Title : Effects of Trichoderma and Bacillus biofertilizers on physiology, yield, and oil quality of sesame under different water regimes
Abstract:
Water scarcity is a major constraint to crop productivity in semi-arid regions, where improving drought adaptation mechanisms is critical for sustainable agriculture. This study evaluated the combined role of supplementary irrigation and biofertilizers in enhancing drought tolerance, physiological performance, and yield of sesame (Sesamum indicum L.) under field conditions in Jordan. Field experiments were conducted during the 2025 growing season at two contrasting semi-arid locations using a split-plot design. Five water regimes based on field capacity (rainfed, 25%, 50%, 75%, and 100%) were assigned as main plots, while four biofertilizer treatments (control, Bacillus subtilis, Trichoderma harzianum, and their combined application) were arranged as subplots. Plant growth traits, physiological indicators, yield components, and oil productivity were assessed. Results showed that increasing water availability significantly improved plant water status, photosynthetic activity, growth, and yield, with optimal performance achieved at 75% field capacity. Applying full irrigation did not result in further yield gains. The combined biofertilizer treatment consistently enhanced plant height, chlorophyll content, gas exchange parameters, and relative water content under water-limited conditions. These physiological improvements translated into higher grain and oil yields compared to single inoculations or untreated controls. Notably, oil content and quality were not adversely affected by either irrigation level or biofertilizer application. The study demonstrates that integrating moderate supplementary irrigation with combined microbial biofertilizers is an effective and water-efficient strategy to improve drought adaptation, productivity, and sustainability of sesame cultivation in semi-arid environments. This approach offers practical implications for climate-resilient crop management in water-limited regions.
