Review—Seed Treatment: Importance, Application, Impact, and Opportunities for Increasing Sustainability

Abstract

Climate change, soil degradation, and the spread of seed-borne pathogens pose serious challenges to global food security and agricultural sustainability. Although chemical seed treatment provides pathogen control, it poses environmental and health risks. This review analyses innovative seed treatment technologies, with particular emphasis on ozonation as an ecologically viable alternative. The mechanisms of action of ozone, its effects on seed germination, reduction of microbial contamination, and crop establishment are discussed. Chemical, physical, and biological treatment methods are comparatively evaluated, analyzing their effectiveness, environmental impact, and application limitations.

1. Introduction

Global food security and sustainability challenges have become one of the most important global topics. The growing world population, climate change, and ecosystem degradation are increasing the pressure on agriculture to ensure a sufficient and safe food supply. According to FAO [1], millions of people worldwide suffer from hunger and malnutrition every year, and FAO [2] predicts that by 2050, the world population will increase to 9.7 billion. In order to meet these needs, food production will have to increase by at least 60%. Extreme events caused by climate change, the spread of pathogens, and soil degradation reduce plant productivity. Rozewicz et al. [3] indicate that fungal diseases cause 15–20% of crop losses, and in some cases, even up to 50%. Fisher et al. [4] emphasize that resistance to fungicides is increasing. This raises the need to find sustainable alternatives. One of these is innovative seed treatment technologies, including ozone treatment.

Therefore, in order to ensure plant health and reduce the use of synthetic chemicals, it is necessary to develop innovative, environmentally friendly seed treatment technologies. In the context of modern agriculture, seed treatment is becoming one of the most relevant technologies, which can significantly contribute to plant health, productivity, and sustainable production. One of the most promising measures is ozonation, which, due to its strong oxidative effect, can become an alternative to conventional chemical fungicides and contribute to the implementation of the EU Green Deal goals. Guo and Wang [5] argue that ozone does not leave residues in products because it can easily decompose into non-toxic products, mainly diatomic oxygen, and its half-life is very short, making it an alternative raw material treatment to conventional chemicals commonly used for seed disinfection and other agricultural procedures. Studies by Cetinkaya et al. [6] have shown that ozone can effectively reduce the number of microorganisms, such as bacteria, fungi, and viruses, while not harming seeds and plants. Sanchez et al. [7] observed that ozone not only helps protect crops from disease but also promotes seed germination, making it an increasingly popular solution in sustainable agricultural practices.

Sivaranjani et al. [8] state that ozone is an environmentally friendly and cost-effective, non-thermal food processing technology, which is also called a “green” technology because it has the least negative impact on the environment. Ozonation can be widely applied to microbial decontamination and mycotoxin degradation in grains, and it increases seed germination. Acting as a natural oxidant, it can help reduce the use of chemical pesticides and environmental pollution, becoming a more sustainable alternative in agriculture and contributing to food production practices. Pandiselvam et al. [9] note that this technology is environmentally friendly and does not leave any by-products. According to them, it is one of the promising, environmentally friendly technologies that can contribute to improving food safety and quality. It can be concluded that this is in line with the EU agricultural and food policy, which aims to reduce the use of chemicals and promote sustainable agricultural practices [10]. The aim of this article is to review the importance, application possibilities, and impact of innovative seed treatment technologies on plant health and yield, with particular attention to ozonation as a promising ecological alternative in the context of sustainable agriculture.

2. Application of Existing Seed Preparation and Processing Technologies, Their Impact on Plant Growth, Quality, and the Environment

Seed preparation and treatment are important stages of agricultural production, directly influencing seed germination, plant health, productivity, and overall crop quality. Various technologies are used for this: chemical, biological, and physical treatment, each of which has its own advantages and disadvantages, i.e., different effects on seeds and their germination, pathogen control, and plant development. Their effectiveness depends on the type of seed, environmental conditions, and the desired results. Since each technology has specific mechanisms of action and application possibilities, it is important to assess their impact not only on seed germination but also on overall plant productivity and sustainability.

Seed treatment is the process of preparing seeds for sowing to ensure better germination, growth rate, and disease resistance. Hozzein et al. [11] state that the use of high-quality seeds is one of the main conditions for obtaining high yields. However, good quality seeds can only be ensured by taking appropriate measures against diseases, especially those that are spread through seeds.

