Potted two-year-old Fine lemon plants (Citrus limon (L.) Burm. hi.) gr
afted on two different rootstocks: sour orange (C. altrantium) (SO), a
nd C. macrophylla (CM) were submitted to two different treatments: non
-flooded (control) and flooded for 8 days, under field conditions. Lem
on/CM plants had lower plant plus soil resistance to water how (R((p+s
))) values for both treatments. The decrease in leaf water potential (
Psi(l)) and leaf turgor potential (Psi(p)) values, observed in the las
t part of the flooding period, in both hooded scion/rootstock combinat
ions, can be related to the increase in the resistance to water how. T
he maintenance in Psi(l) and Psi(p) values in hooded plants at values
similar to those of the control plants, at the beginning of the hoodin
g period and during the recovery period, can be ascribed to the stomat
al control observed (decrease in leaf conductance (g(l)) values). The
later g(l) recovery in lemon/CM than in lemon/SO flooded plants, could
explain the lower vegetative growth of lemon/CM plants by flooding ef
fect. The observed g(l) response to soil flooding suggested that porom
etry is a reliable indicator of the altered behaviour caused by floodi
ng in lemon plant.