Phosphorus 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 phosphorus metabolism in 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 (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. The results obtained show a positive effect of NP fertilization on the nutritional status of P in the plants, clearly reflected in the response of bioindicators of the P (acid phosphatase activity and carbohydrates). The plants treated with N3P2 registered greater integration or assimilation of inorganic P to organic P, a fact that may be related to the maximum total and commercial yield in these plants and minimum noncommercial yield.