the effect of root partial salinization on the photosynthesis rate and nutrient concentration in strawberry

salinity affects the yield and quality of fruits crops as result of modifying water and nutrient uptake. in split root system, it should be possible to reduce the deleterious effect of salinity on the plant growth. therefore, an experiment was conducted on strawberry with different concentration of nacl (0, 30, 60 and 90 mm) in a completely randomized blocks design in studding hydroponic greenhouse. the roots were divided into two portions and either even or uneven salinity was applied to the root portions. the treatments consist of 0:0, 0:30, 0:60, 0:90, 30:30, 60:60 and 90:90 with three replications. in general, the increased salinity reduced photosynthesis rate but in uneven salinity the photosynthesis rate was increased. proline concentration was reduced in 0:0 treatments but increased in 0:30 and 30:30 treatments. ca, n, p and k concentrations were reduced by increasing salinity, but were increase in uneven salinity. the highest concentrations of cl and na were observed in 60:60 and 90:90 salinity treatments. na and cl concentrations were reduced in uneven salinity in the root zone so that in 0:30 treatments, the concentration of na were 20% lower than that in 30:30 treatments. based on the results of this study the application of uneven salinity in a concentration of 30 mm could be recommended for growing strawberry in salinity stress conditions.