Tomaat telen met verhoogd Natrium (proef 2019): Hoe om te gaan met oplopend Na in het wortelmilieu?

The effect of sodium accumulation on tomato growth and production was tested in a trial with a crop in stone wool with full recirculation of drain water. Treatments varied from 10 to 25 mmol/l sodium, with two periods of gradual increase, in an 11-month crop. No significant differences were found on yield or quality (shelf life or taste). Blossom End Rot (BER) did not occur. On the basis of the results of this trial, the maximum acceptable level for Na can be increased from 8 to 15 mmol/l. The uptake concentration was linear with the Na concentration in the root environment and is at a reasonable level with approx. 1 mmol/l at 15 mmol/l. From these results it is to be expected that when using rainwater only or water with comparable quality a fully closed cultivation is possible for tomato. Even so this is possible at Na concentrations of less than 1 mmol/l in the water applied.