INTERACTIVE EFFECTS BETWEEN BIOFERTILIZER AND ANTIOXIDANT ON SALINITY MITIGATION AND NUTRITION AND YIELD OF OKRA PLANTS (Abelmoschus esculentus L.)

A greenhouse pot experiment was conducted to explore how to alleviate the deleterious effects of saline-irrigation water on the growth and the yield of okra plants, as well as to limit the physiological and biochemical changes induced through salinity stress, bio-fertilization and antioxidant application. The soil was irrigated with saline water levels: tap water (0.47), 2, and 4 dSm^-1. The biofertilizer Nitroben treatments were applied as an inoculum to okra seeds before cultivation. The ascorbic acid levels (100 and 200 mg.l^-1) were added as a foliar spray. The results revealed that salt stress caused significant reductions in growth variables including plant height and pods dry and fresh weights in comparison with the negative and positive controls. The combined treatments of biofertilizer and ascorbic acid significantly ameliorate the negative effects of salinity levels on okra growth parameters. The combined treatments of biofertilizer and ascorbic acid significantly increased total chlorophyll contents in leaves of okra plants. Also, the combined treatments of biofertilizer and ascorbic acid significantly increased ascorbic acid contents in okra plants compared with the contents of salinity affected plants. The increase of salinity levels significantly increased proline content in okra plants. The combined treatments of biofertilizer and ascorbic acid levels significantly ameliorate the negative effects of salinity levels on micro and macro-nutrients concentrations in okra plants. It can be concluded that T11 (Soil + S2 (2.00 dSm^-1) + ascorbic acid (100 mg.l^-1) + biofertilizer) treatment was the best for the growth performance of okra plant.