Nitrogen metabolism and yield response to increases in nitrogen-phosphorus fertilization: Improvement in greenhouse cultivation of eggplant (Solanum melongena cv. Bonica)

Abstract

The effect that application of nitrogen-phosphorus (NP) rates exerts on some parameters of nitrogen metabolism and on yield in aubergine plants (eggplant, Solanum melongena 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 (N-1: 15 g m(-2), N-2: 22.5 g m,(-2) and N-3: 30 g m(-2)) together with two rates of P in the form of H3PO4 (P-1: 24 g m(-2) and P-2: 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 NO3-assimilation as well as total and commercial yield. Use of the P-2 rate favored all of these processes in comparison with the results obtained with the P-1 rate, in addition to notably reducing the foliar levels of NO3-and noncommercial yield.