Studies show that seed treatments can reduce oxidative stress and improve plant resistance. For example, Rady et al. [12] conducted studies on wheat and found that pre-sowing seed treatment reduced oxidative stress in seeds. Iqbal et al. [13] observed that pre-sowing seed treatment significantly improved germination, growth, and enzymatic activity in melon seeds. Sekmen Cetinel et al. [14] in their studies on wheat seeds found that pre-sowing seed treatment made the seeds more resistant to deeper embedment, making this method particularly important in dry areas. Mulvaney et al. [15] also showed that pre-sowing treatment of wheat seeds increased early-season plant density and grain yield even under dry growing conditions.

Continuous climate change and increasing food demand encourage the search for more effective seed treatment methods that would not only help maintain yield but also ensure its increase. Cereal plants must adapt to climate change, but without the attention and research of scientists, this would be difficult to do. After analyzing scientific research on seed treatment, several seed treatment methods can be distinguished, which have recently been gaining more and more attention.

The following will review the most popular seed treatment technologies: mechanical; chemical treatment: staining, fungicides, insecticides, etc.; physical treatment: electromagnetic waves, ultraviolet light (UV), ozonation, plasma, and biological seed treatment methods (treatment with microorganisms and plant extracts).

2.1. Chemical Seed Treatment and Environmental Impact

Chemical seed treatment has become a vital component of modern agriculture. It aims to improve seed germination, productivity, and protection against diseases, pests, and environmental stress. Fungicides, insecticides, trace elements, and structural protection agents are widely used for these purposes.

Chemical seed treatment, including various forms of dressing and the use of growth regulators, fungicides, insecticides, and other safeners, is a key strategy in modern agriculture to improve seed quality, germination, and overall plant health [12,16,17,18]. Chemical treatments can effectively address a number of agronomic problems, especially during critical early stages of plant growth. For example, the use of growth regulators has been shown to significantly increase grain yield and protein content in soft winter wheat. This effect is attributed to the enhanced physiological responses induced by such treatments [19]. Similarly, the use of iron-coated seeds in rice has improved growth parameters and soil properties, suggesting that chemical treatments can increase yields and resource utilization in production systems [20].

Fungicides, such as fludioxonil, carbendazim, or thiram, are used to protect seeds from fungal pathogens and promote germination [21,22,23]. Insecticides, such as imidacloprid, help reduce pest pressure, especially during the seedling development stage [24,25]. Combined use of fungicides can increase seedling viability and ensure more stable yields even under suboptimal conditions [26].

The results of specific studies show the effectiveness of chemical seed treatments and their dependence on the applied active ingredients and their doses. For example, Catão et al. [27] showed that treating soybean seeds with a fungicide mixture containing fipronil, pyraclostrobin, and thiophanate-methyl (0.5–0.25–0.225 g/kg, respectively) increased antioxidant activity and reduced phytotoxicity. Mayton et al. [28] evaluated biological, biochemical, and chemical seed treatments (20CU_2697LQ; AmplitudeTM; Bio SeedTM; Varnimo/KaPre Embrella; Phyter; Ultim^®; Prudent 44^®/Nutrol^®; Apron XL^®/Maxim^® 4FS 1/2X, 4FS 1X, 4FS^® 2X; Apron XL^®/Maxim^®4FS/Mertect^® 340F 1X) for the treatment of hemp seeds and found that the chemicals and the biochemical, based on organic copper, prevented turbidity and improved plant establishment. Meanwhile, samples treated with biological preparations did not differ from controls in terms of disease incidence or growth results. Silva et al. [29] showed that corn seeds treated with carboxin + thiram (2 g/kg) maintained high quality during storage. Penido et al. [21] studied coffee seed treatment with Vitavax-Thiram 200 SC (3 mL/kg) and found an approximately 10% increase in germination after 6 months of storage. Meanwhile, Couto et al. [30] found that soybean seeds treated with thiamethoxam or fipronil-based products exhibited higher electrical conductivity, which may indicate viability impairment.

Chemical seed treatment includes not only protection against diseases and pests but also the ability to improve the physiological properties of seeds, especially resistance to environmental stress. Studies show that some chemicals, including growth regulators or phytohormones, can promote germination and early growth even under adverse conditions. In addition to conventional dressings, more and more attention is paid in the literature to more advanced treatment technologies. Among them, two significant ones are distinguished: priming and granulation, which, although similar at first glance, differ in their purposes and principles of action. Priming is a physiological method of seed preparation, when they are briefly immersed in solutions of active substances (e.g., melatonin, polyamines, hydrogen peroxide) in order to activate metabolism and improve germination and stress resistance [31,32]. This method allows seeds to initiate physiological processes before radicle emergence and is particularly useful for poorly germinating batches or when sowing under adverse conditions [33,34]. Depending on the solution used, priming is divided into hydro-, osmo-, halo-, or solid matrix forms. For example, hydro-priming promotes hydration and metabolic activation [35,36], while osmo-priming, using osmotic solutions (e.g., polyethylene glycol), allows for the initiation of water uptake without germination [34,37]. Osmo-priming has also been shown to be effective in improving seed viability and germination under stressful conditions [38,39]. Similar positive effects have been confirmed in studies with peas under saline conditions [40]. Halopriming has also improved growth in species exposed to salt stress [41,42]. This method is also often used in combination with fungicides, fertilizers, or growth stimulants, so granulation has multifunctional protective and technological benefits [23].

