Enhancing Drought Resilience in Okra Through the Application of Indole Acetic Acid (IAA) Producing Rhizobacteria in Soil

Drought is a significant contributor, lowering crop production in arid to semi-arid areas. Rhizosphere bacteria play a crucial role in promoting plant growth and providing eco-friendly and efficient ways to ameliorate drought. Bacterial exopolysaccharides (EPS) and indole-3-acetic acid (IAA) are key in enhancing drought tolerance by soil aggregation, improving water retention, root proliferation, and development in soil. Okra, a perishable vegetable, is highly susceptible to water shortages. This study aimed to improve drought tolerance in okra under water deficit conditions through the application of IAA-producing rhizobacteria. Two jar experiments were conducted to test the potential of ten rhizobacterial strains under different polyethylene glycol (PEG-6000) levels (0, 2, 4, 6, and 8%) against osmotic stress. Results showed a significant increase in shoot and root length (25 and 26%, respectively), root colonization (26%), germination (26%), root volume (25%), and total root length (25%) by bacteria inoculation as compared to control. Furthermore, consortium application demonstrated higher fresh and dry weights for shoots and roots (19, 23, 22, and 25%, respectively), as well as increased root diameters and surface area (24 and 23%, respectively) under water-deficient conditions compared to sole inoculation. In conclusion, microbial consortia were more effective in ameliorating drought in okra and need further testing in natural conditions for biofertilizer development.