Effects of Production Method (Flooded Media Bed or Floating Rafts) on Growth, Production, and Mineral Composition of Okra (Abelmoschus esculentus) Grown in a Coupled Aquaponic System with Nile Tilapia (Oreochromis niloticus)

As the global population continues to rise, sustainable agricultural systems such as aquaponics have gained attention for their potential to maximize food production while minimizing resource use. This study evaluated the growth performance, yield, and mineral composition of okra (Abelmoschus esculentus) grown in a coupled aquaponic system with Nile tilapia (Oreochromis niloticus), comparing two production methods: floating raft and flooded media bed. Okra was cultivated at two planting densities (32 and 48 plants/m2) over a 12-week period, and multiple plant growth parameters and tissue mineral compositions were assessed at harvest. Results showed that plant production method significantly (p < 0.05) influenced okra growth and yield, while planting density had limited impact. Okra grown in media beds exhibited greater (p < 0.05) stem length, stem and root weights, number of leaves, and okra (fruit) production compared to those grown on floating rafts. Although root length was longer (p < 0.05) in raft-grown plants, root biomass was notably higher (p < 0.05) in plants grown in media beds. Mineral composition of plant tissues also varied with production method and density. Media-grown okra generally had higher (p < 0.05) concentrations of calcium, phosphorus, and copper in leaves and stems, whereas raft-grown plants showed elevated levels of sodium and zinc in several tissues. Plant density affected a few specific mineral concentrations, particularly in roots and fruit, though effects were inconsistent. While fish growth was not high, possibly due to some water quality parameters (such as alkalinity and hardness) not being optimal, plant performance in media beds without supplemental nutrient inputs highlights the viability of fired clay media in aquaponic okra production. These findings suggest that media beds offer agronomic advantages over floating rafts for okra cultivation in aquaponic systems, with implications for optimizing nutrient delivery and plant health in sustainable food production systems.