Chemical seed treatments have also been associated with increased yields. Chemical seed treatments have been shown to have a positive effect on crop fertility and yield. The System for Wheat Intensification (SWI) reported increased yields due to optimal seed treatments, combined with practices such as seed rate adjustment and improved planting techniques [43]. Mengesha et al. [44] found that wheat seed treatments reduced disease incidence and increased yield. Furthermore, new treatments for corn, including the application of nano-copper, have been reported to increase germination and ultimately improve growth and productivity [45]. Similarly, Rocha et al. [46] and Silva et al. [29] showed that treated seeds had more uniform germination and longer seed viability. However, this effect is not unequivocally positive. Mengesha et al. [44] found that treatment of wheat seeds with the fungicide “Thiram + Carbofuran” reduced the incidence of Fusarium head blight by 27.40% and increased the yield (4.05 t/ha). In addition, a new technology for treating corn with metal nanoparticles (nano-copper-nCu) at a concentration of 20 mg/kg was reported to increase germination and ultimately improve growth and productivity [45]. Similarly, Rocha et al. [46] and Silva et al. [29] showed that soybean and corn seeds treated with fungicides and insecticides had more uniform germination and longer seed viability. However, this effect is not unambiguously positive.

Despite the advantages of chemical seed treatments, there are important environmental considerations to address. Some substances, especially when used in excess or inappropriately, can have negative effects on soil microbial communities, aquatic ecosystems, and non-target organisms. If chemicals are used inappropriately, phytotoxicity may occur [30]. Stains with systemic fungicides or insecticides can accumulate on the surface of seeds and then enter the soil or water bodies through root secretions [47]. The use of systemic insecticides, such as neonicotinoids, although effective in controlling certain pests, has raised concerns about their potential effects on non-target organisms, including pollinators [48]. Similarly, the use of synthetic fungicides has been reported to reduce microbial diversity in soil, which may have long-term detrimental effects on soil health and ecological balance [49]. Thus, in addition to commercial products, environmentally friendly formulations and biological stimulants are becoming increasingly relevant alternative solutions. For example, the use of nutritional additives as components of seed coatings can increase nutrient uptake [50]. Lamichhane et al. [51] and Hegde et al. [52] highlight that integrated pest management (IPM) strategies, combining chemical and biological measures, can help reduce environmental damage. For example, Trichoderma spp. and plant extracts can be beneficial when combined with chemical treatments [53,54]. There is increasing attention to sustainable practices, promoting biopesticides and organic treatments to reduce these negative impacts. Studies show that plant extracts and biofertilizers can be effective alternatives to synthetic chemicals, offering disease control and lower environmental impact compared to conventional agrochemicals [55].

In conclusion, although chemical seed treatment is very important in increasing crop yields and protecting them from diseases and pests, its impact on the environment and human health cannot be ignored. In order to reconcile agricultural productivity with environmental protection, it is necessary to tighten the regulation of pesticide use and move towards more sustainable agricultural practices, integrating biological, ecological, and physical alternatives.

2.2. Physical Seed Treatment and Environmental Impact

Physical seed treatment methods, such as ozonation, ultraviolet (UV-C) light, laser, magnetic field, electromagnetic waves, low-energy electron beam (LEEB), or cold plasma, are becoming increasingly relevant technologies in agriculture. They are designed to destroy pathogens, improve seed germination, promote growth processes, enzymatic activity and yield. They also reduce pollution and contribute to sustainable practices. The main technologies, seed types, experimental parameters, and the described effects are presented in

Table 1. The effect of physical seed treatment technologies on germination, growth parameters, and physiological indicators.

