I. Lopezcantarero et al., INFLUENCE OF THE PHENOLOGICAL STAGES ON IONIC ALTERATIONS IN AUBERGINE PLANTS (EGGPLANT), Journal of plant nutrition, 18(7), 1995, pp. 1353-1370
Aubergine eggplant plants (Solanum melongena L.) were grown under gree
nhouse conditions with nitrogen and phosphorus fertilization individua
lly, or both, and with a large amount of organic matter and CaSO4 in t
he soil superficie. The irrigation water was strongly brackish. In the
plants, nitrate and phosphate showed an obvious mobility, whereas chl
oride and sulfate were relatively immobile. Cations in the form of pot
assium and ammonium were highly mobile, during the growth cycle, where
as 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 t
he influence of NH4+ and K+ mobilization. The accumulation of cations
was offset by hydrogen extrusion to maintain foliar pH within physiolo
gical limits. Sharp changes in pH were buffered by the effect of citri
c acid as an organic anion, which absorbed the excess positive charge.
Alterations in cations increased the formation of organic acids, a pr
ocess clearly dependent on the stage of the growth cycle. The finding
of this study is that behavior of ion balances remained constant regar
dless of the dose of fertilizer applied, but changed in response to th
e stage of the growth cycle.