Secondly, and more negatively, chloride interfere with photosynthesis. It slows the food manufacturing process in the chloroplast of the leaves, thus reducing the overall health of the vine. Chloride can be slowing down the productivity of a vine for years without obvious symptoms. In extremely toxic conditions, chloride accumulates at the leaf margins and kills the tissue via dehydration. Once the vine is showing chloride leaf burn, the vines and soil are in very serious condition.
Sodium is much more difficult to understand.
It has been reported that sodium has limited negative effect on the leaves, however, this is unknown. The effect of sodium on the soil is well documented and it is very negative. Sodium can kill the soil. Soil or water with a SAR above 4 is trouble. If the SAR is above 7, grapes should not be grown.