The influence of NaCl salinity on growth, yield and fruit quality of strawberry cvs. ‘Elsanta’ and ‘Korona’

Abstract

In a 2-year field study, strawberry cvs. ‘Elsanta’ and ‘Korona’ were exposed to three different levels of NaCl salinity supplied as aqueous solutions characterised by electrical conductivities of 0.3 dS/m, 2.6 dS/m, and 5.1 dS/m. Salinity in the rhizosphere reduced plant growth by up to 44% in ‘Korona’ and 90% in ‘Elsanta’. A rather distinct cultivar difference represented the reduction in leaf area per plant of 85% in the second year of experiment in ‘Elsanta’ compared to 29% in ‘Korona’. Strawberry can be regarded as a Na + excluder, because Na + content of both strawberry cultivars remained below 3 mg g −1 dry mass at all salinity levels. Cl − content increased considerably, up to 70 mg g −1 dry mass in ‘Korona’ and 80 mg g −1 dry mass in ‘Elsanta’ plants. ‘Korona’ retained most of its Cl − in roots and crowns, whereas in ‘Elsanta’ the maximum was detected in petioles. ‘Korona’ was able to accumulate up to 33% higher Cl − content in the roots than ‘Elsanta’. Macronutrient deficiency due to NaCl salinity was not observed and in comparison to ‘Elsanta’, higher Cl − content in roots of ‘Korona’ did not coincide with an impairment of macronutrient uptake. Salinity stress reduced fruit yield by up to 27% in ‘Korona’ and 64% in ‘Elsanta’. Fruit quality, characterised as taste, aroma, and texture by a consumer-type panel, decreased by more than 24% in ‘Elsanta’, but in ‘Korona’ differences were insignificant. Total soluble solids (Brix) and the ratio Brix/TA (TA, titratable acid) decreased significantly by about 20% in ‘Korona’ and 35% in ‘Elsanta’. To summarise, the ability of ‘Korona’ to retain Cl − in the root system more effectively than ‘Elsanta’ resulted not only in a 41% lower leaf Cl − content at the highest salinity level and a better growth under NaCl stress, but also in a relatively higher fruit yield and fruit quality.