Optimum levels in organs of N-P-K fertilized eggplants (Solanum melongena L.) I. Nitrogen parameters

Egglants (Solanum melongena L. cv. Bonica) were grown under controlled gree nhouse conditions. The treatments and dosages were: NH4NO3, N-1 (4 g/m(2)), N-2 (8 g/m(2)), N-3 (16 g/m(2)); PO4H3, P-1 (13 g/m(2)), P-2 (26 g/m(2)), P-3 (52 g/m(2)); K2SO4, K1 (5 g/m(2)), K-2 (10 g/m(2)), K-3 (20 g/m(2)), K- 4 (30 g/m(2)); and T-0 only organic matter (manure). In the present study w e have determined NO3-, NH4+, Mineral N, Organic N, Assimilated N and Total N on dry matter and foliar NRA on fresh matter. The values for N fractions in leaf and fruit appear to indicate an increase in the transport from lea f to fruit, so that leaf figures lay mostly in the suboptimum interval, whi le fruit Figures reached the high interval. This alteration in transport ma y be due to excessive fertilization, especially in N form. Considering the preferential accumulation of N in the fruit (which is harmful to both quali ty and quantity of harvest) and the extra costs of NPK fertilization, it is obvious that even at the lowest rates, fertilization is totally out of the question for this crop under the conditions used in the present trial.