Effecten van verhoging van Na in de voedingsoplossing bij Phalaenopsis: Bepaling van de schadedrempel voor Na in het wortelmilieu van phalaenopsis met recirculatie

A full cultivation trial with Phalaenopsis, from potted plug plant to flowering, was conducted with sodium concentrations ranging from 0 to 10 mmol/l, with a series with equal total EC and a series with increasing EC; the cultivars Leeds and Morelia were used. Growth and production was significantly lower at 10 mmol/l and an EC of 1.5 mS/cm, caused by low K. At the same Na concentration and a constant K supply, growth and flowering were not affected. The higher EC values gave slightly more flower branches and had slightly smaller flowers. In a post-harvest test, the ornamental value decreased sharply at the highest Na gift and the plants with high sodium with an increasing EC also had a lower ornamental value due to more bud-abortion and especially leaf yellowing. Na uptake was linear with the supply and appears to be very high in phalaenopsis. Most of the Na is stored in the old leaves. The uptake concentration is very high at 10 – 12% of the prevailing concentration in the root environment compared to other horticultural crops. The conclusion is that the maximum Na concentration can be increased to 6 mmol/l at an EC of 1.5 dS/m.