Impact of NaCl^– salinity on growth, yield and K⁺ uptake of tomato crops grown in a split-root system using Rb⁺ as tracer

Aiming to study growth performance and relative potassium (K⁺) uptake of tomato plants exposed to NaCl^– salinity in half of their root system.
Tomato plants were grown in a recirculating nutrient solution (NS) at the experimental facilities of the Laboratory of Agricultural Structures, at the Agricultural University of Athens.
Two different nutrient solutions (NS) were supplied to the plants; a standard NS, and a NS containing 10 mM of NaCl.
Tomato plants were grown either in gullies which were supplied with the standard NS, or in gullies which were supplied which the NS containing NaCl.
A third treatment was also applied using a dual-channel system that allowed root splicing into standard NS compartments and into a NaCl-salinized compartment. (Rb⁺) was used as tracer element in order to study K⁺ absorption capacities of tomato (leaves) under unequal distribution of NaCl-induced salinity in the root zone.
The results of this study revealed that the exposure of the entire root system of tomato to salinity significantly reduced leaf area and total yield in comparison with the standard NS, for both treatments (the salinity treatments and the partial exposure to salinity). In the partial exposure treatment, the non-salinized part of the root system accounted for 55% of the total root dry weight.
The use of Rb⁺ as tracer revealed that under unequal salinity, the uptake of K⁺ was unequal in the two root parts and not proportionally to the root mass.
In conclusion, most of K⁺ was absorbed from the non-salinized compartment.

International Symposium on Models for Plant Growth, Environments, Farm Management in Orchards and Protected Cultivation – HorchiModel2023

I. Lycoskoufis, G. Mavrogianopoulos

salinity, potassium uptake, hydroponics, split root, electrical conductivity

https://doi.org/10.17660/ActaHortic.2025.1425.33