Reciprocal grafts of burley (cv. KY 14) and flue-cured (cv Speight G28) tobacco (Nicotiana tabacum L.) shoots were used to ascertain the effect of the root system genotype on dry weight, total N, and nitrate N accumulation by shoots. Plants were grown at a high soil N fertility level comparable to a burley tobacco management system. Plants were harvested at topping and at 21 days after topping, and separated into lamina, midveins and stalks. Dry weight and total N accumulation was greater for shoots of burley relative to flue-cured tobacco. Concentration and content of nitrate N tended to be higher for burley than for flue-cured shoots. These data suggested that at the high N fertility level used, flue-cured leaves were saturated at a lower concentration level in their capacity to reduce transported nitrate N. All observed differences in dry weight and N constituents between total shoots and shoot parts were not affected by the genotype of the root system Thus, it was concluded that the root system does not limit N accumulation by the shoots of burley and flue-cured tobacco grown at a high N fertility level.

(Full article published with kind permission from "Tobacco International")