Optimizing Planting Materials and Hormonal Treatments to Enhance Root Morphology and Physiological Traits in Wonder Elephant Grass for Sustainable Fodder, Energy, and Carbon Yield

The shortage of high-quality green fodder and biomass for energy production could be minimized by optimizing propagation techniques for high-biomass crops such as elephant grass. A four-year study (2019–2021) under field and controlled conditions under a semi-arid climate evaluated the suitability of stem cuttings for planting, and standardization of growth hormone treatment for improved rooting, followed by optimization of planting and cutting intervals. Results revealed that top-portion stem cuttings achieved 98.1% rooting, greater seedling vigor, and improved yield due to enhanced root length, stomatal conductance (122.3 mmol/m2/s), total soluble sugars, and soluble protein content. Treating stem cuttings with 100 ppm of indole-3-butyric acid (IBA) for 15 minutes significantly enhanced rooting (∼82%), root volume, transpiration rate (2.9 m mol/m2s), and net CO2 assimilation rate (11.8 μmol/m2/s), even under delayed planting conditions. Combining top cuttings with IBA treatment resulted in the highest green fodder yield (232.6 t/ha/year), crude protein yield (20.7 t/ha/year), and energy yield (972,695 MJ/ha/year), owing to improved rooting and physiological performance. Furthermore, this combination enhanced the net return by 5–10% over middle- and bottom-portion cuttings. Overall, these nursery management techniques improve elephant grass establishment, making it a sustainable source of green fodder, bioenergy, and carbon sequestration for tropical and subtropical regions over conventional practices.