Technology	Seed Type	Technology Parameters (Intensity, Power, etc.)	Time of Exposure	The Effects	Reference
He-Ne laser	Celosia argentea plant seeds	650 nm, 50 mW	0, 5, 10, 15 min	The most effective exposure times—10 and 5 min The number of branches, root length, vase life, free fatty acid profile, total phenolic, flavonoid, and tannin compounds, and antioxidant activity of methanol extracts of C. argentea improved.	[56]
He-Ne laser	Wheat seeds (Triticum aestivum L.)	632.8 nm (power density—5.43 mW)	3 min	Laser application combined with drought stress significantly improved relative water content, protein, and photosynthetic pigment concentrations.	[57]
He-Ne laser	Wheat (Triticum aestivum L. cv. S-24)	632.8 nm; at 100, 300, and 500 mJ energy from the embryonic area side	-	Radiation at 500 mJ increased germination energy, germination percentage, germination index, α-amylase, and protease activity. Radiation at 300 mJ shortened the mean emergence time and 50% germination time.	[58]
He–Ne laser Argon laser irradiation	Wheat seeds (Triticum aestivum L.)	633 nm (10, 20, 40, 60 mW) 514.5 nm (10, 20, 40, 60 mW)	0.5, 1, 2, 4, 6 h	Significantly stimulates the growth and germination of seeds, positively affecting their physiological and biochemical properties. Increased the amount of plant pigments (chlorophyll a, chlorophyll b, and carotenoids).	[59]
Semiconductor laser	Rice seeds (Pyongyang-53; Dongsung-1)	650 nm; 5 mW, duty ratio of 50%	0.05–0.28 s	The yield of Pyongyang-53 and Dongsung-1 increased by 7.7% and 21%, respectively. Pre-sowing treatment can significantly improve germination, seedling growth, and rice yield.	[60]
Magnetic field (MF)	Melon seeds (Cucumis melo L.)	100 mT, 200 mT	5–20 min	Germination (+14.6%), root, and shoot length (+36.4% and +22.8%), viability indices (+40.6% and +28.8%), biomass, leaf area (+9.6%), α-amylase (+12.9%), protease (+50.0%), catalase (+80.0%), and chlorophylls a/b (+92.5%/+36.5%) increased, while the average germination time was shortened by 6.7%.	[61]
Magnetic field (MF)	Bitter gourd (Momordica charantia L.; cv Faisalabad Long)	25, 50, 75 mT	15, 30, 45 min	The treatment increased germination (up to +54.5%), viability index (+24.9% and +47.2%), and growth parameters: leaf area (+64.6%), root, and shoot biomass (+23–76%), chlorophyll (+35.4%), fruit length (+18.1%), mass (+14.9%), and yield (+29.2%).	[62]
Magnetic field (treated water)	Turnip seeds (Brassica rapa L.)	211 mT	30, 45, 60 min	Germination increased to 28.3%, germination rate—11.5%, viability—57.6% and 32.3%. Longer seedlings, higher biomass, more chlorophyll, protein (+28.9%), α-amylase (+11.4%) and protease (+14.8%).	[63]
Magnetically (treated water)	Common bean (Phaseolus vulgaris L.)	100–150 mT	30 min	Germination increased by 25%, while stem length, viability index, leaf area, and seed weight increased by 35, 100, 109 and 16%, respectively. Chlorophyll a, b, and carbohydrate content increased by 13, 21, and 26%.	[64]
Magnetic field (Magnetized + magnetized water)	Tomato	273 nm, water magnetization capacity—4–6 m3/h	-	Magnetic seed and water treatment improved tomato growth, increased proline and chlorophyll content, and reduced the effects of water deficit, especially at 40–60% field capacity.	[65]
Magnetic field	Corn seeds (Ramda variety)	125, 250 mT	1 min, 10 min, 20 min, 1 h, 24 h, continuous exposure	The treatment shortened the average germination time and accelerated germination (10–90%), with the greatest effect achieved at a field of 125–250 mT.	[66]
Weak sinusoidal and extremely low-frequency (ELF) magnetic field	Cress seedlings (Lepidium sativum L.)	50 Hz, 100 μT	12 h	The treatment reduced the effects of heat stress, and the oscillating magnetic field acted as a protective measure under certain conditions without causing a direct change in growth.	[67]
Electromagnetic radiation (EMR) + plasma	Seeds of wheat (variety UP 2565)	100 mT, 25.6 V 200 mT, 44.3 V 13.56 MHz, 50 W, 0.7 mbar	1 h 6 min	All stimulation methods improved wheat germination and growth. After 6 and 12 h, water absorption increased by 42.2% and 23.9%, respectively, and the highest germination was achieved with 200 mT EMR. Plasma-treated seeds germinated the earliest and fastest.	[68]
