Combined foliar application effect of iron and potassium on growth of okra and striped catfish using media bed based aquaponics

An experiment for 90 days was carried out to evaluate the combined effect of iron and potassium by foliar method on the growth of okra, Abelmoschus esculentus and striped catfish, Pangasianodon hypophthalmus using a media bed in aquaponics. The different iron dosages i.e. T1 (0.50 g/L), T2 (0.75 g/L), T3 (1.00 g/L), T4 (1.25 g/ L), along with potassium at 5 g/L were applied in all the treatments twice a month. All four treatments and a control were in triplicate. No significant (P > 0.05) difference was noticed in the quality of water in all the treatments and control. The okra showed significantly better growth in the treatments than the control, especially in T3 and T4. The yield of okra found was to be significantly (P < 0.05) higher in T4 (36.67 +/- 0.81 g/plant) as compared to control (17.16 +/- 0.47 g/plant). The mineral composition and proximate analysis of the okra pod revealed considerably higher crude protein, potassium, and iron content in T3 and T4, and leaf potassium and iron content were observed to be higher in T4 as compared to other treatments. The growth performances, haematological and antioxidant enzymes analysis of fish, exhibited an insignificant variation (P > 0.05) among the treatments and control. From the findings of the present experiment, it can be concluded that the foliar application of iron dosage of 1.00 g/L in combination with 5 g/L potassium can improve the growth and yield of okra without any adverse effect on fish growth in aquaponics.