Organic amendments improve salinity-induced osmotic and oxidative stress tolerance in Okra (Abelmoschus esculentus (L.)Moench)

anglais. Aims Salinity adversely afects okra [Abelmoschus esculentus (L.) Moench] plants by inducing osmotic and oxidative stresses. This study was designed to enhance salinity-induced osmotic and oxidative stress tolerance in okra plants by applying organic amendments. Methods The efects of diferent organic amendments (municipal solid waste compost, farmyard manure (FYM) and press mud) on osmotic potential, water use efciency, activities of antioxidant enzymes, total soluble sugar, total soluble proline, total soluble protein and malondialdehyde (MDA) contents of okra plants grown under saline condi‑ tions (50 mM sodium chloride) were evaluated in a pot experiment. The organic amendments were applied each at the rate of 5% and 10% per pot or in various combinations (compost+FYM, FYM+press mud and compost+press mud each at the rate of 2.5% and 5% per pot). Results As compared to control, high total soluble sugar (60.41), total soluble proline (33.88%) and MDA (51%) con‑ tents and increased activities of antioxidant enzymes [superoxide dismutase (83.54%), catalase (78.61%), peroxidase (53.57%] in salinity-stressed okra plants, were indicative of oxidative stress. Salinity signifcantly reduced the osmotic potential (41.78%) and water use efciency (4.75%) of okra plants compared to control. Under saline conditions, 5% (farmyard manure+press mud) was the most efective treatment, which signifcantly improved osmotic poten‑ tial (27.05%), total soluble sugar (4.20%), total soluble protein (73.62%) and total soluble proline (23.20%) contents and superoxide dismutase activity (32.41%), compared to saline soil. Application of 2.5% (FYM+press mud), 5% press mud, and 10% compost signifcantly reduced MDA content (27%) and improved activities of catalase (38.64%) and peroxidase (48.29%), respectively, compared to saline soil, thus facilitated to alleviate oxidative stress in okra plants. Conclusions Using organic amendments (municipal solid waste compost, farmyard manure and press mud) was a cost-efective approach to improve salinity-induced osmotic and oxidative stress tolerance in okra plants.

anglais. Okra, Organic amendments, Salinity stress, Compost, Farmyard manure, Press mud

140

1-15

1