UV-C light Chlorine	Soybean and amaranth sprouts	- 100, 200 ppm	2.5, 5, 10, 15, 20, 30 min 15 min	The 15 min treatment increased the content of phenols and flavonoids in the sprouts—in soybeans, apigenin derivatives up to +237%, in amaranth, p-coumaroylquinic acid +17.7%, without causing color changes.	[69]
UV-C irradiation	Winter wheat seeds (Triticum aestivum)	253.7 nm, 20 W, intensity—60 W/cm2	0, 15, 30, 60 min	A 15 min treatment promoted germination of infected wheat seeds and reduced the levels of fumonisins and beauvericin, but longer irradiation increased the levels of enyathins.	[70]
Gas plasma-activated water (GPAW)	Arabidopsis thaliana (L.) Heynh	Air and He/O2 mixture (98% He, 2% O2) + high voltage plasma (8.5 kV and 29.3 kHz)	100 ms pulses, 30% duty cycle	GPAW promoted dormancy breaking through the interaction of reactive compounds with hormone metabolism and cell wall remodeling, weakened the endosperm, and improved seed quality.	[71]
RF plasma	Spring wheat (Triticum aestivum L.), narrow-leaf lupine (Lupinus angustifolius) and corn (Zea mays L.)	5.28 MHz, air atmosphere at a pressure—40–80 Pa	2–10 min	The highest biological efficiency was achieved at a specific discharge power of 0.35 W/cm3 and 5–7 min exposure, when active plasma particles changed the morphology of the seed coat.	[72]
RF plasma	Moringa oleifera seeds	100 W, 2 torr air gas pressure	0, 1, 5, 10, 15 min	The greatest effect was achieved after treating seeds for 1 min—germination, root, and shoot length (4.3–26.4%), and biomass (4.9–6.9%) increased.	[73]
Radiofrequency cold plasma	Corn (Zea mays subsp. Mays), wheat (Triticum aestivum), barley (Hordeum vulgare), and psyllium (Plantago ovata)	13.5 MHz, 50 W	15, 30, 60, 90 min	The treatment increased the rate and amount of water uptake by the seeds, and modeling confirmed a mechanism consistent with the microscopy and staining results.	[74]
Atmospheric dielectric barrier discharge (DBD plasma) + gaseous ozone + NO2	Wheat seeds (Xiaoyan 22)	13.0 kV 1.17 mg/L 0.11 mg/L	4 min	The treatment increased wheat germination potential (+27%) and growth, reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), and promoted abscisic acid (ABA) synthesis and expression of the genes LEA1, SnRK2, P5CS.	[75]
Atmospheric pressure plasma Plasma-activated water	Wheat seeds (Triticum aestivum)	50 Hz, 0–45 kV	1, 2, 3, 4, 5 min 5, 10, 15 min	The treatments improved germination rate and productivity—3 min direct plasma provided the highest germination rate, while 15 min PAW provided the best results. Longer treatments reduced wettability and contact angle.	[76]
Atmospheric pressure gliding arc discharge plasma (H2O/air plasma; H2O/O2 plasma; H2O/O2/air plasma)	Wheat seeds (Triticum aestivum)	5 kV. RNS–N2 transitions (294–380 nm, 391–405 nm) and OH radicals (309.02 nm); OH (309.02 nm) and O radicals (777.42 and 844.34 nm). A mixture of O2 (75%), air (20%); H2O (5%), was used to form ROS and RNS.	3, 6, 9, 12, 15 min	Six minutes of H2O/O2 plasma treatment ensured 95–100% germination and ~20% higher yield, while 3–9 min improved growth activity, biomass, chlorophyll, spike length, and protein content.	[77]
Atmospheric pressure non-thermal plasma (APNTP)	Khandagiri paddy seeds	15 kV, 19 kV	0.5, 1, 2, 3, 4, 5, 7, 10 min	Complete seed disinfection was achieved within 10 min, and after 1–5 min, the CFU significantly decreased. The treatment improved wettability, water uptake, viability, and growth rates.	[78]
Atmospheric plasma	Mulungu seeds (Erythrina velutina)	10 kV, 750 Hz, 150 W, helium gas flow—0.03 L/s	60 s	Treatment with ~5% accelerated germination, improved hydrophilicity, and water absorption, especially in the hilum area, thereby promoting seed germination.	[79]
Atmospheric pressure plasma Low-pressure plasma	Brassicaceous seeds	10 kV, 10 kHz, the argon gas flow rate—3 L/min 5.5 kV, 10 kHz, the argon gas flow rate—0.5 L/min, pressure in the chamber—80 torr	2, 5, 10, 20, 40 min	Ten minutes of atmospheric plasma reduced R. solani survival to 3% but slowed germination. Low-pressure plasma reduced survival to 1.7% without a significant effect on germination and was more suitable for seed disinfection due to lower temperatures.	[80]
