Effect of Grape Rootstocks on Chloride Accumulation in Leaves1

Abstract

The effect of 5 rootstocks on chloride accumulation in ‘Cardinal’ and ‘Thompson Seedless’ scions was studied for 3 years in large sand cultures containing 12.5, 25, and 50 meq Cl - /liter of culture solution. Rootstock effects were unprecedentedly large. Scions on ‘Thompson Seedless’, ‘Dog Ridge’, 1613-3, and ‘Salt Creek’ roots consistently accumulated only one-half, one-third, one-tenth, and one-sixteenth as much chloride, respectively, on a leaf dry-weight basis as did scions on ‘Cardinal’ roots. Rootstock effects on chloride in canes and roots were similar to those in leaves, although differences were not as great. Leaves of ‘Cardinal’ scions accumulated more chloride than those of ‘Thompson Seedless’ on the 2 lower chloride treatments, apparently because of differential distribution of chloride between leaves and stems. Chloride accumulation tended to be proportional to substrate chloride concentrations for all rootstocks, and increases in chloride accumulation associated with advancing season and vine age also tended to be proportional. Because of extremely low chloride accumulation by vines on 1613-3 and ‘Salt Creek’ roots, the salt tolerance of grapevines on these roots would probably be limited by osmotic effects long before chloride accumulation reached toxic levels. Rootstock and chloride-treatment levels caused no other important nutritional or toxic effects.