Potassium limitation was reflected by
fruit analysis; aquaponic tomatoes contained
22.0 gKkg1 dry matter versus 40.8 gKkg1
dry matter in hydroponic.
In an experiment in 2003, different tomato
varieties were tested in the same setup [14].
All varieties yielded more fruit in aquaponic,
which could be partly explained by the higher
water temperature in aquaponic and thus faster
initial growth of the plants, leading to earlier ripening
(Fig. 4). Tomato yields were generally low
because of temperature stress caused by very hot
conditions in summer 2003. Sensory assessment
of ripe fruits of the variety «Grappella» revealed
that 15% of people preferred the taste of tomato
grown in aquaponic, 21% the hydroponic type,
47% fruits cultivated in soil and 17% could not
detect any differences (n = 19).