Atmospheric plasma	Pityrocarpa moniliformis seeds	10 kV, 400 kHz	1.5, 2, 3, 4, 5 min	Treatment (4–5 min) increased seed wettability, cumulative germination (+30%), and viability (38% vs. 12%). Treatment helped overcome seed coat dormancy and improved germination.	[81]
Atmospheric pressure air plasma	Andrographis paniculata	3400, 4250, 5100, 5950 V	10, 20 s	Treatment (5950 V, 10 s) increased seed permeability, accelerated germination, seedling emergence, and enhanced antioxidant protection (↑ catalase activity, ↓ MDA). 4250 V/10 s and 5950 V/20 s improved germination, while 3400 V/20 s and 5100 V/10 s reduced permeability and delayed germination.	[82]
Atmospheric gliding arc discharge plasma	Astragalus membranaceus seeds	40 kV, 270 W	30–270 s	A 90 s treatment destroyed >98% of F. oxysporum spores, and 270 s—completely. Treatments of 30–90 s—stimulated germination.	[83]
Atmospheric plasma jet	Honeydew melon seed (Cucumis melo L.)	1.0, 1.1, 1.2, 1.3, 1.4 kV	10, 20, 30, 40, 50 s	Plasma (1.4 kV, 10 s) increased seed germination rate by 20.6–89.6% and improved hydrophilicity.	[84]
Dielectric barrier discharge (DBD) at atmospheric pressure	Radish seeds (Raphanus sativus)	50 Hz, 11.32 kV (rms). Argon gas with a flow rate—2 L/m	1 to 5 min	DBD plasma treatment (2–3 min) improved germination, viability index, carotenoid content, and seedling biomass, and increased hydrophilicity and water uptake, but the overall production rate decreased.	[85]
Dielectric barrier discharge plasma (DBD plasma)	Wheat seed (Xiaoyan 22)	0.0, 9.0, 11.0, 13.0, 15.0, 17.0 kV. Air flow rate—1.5 L/min	4 min	Treatment (11.0 kV) increased germination potential (+31.4%), germination index (+13.9%), and viability index (+54.6%), and improved shoot and root growth, water absorption, protein systematization, and α-amylase activity.	[86]
Low-temperature plasma (LTP)—Diffuse Coplanar Surface Barrier Discharge (DCSBD)	Corn seeds (Zea mays L.)	14 kHz, ~10 kV	60, 120 s	LTP treatment (60 s) increased root length and biomass, while 120 s inhibited growth. Catalase (CAT) and peroxidase (G-POX) activities decreased, superoxide dismutase (SOD) slightly increased, and dehydrogenase (DHO) increased in embryos but decreased in roots.	[87]
Low-pressure plasma	Corn seeds (Zea mays L.), narrow-leaved lupine (Lupinus angustifolius L.) and winter wheat (Triticum aestivum L.)	5.28 MHz, pressure—200 Pa	2, 4, 5, 7 min	The treatment reduced fungal diseases (e.g., lupine root rot from 47.8% to 6.9%) and enhanced plant resistance. Yields increased: wheat by 2.3%, corn by 1.7%, lupine by 26.8%, and the content of non-enzymatic antioxidants in corn roots increased.	[88]
Low-pressure plasma (LPRF) Dielectric barrier discharge (DBD) plasma Jet of argon plasma	Sunflower seeds (Helianthus annuus L.)	75, 100, 125, 150 W, 1.65 Pa pressure, 3.56 MHz frequency 90 W 0.41, 0.51 W, 0.61 W, and 0.72 W power, 4 L/min argon flow.	2 min 30, 60, 90, 120 s 15 s	As plasma power increased, wettability, water absorption, and germination rate improved, and biological changes were associated with surface alterations.	[89]
Non-thermal plasma	Wheat seeds (Triticum aestivum)	50 Hz, the air flow rate was 1 L/min	5, 15, 30 min	On the fourth day of germination, germination rate was not significantly affected, but root length, seedling mass, and R/S ratio were increased (from 0.88 ± 0.016 to 1.2 ± 0.005).	[90]
Plasma and radio-wave	Legumes and grain-crops seeds (Lupinus angustifolius—blue lupine, Galega virginiana—catgut, Melilotus albus—honey clover and soy)	5.28 MHz, pressures—0.3–0.7 Torr, specific RF power ~ 0.6 W/cm3	5, 10, 15, 20 min	For 10–15 min, both treatments increased seed germination by 10–20% and legume yields by 14–24%, and reduced fungal infections by 3–15% (except anthracnose). Durations >15 min inhibited germination.	[91]
Cold atmospheric-pressure plasma (CAP) Low-energy electron beam (LEEB)	Lentil seeds	0%—16.15 kHz, 535.5 W; 50%—14.55 kHz, 693.5 W; 75%—13.84 kHz, 776 W; 100%—13.335 kHz, 858.5 W 4–30 kGy, 180 kV	0–10 min 100 ms	Both technologies inactivated microorganisms, but cold plasma was more effective (5 log vs. 3 log), promoting germination and increasing wettability without tissue damage, while electron beam (≥8 kGy) caused root anomalies.	[92]
