Impact of Marine Fish Amino Acid on Yield Parameters and Preventive Antioxidant in Okra

Abstract

A field experiment was carried out to evaluate the effects of foliar-applied marine fish amino acids (MFA) on the growth, yield, yield components, and preventive antioxidant capacity of okra, as well as the interaction between okra varieties and MFA concentrations. The study used a split-plot design with four replications. Three okra varieties — RED FINGER, KN–OYV–02, and LUCKY FILE 473 — were assigned to main plots. Five concentrations were tested in the subplots (0.00, 1.50, 3.00, 4.50, and 6.00 ml/l). Yield per plant — a key indicator for growers — did not differ significantly among the three varieties but responded to MFA levels-plants treated with 3.00, 4.50, or 6.00 ml/l. MFA showed no significant differences among these higher concentrations; however, all produced higher yields than the untreated control and the 1.50 ml/l treatment. The greatest yield (1,271.49 g/plant) was obtained at 3.00 ml/l, followed by 4.50 ml/l (1,251.22 g/plant) and 6.00 ml/l (1,215.51 g/plant). Reducing sugar content did not vary significantly among the okra varieties but was influenced by MFA levels. LUCKY FILE 473 recorded the highest reducing sugar (~1.77 mg/ml). The concentrations 3.00, 4.50, and 6.00 ml/l yielded the highest reducing sugar levels (1.89, 1.84, and 1.77 mg/ml, respectively), with no significant difference among them, while the control plants had the lowest value (1.53 mg/ml). Among pigment traits, RED FINGER exhibited the lowest chlorophyll a, chlorophyll b, and total chlorophyll contents (2.96, 1.51, and 4.47 mg/g FW, respectively) but had the highest carotenoid concentration (0.50 µg/g FW).