Enhancing Germination and Early Growth of Millets (Sorghum bicolor L. and Pennisetum glaucum L.) Using Plasma-Activated Water
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Abstract
The application of non-thermal plasma in agriculture has emerged as an eco-friendly technology to enhance seed vigor and crop productivity. In this study, the effects of plasma activated water (PAW) generated through atmospheric pressure gliding arc discharge (GAD) plasma were evaluated on two staple millets, Jowar (Sorghum bicolor L.) and Bajra (Pennisetum glaucum L.). PAW treatments of varying activation times (5, 10, 15, and 20 min) were tested against a control (untreated water). Physicochemical analysis revealed a decrease in pH (from ~5.8 to ~3.7), along with significant increases in electrical conductivity, oxidation - reduction potential, and nitrate concentration (up to ~240 mg L⁻¹) with increasing activation time. Biological assays demonstrated that PAW significantly enhanced seed performance and early growth in both crops. For Sorghum bicolor L., 10 min PAW treatment was identified as the optimum, resulting in an increase in germination from 92% (control) to 98%, a reduction in mean germination time, and ~25–30% improvement in shoot length. For Pennisetum glaucum L., 15 min PAW treatment was optimal, yielding germination enhancement from 89% to 97%, ~32% higher water imbibition, and up to ~35–38% increases in shoot and root lengths. Chlorophyll content also improved significantly, with increases of ~19% in sorghum (10 min PAW) and ~23% in pearl millet (15 min PAW). Results suggest that PAW can serve as a sustainable pre-sowing and irrigation technology to improve seed vigor and early growth of millets, contributing to food security and resilience in semi-arid agroecosystems.
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