Nitrogen Metabolism and Yield Response to Increases in Nitrogen-Phosphorus Fertilization: Improvement in Greenhouse Cultivation of Eggplant (Solanum melongena Cv. Bonica)

The effect that application of nitrogen-phosphorus (NP) rates exerts on some parameters of nitrogen metabolism and on yield in aubergine plants (eggplant, Solanummelongena cv. Bonica) was studied. All plants were grown under controlled conditions in an experimental greenhouse. The treatments consisted of the combination of three rates of N in the form of KNO3 (N1: 15 g m-2, N2: 22.5 g m,-2 and N3: 30 g m-2) together with two rates of P in the form of H3PO4 (P1: 24 g m-2 and P2: 36 g m-2), for a total of six treatments. Results indicate that regardless of the P rate applied, an increase in the N fertilizer increased NO3assimilation as well as total and commercial yield. Use of the P2 rate favored all of these processes in comparison with the results obtained with the P1 rate, in addition to notably reducing the foliar levels of NO3and noncommercial yield.