Tomato and tilapia yield, quality and safety in an intensive aquaponic system

ABSTRACT In aquaponics, a limitation in productive performance is the concentration of nutrients for plant development. So, the intensity of fish in the culture could be an internal variant that favors the presence of nutrients, thus avoiding their external supply. Therefore, the aim was to determine the effect of intensive fish density during its three biological stages (fingerling, juvenile, and adult) on the yield, quality, and safety of tomato (Solanum lycopersicum) and tilapia (Oreochromis niloticus) in an aquaponic system. The study was conducted using a randomized block design, having as an experimental unit an intensive aquaponic system and as a control, an aquaculture module and a hydroponic module, each with three replications. The response variables for plant yield were dry weight, relative growth rate, crop growth rate, survival rate, and production per plant, and for fish, there were growth rate, feed conversion factor, protein efficiency ratio, and survival rate. For fruit quality, the variables were pH, total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, and lycopene content; for fillet quality, the following were considered: percentage of protein, lipids, ash, and nitrogen-free extract. Finally, in the safety evaluation of both products, the variables were the presence of total coliforms, Salmonella, and Escherichia coli. Intensive fish density (40 kg/m³) significantly improves tilapia biomass and fillet quality, while tomato yield remains comparable to that of hydroponics, with some quality variables even higher, without showing significant differences in the microbiological safety of the fillet or the fruit.