cl), nitrogen (N), and phosphorus (P). Four treatments were tested: T₁ [control, 1.5 dS m⁻¹, 14.3 mmol L⁻¹ sodium chloride (NaCl)], T₂ (2.5 dS m⁻¹, 22.2 mmol L⁻¹ NaCl), T₃ (3.5 dS m⁻¹, 32.7 mmol L⁻¹ NaCl), and T₄ (4.5 dS m⁻¹, 38.2 mmol L⁻¹ NaCl). At the end of the cultivation, leaf, petiole, shoot and root fresh and dry weights, elemental extractions, and elemental concentrations were determined. Nutrient concentrations and total plant uptake (extraction) were calculated from the dry matter. The treatment T₂ induces a blade protection mechanism, which consists on the accumulation of chloride (Cl⁻) in root and vessels; so, leaf storage is reduced, avoiding damages. Petiole also contributes to this protection, acting as a salt pool. As NaCl concentration in the nutritive solution arises, N plant concentration increases significantly although there are no significant differences between T₁ and T₂. With high salinity levels, P in vessels is reduced, whereas root extraction and concentration increases. The greatest N and P extractions are observed in T₂, which is due to its higher dry matter. Chloride extractions are lower in T₁ than in the other treatments.

Keywords:

• Anion partitioning
• CE
• osmotic potential
• salinity

Acknowledgments

The first author is funded by a FPU grant from the MICINN (AP2007–02786) at the University of Almería.