Seed dormancy and surface-borne pathogens present significant challenges to uniform crop establishment and global agricultural yield. Traditional chemical disinfection methods raise severe environmental and safety concerns, increasing the critical need for sustainable, physical alternatives. This study proposes and evaluates a novel, hybrid dual-priming approach combining water-spray conditioning with cold atmospheric plasma to simultaneously break seed dormancy and achieve surface sanitation. Dormant agricultural seeds were subjected to a spray of water. Immediately following this, the seeds were treated using a dielectric barrier discharge plasma system for up to 20 minutes using atmospheric air as the working gas. The combined Plasma-UV treatment seemed to have a positive effect on the disinfection of \textit{Xanthomonas campestris pv. campestris} (Xcc), drastically reducing the seed-borne bacterial load without compromising internal embryo viability. However, evaluation against Alternaria (Abco) revealed clear limits to this synergy; while initial microbial reductions occurred, the protocol failed to achieve complete eradication of this highly resilient pathogen. Furthermore, extending the plasma exposure time up to 20 minutes yielded no statistically significant differences in survival rates across either pathogen group. These findings indicate that while a hybrid Plasma-UV system offers a rapid, highly effective alternative for specific surface-borne bacteria like Xcc, its capacity is bound by pathogen-specific resistance profiles and micro-fissure shielding within the seed coat, necessitating further optimization of plasma power densities.
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Seed-borne pathogens present a significant threat to agricultural productivity, with severe infestations potentially leading to food shortages. Although chemical pesticides remain the predominant method for seed disinfection globally, their environmental impact necessitates the exploration of sustainable alternatives. This project presents the development and evaluation of an eco-friendly ultraviolet-C (UVC) irradiation system designed to provide targeted, uniform germicidal radiation at a peak wavelength of 265 nm. The system was tested on cabbage seeds infected with Xanthomonas campestris pv. campestris and Alternaria brassicicola using a PWM-driven circuit to apply various duty cycles. It was also designed to integrate with a plasma unit and high-voltage supply developed by collaborating subgroups. Experimental findings indicate that UVC treatment alone can suppress pathogen growth, with duty cycles of 30% and 50% occasionally delivering germicidal efficacy comparable to continuous-wave exposures. ... Read more

As a novel alternative for conventional seed disinfection methods, a new design has been proposed in this report using a surface dielectric barrier discharge (SDBD) fractal electrode. The discharge mechanism for this electrode is a diffuse microdischarge under AC or short-pulsed DC mode operation. In this way, cold plasma could be generated that is applicable for seed disinfection. Furthermore, the electrodes were designed to be part of a proof of concept fluidized bed reactor with a reactor size of 10×20×20[𝑐𝑚] for disinfecting cabbage seeds with a diameter of 2𝑚𝑚. Because of this application, the efficacy of seed decontamination using plasma with its generated reactive agents was discussed. The used gas mixture in which the electrodes created plasma was ambient air without increased humidity. This means that the main reactive agents for sterilisation are reactive oxygen species (RON) like ozone (O3) and reactive nitrogen species (RNS). The electrical and physical parameters required to make cold-plasma were investigated to come up with a proper design for the electrode. From this theoretical analysis, five different initial designs emerged. The analysed designs include a wire-to-wire, wire-to-sheet, multi-hollow DBD, fractal SDBD and a coplanar DBD fractal electrode. All electrode designs were made based on the state-of-the-art dielectric barrier discharge principle. Moreover, in the design consideration, different materials for the conductor and dielectric were discussed, mainly based on electrical properties, plasma generation and manufacturing possibilities were considered. Based on previously set trade-off requirements, together with the results of measured power and turn on voltage of the plasma electrodes, the best designs tested design for seed disinfection are the double-sided 5𝑡ℎ order Hilbert fractal with a 1.6 𝑚𝑚 barrier and the single-sided 5𝑡ℎ order Hilbert fractal with a 0.8 𝑚𝑚 barrier. ... Read more