Atmospheric cold plasma (ACP)	Wheat and barley grains	80 kV	5, 20 min	A 20 min ACP treatment reduced the barley microbiota to 2.4 log10 CFU/g for bacteria and 2.1 log10 CFU/g for fungi, but impaired germination. Shorter (≤5 min) treatment was safe for germination.	[93]
Cold plasma (low pressure)	Bambara seeds (Vigna subterranean) Chilli (Semerah) Papaya (Eksotika)	13.56 MHz, ultimate pressure of 1.5  ×  10−3 Torr. 10 W, pressure increased to 35 Pa. 80 W, pressure increased to 40 Pa. 80 W, pressure increased to 40 Pa	10 s 60 s 40 s	After treatment, the contact angle of Bambara seeds decreased from 114° to 44°, water absorption and electrical conductivity increased for all seeds, with the best changes remaining for the first 30 days.	[94]
Cold plasma	Wheat and oat	500 W, air flow rate—200 mL/min	0–2400 s	The treatment eroded the wheat seed coat, temporarily retarded germination, but promoted stem growth. In oats, germination was not affected, but it promoted root formation. Changes in phenolic compounds indicate metabolic changes due to plasma exposure.	[95]
Cold plasma	Soybean seeds (Glycine max L. Merr cv. Zhongdou 40)	13.56 MHz, 0, 60, 80, 100, and 120 W, pressure—150 Pa	15 s	Treatment (80 W) increased soybean germination (14.7%), viability (63.3%), water absorption (14%), and reduced contact angle (−26.2%). Shoot and root growth and reserve utilization were improved, especially the development of the underground part was promoted.	[96]
Cold plasma (CAP)	Cotton seeds	38 kVpp for air and 11 kVpp for argon plasma. 1 L/min flow.	0.3 min (air plasma) 27 min (air plasma) 81 min (argon plasma)	A 27 min air treatment increased the water absorption, germination, cold and stress resistance of cotton seeds, and the effect persisted for 4 months, indicating long-term stability and industrial potential.	[97]
Cold plasma	Rapeseed seeds (Brassica napus L. cv. ‘Zhongshuang 11’)	100 W	15 s	The treatment reduced malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and catalase (CAT) activities and soluble sugars, improved root activity, photosynthesis, nitrogen uptake and yield, and enhanced drought tolerance.	[98]
Cold plasma	Basil seeds	Plasmajet	30 s	The treatment increased plant biomass, height and size, and leaf index, but did not significantly affect other morphological characteristics.	[99]
Cold plasma	Wheat grains	50 Hz, 0, 13, 15, 17 kV	0, 5, 10, 15 min	Treatment (15–17 kV, 5 min) increased wheat germination from 83% to 88.8%, accelerated germination, and shortened the average germination time. Treatment for too long or at 17 kV reduced the efficiency.	[100]
Microwave atmospheric plasma (MAP) jet Dielectric barrier discharge (DBD) plasma Low-pressure RF plasma Plasma activated water (PAW)	Corn seeds.	500 W 35 kHz, 15 kV 13.56 MHz, 800 W, 100 mTorr 800 W, 15 LPM He + 3 LPM	3 s 10 s 2 min 10 min	RF plasma increased yield but did not reach control levels. PAW slightly improved yield in unstable environments. MAP reduced yield at all sites (e.g., from 238.8 ± 8.7 to 221.3 ± 3.9 bu/acre).	[101]
Oxygen Plasma	Wheat seeds (Alixan, Genius, Nexera 88, Sofru, Bologna, Izalco, Amicus, and 88.5 R)	5 kW, 13.56 MHz	120 s	In the two-year study, the effects of plasma and other treatments were cultivar-specific, with no clear advantage identified, and germination was reduced in the 88.5R cultivar.	[102]
Glow (direct) or afterglow (indirect) low-pressure radio-frequency oxygen plasma	Winter wheat seeds (Triticum aestivum L. cv. “Ingenio”)	13.56 MHz, 200 W, 50 Pa	30, 90 s	Long-term low-pressure oxygen plasma treatment increased the hydrophilicity and water absorption of wheat seed surfaces, but slowed germination and reduced α-amylase activity.	[103]
Nanosecond-pulsed plasma	Melon seeds (Huangdanzi)	20, 22, 24 kV	3, 5, 7, 9 min	Plasma treatment (20 kV, 9 min) of A. citrulli-infected melon seeds improved seedling growth, the number of first true leaves increased 2.3-fold, and the disease index decreased by 60.5%.	[104]

