Title : Low-temperature atmospheric ressure plasma: An emerging green technology for improving agricultural productivity
Abstract:
The grand challenge of feeding nearly 10 billion people by 2050 requires that agriculture overcome several destabilizing factors, including the most challenging climate-change occurrences, to food and water security. Agricultural production must innovate environmentally friendly green technologies to improve crop productivity and ensure the sustainable production of nutrient-rich and disease-free foods during the climate change era. Low-temperature plasma (LTP) is a partially ionized gas with unbound electrons, ions, neutral particles, reactive nitrogen species, reactive oxygen species, and ultraviolet light. Low-temperature plasma is emerging as a viable non- chemical tool for seed priming to break seed dormancy, hasten seed germination, improve crop productivity, and disinfect seeds and foods, among many other uses. This research assessed LTP for (1) utilization for improving crop productivity through early seed germination, crop growth, drought tolerance, and biomass production using microgreen crops and mustard greens and (2) ensuring food safety by eliminating seed-borne pathogens. (i) Improving crop productivity using LTP: The mustard greens seeds were exposed to Argon (Ar) or Helium (He) gas LTP (at a fixed power setting of 6 kV, 1 μs pulse width, and 6 kHz) for T0=0 s (Control), T1=30 s, T2=60 s, and T3=90 s. The treated seeds were grown in pots containing potting mix at two seeds/pot and placed in a greenhouse. Seed germination, germination rate, plant height, and root length were recorded. Ar or He LTP increased the total seed germination by an average of 25% over the Control; the seedling height of Ar or He LTP-treated seedlings was, on average, 40% taller than that of the Control; fresh seedling biomass was double that of the Control in He LTP-treated seeds, and Ar LTP 30 s treatment, increased the root length by nearly 17% over that of Control. Faster seedling growth without compromising seedling biomass and an increase in root length indicate improved drought tolerance through shorter crop growing duration and increased root length for exploring larger soil volume for moisture and nutrients during drought stress. ii) Controlling seed-borne pathogens using LTP: Stemphyllum botryosum on spinach and Xanthomonas campestris Var. vesicatoria on bell pepper: This study assessed the effectiveness of low- temperature plasma in suppressing the seed-borne fungus S. botryosum and bacterium Xanthomonas campestris pv. vesicatoria (Xcv), cultures obtained from the American Type Culture Collection. The cultures were grown in the lab aseptically on nutrient agar and broth. The S. botryosum was directly treated with or without LTP, and Xcv cells were treated with argon gas LTP at 6kV and 8kV with a flow rate of 1.41 each at 4, 6, and 8 minutes. The mycelial growth was reduced by >50%, and LTP inhibited conidia formation. The SEM analysis showed that X. campestris cells were more unified in small rod shapes in the Control. In contrast, the LTP- treated bacterial cells became curvier, swollen, and aggregated, and destruction of cell walls in some bacterial cells. This research was supported by NSF EPSCoR RII Track 1 Grants OIA – 1655280 and 2148653 and NASA EPSCoR 80NCCS21M0139.
Audience Take Away Notes:
- This presentation will provide the audience with a research-based proof of concept of an emerging environmentally friendly, chemical-free technology for ensuring early seed germination and uniform plant establishment, improving plant growth and yields, and controlling seed-borne diseases
- The audience can initiate this research to improve different agricultural and horticultural crops
- Use the technology to train students in technology-based innovative agriculture to solve food problems
- This technology has the potential to generate liquid nitrogen that can be applied to crops through fertigation
- Integrate this technology to develop chemical-free control of plant diseases and improve the storage life of perishable foods, including fruits and vegetables
- This is an emerging technology with potential for a myriad of applications in agriculture
