Ann. Tabac, 1987, Sect. 2-21, p. 81-90., ISSN.0399-0354

Utilization of nitrite nitrogen as related to nitrate content of leaves in three varieties of Nicotiana tabacum L

TANCOGNE J.; VIDAL B.
SEITA, Institut du Tabac, Bergerac, France
Two in pot culture experiments were carried out, one with a hydroponic system, the other on a sandy soil. In each experiment, three tobacco varieties were compared : burley BB 16, Virgin D and the brown air-cured tobacco PB D6, with the same amount of nitrate nitrogen fertilizer. At harvesting time, BB 16 always had the most important nitrogen content; it did not absorb more nitrogen than the other varieties but produced much less biomass, which lead to a smaller autodilution for this element. Comparing the non reduced N-total N ratio in tissues at the end of the growing period, it may be stated that PB D6 is the best variety from the point of view of nitrate assimilation. These two experiments also showed that nitrate accumulated in the lower leaves, at the beginning of growth was not translocated into the upper leaves even if these showed a shortage of nitrogen during their development.