Influence of the phenological stages on ionic alterations in aubergine plants (eggplant)

Abstract

Aubergine eggplant plants (Solanum melongena L.) were grown under greenhouse conditions with nitrogen and phosphorus fertilization individually, or both, and with a large amount of organic matter and CaSO 4 in the soil superficie. The irrigation water was strongly brackish. In the plants, nitrate and phosphate showed an obvious mobility, whereas chloride and sulfate were relatively immobile. Cations in the form of potassium and ammonium were highly mobile, during the growth cycle, whereas the other cations tested were immobile. Translocation of anions was weak with little change in concentration throughout the growth cycle, whereas cations showed marked variations in different stages due to the influence of NH 4 + and K + mobilization. The accumulation of cations was offset by hydrogen extrusion to maintain foliar pH within physiological limits. Sharp changes in pH were buffered by the effect of citric acid as an organic anion, which absorbed the excess positive charge. Alterations in cations increased the formation of organic acids, a process clearly dependent on the stage of the growth cycle. The finding of this study is that behavior of ion balances remained constant regardless of the dose of fertilizer applied, but changed in response to the stage of the growth cycle. 1353

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

“…Leaf samples were taken only from plants with fully expanded leaves of the same size (> 25 cm). Leaves were picked about one-third of the plant height from the plant apex during flowering (95 days after transplanting until 170 days) every 2 weeks (Lo ´pez-Cantarero et al, 1995). Leaves were rinsed three times in distilled water after being disinfected with nonionic detergent at 1% (Wolf, 1982), then blotted on filter paper.…”

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

“…Leaf samples were taken only from plants with fully expanded leaves of the same size (>25 cm). Leaves were removed from a zone at about two-thirds of the total height of the plant, during flowering (95 days after transplanting until 170 days) every 2 weeks (Lo ´pez-Cantarero et al, 1995). Leaves were rinsed three times in distilled water after disinfection with nonionic detergent at 1% (Decon 90, Merck) (Wolf, 1982) and then blotted on filter paper.…”