Addition of nitrate significantly increased nitrogenous fractions (NO^-₃, T.N.,T., S.N)*, fresh and dry weights of roots and shoots in both plant species.  Carbohydrates (T.S.,T.,S.S)*, acetylene reduction activity (A.R.A)* and nodule fresh weights were significantly decreased as compared with untreated nodulated plants.  The depressive effect of nitrate on acetylene reduction activity is discussed in relation to hypotheses explaining photosynthate demand for nitrate assimilation in the nodules (assimilate deprivation), or nitrite poisoning.  Present data are in favour of the assimilate deprivation hypothesis.