Abstract: Variation in soil Nitrogen (N) content affect growth and development of egg plant (Solanum melongena L.) and may lead to changes in crop physiological conditions at flowering and the physio-chemical qualities of fruit and seeds produced. Two experiments with a `long purple` variety of eggplant were carried out under field conditions to establish the relationship between N availability and fruit qualitiesand between the fruit size and q ualities of the seeds produced. The treatments consisted of four N levels (0, 40, 60 and 80 kg N ha-1) combined factorially with three fruit sizes: small (0-2.5 cm in diameter, S1), medium (2.6-5cm, S2) and big (>5cm, S3). Fresh fruit physio-chemical qualities such as fruit weight and diameter, per fruit number of seeds and seed weight, fruit pH, % juice, Crude Protein (CP), total solid, Fe and ascorbic acid contents were assessed. Data collected were statistically analyzed for determination of treatment effects. Nitrogen deficiencies reduced both physical and chemical properties of egg plant fruit. For most of the parameters assessed 80 kg N ha-1 treatment proved to be the best. However, crop performance under 60 kg N ha-1 fertilizer regime were, in most cases, were not statistically siginificant when compared to application 80 kg N ha-1. The biggest fruit (S3) consistently had the best physio-chemical qualities irrespective of N level. The exceptions to this are CP where there was no responseand seed weight/fruit and Fe content where S2 and S3 fruit sizes gave similar results. It was concluded that for production of high quality fruits and seeds in eggplant, application of 60 kg N ha-1 in combination with selection of big fruit (= 5cm in diameter) seems to be the best agronomic practices.
W.B. Akanbi , A.O. Togun , O.A. Olaniran , J.O. Akinfasoye and F.M. Tairu , 2007. Physico-Chemical Properties of Egg Plant (Solanum melongena L.) Fruit in Response to Nitrogen Fertilizer and Fruit Size. Agricultural Journal, 2: 140-148.