As expected, control plants grown with Fe (Fe10) in the nutrient
solution did not develop symptoms throughout the entire experiment
and Chlorophyll values were always above 720 mmol m2
.
After 35 days plants under Fe0 conditions developed chlorotic
strawberry leaves showing SPAD values between 0 and 21
(Chl < 376 mmol m2
). At this stage, the chlorotic plants were
divided into two groups: (i) one set remained without Fe (Fe0), and
(ii) for the other set (FeR) the nutrient solution was supplemented
with 10 mM of Fe in order to evaluate the effects of recovery from
the stress. Plants growing under the three treatment conditions
were maintained for additional two weeks: Fe0 (always grown
without Fe; n > 36); Fe10 (control plants, always grown with Fe;
n > 42), and FeR (chlorotic plants treated by adding Fe to nutrient
solution; n > 20). The containers used in the experiment were
placed in a randomized design, each one with six plants.