The effect of nitrate and urea forms of nitrogen on the metabolism of tomato plants grown by the nutrient film technique
S. Rożek*, W. Sady**, J. Myczkowski*
**Department of Plant Physiology
**Institute of Vegetables and Ornamental Plants
**Faculty of Horticulture, Agricultural University
**29 Listopada 54, 31-425 Kraków, Poland
The effect of the nitrate and urea forms of nitrogen and of a mixture of
these two forms on the activity of nitrate reductase, as well as on the
content on nitrates, nitrites, and saccharides and K, Ca, and Mg, were
investigated in the leaves of a greenhouse tomato Ostona F1
cultivar grown by the nutrient film technique.
In separate nutrients a rapid change of urea into the nitrate form was observed, which may be confirmed
by a high level of nitrates in the leaves of plants grown even on the
nutrient containing nitrogen only in the urea form. The highest activity
of nitrate reductase and also the content of nitrates were determined in
the leaves of plants grown on the nutrient containing 75% nitrogen in the
amide form and 25% of that in the nitrate one. The nutrients used in the
experiment, differentiated in respect of the fraction of particular
nitrogen forms, also affected the content of nitrites, saccharides, K, Ca, and Mg in the tomato leaves.
Rożek S., Sady W., Myczkowski J., 1990. The effect of nitrate and urea form of
nitrogen on the metabolism of tomato plants grown by the nutrient film technique. Folia Horticulturae II/2: 13-27.