Note: MF—magnetic field; DBD—dielectric barrier discharge; RF—radio-frequency plasma; ACP/CAP/APNTP/APPJ—atmospheric cold or non-thermal plasma (including atmospheric pressure plasma jet); PAW/GPAW—plasma-activated water or gas plasma-activated water; UV-C—ultraviolet C-type radiation; MAP—microwave atmospheric plasma; DCSBD—diffuse coplanar surface barrier discharge; LPRF—low-pressure radio-frequency plasma; SOD—superoxide dismutase; CAT—catalase; POX—peroxidase; ROS—reactive oxygen species; RNS—reactive nitrogen species; ABA—abscisic acid; CFU—colony forming units.

.

According to the research data presented in Table 1, laser technologies, especially He-Ne and semiconductor lasers, have biological efficacy. Studies show that they can promote germination, seedling growth, enzyme activity, plant productivity, and metabolism during germination [56,57,58,59,60].

Magnetic fields also have positive effects on plants. They improve germination rate, leaf area, shoot and root growth, enzyme activity, and show positive effects on drought and salinity tolerance [61,62,63,64,65,66]. Effects on cellular bioelectric processes and metabolism have also been observed [67,105]. Haq et al. [63] found and emphasized that the activity of the enzymes α-amylase and protease increases, which is directly related to seed nutrition and energy utilization. Sharma et al. [68] additionally showed that electromagnetic radiation (200 mT) can act as a growth stimulant, and plasma-treated seeds showed the highest germination in their study.

Low-energy electron beam (LEEB), although effective in inactivating microorganisms, has in some cases caused undesirable effects, such as root anomalies [92]. Therefore, this technology should be applied with caution.

UV-C light is a non-thermal method that can inhibit mycotoxins and pathogen development, promote the synthesis of antioxidants and bioactive compounds, and improve seed quality [69,70,71,106,107,108,109]. In addition, UV treatment promotes the synthesis of antioxidants and bioactive compounds, increasing stress resistance, but to maximize this benefit and minimize the potential damage from excessive UV radiation, it is necessary to regulate the duration and intensity [106].

One of the fastest-developing technologies is the application of cold plasma. Plasma is a partially or fully ionized gas containing ions, electrons, and neutral particles [110]. The energetic fields generated by plasma promote the formation of oxidizing radicals, which can cause oxidation and degradation of surface molecules [111], effectively disinfecting seeds [93]. This technology modifies the seed surface at the biochemical level and affects the physical and chemical properties, increasing hydrophilicity, accelerating water uptake, and activating physiological processes [5,74,77,79,86,93,94,102,103,111,112]. An increase in seed permeability enzymes, antioxidants, and phenolic content in the roots of seedlings has been observed, indicating greater resistance to stress during vegetation [88,89,96], as well as improved germination and growth parameters [78,81,90,97,98,99,113]. Tong et al. [82], Gidea et al. [100], Guragain et al. [85], Halim et al. [84], Guo et al. [104], and Mukherjee et al. [78] also found that plasma reduces pathogen load. Some studies have shown increased resistance to drought, salinity, cold, and heavy metal stress, as well as increased electrical conductivity [94,102,114]. Filatova et al. [72] argue that the response of seeds depends on the properties of the plasma, power, gas type and pressure, while Henselova et al. [87] emphasize that the critical factor is the duration of treatment—too short a time leads to a weak effect, while too long can be harmful to the seeds. It is claimed that plasma application can reduce the dependence on chemical fertilizers and pesticides (including fungicides), thus contributing to the reduction of environmental toxicity [83,101,115].

One of the most advanced methods is the application of cold plasma. Plasma is a partially or fully ionized gas containing ions, electrons, and neutral particles [110]. Cold plasma technology is increasingly recognized for the decontamination of pathogens in agriculture [78]. The energy fields generated by plasma promote the formation of oxidizing radicals, which can cause oxidation and decomposition of surface molecules [111], effectively disinfecting seeds [93]. According to Qiao Guo et al. [75] and Los et al. [93], treatment with dielectric barrier discharge (DBD) plasma significantly increases the germination of wheat seeds, improves their water uptake, and the increase in surface hydrophilicity accelerates germination. Plasma changes the physical and chemical properties of the seed coat, which has a long-term effect on growth processes [5,75,77,79,94,102]. According to Zhang [112] and Starič et al. [103], low-temperature plasma modifies the seed surface at the biochemical level, thereby increasing seed viability and resistance.

Filatova et al. [91] note that seeds are a very complex biological system, and plasma treatment of seeds can affect it through various mechanisms—by modifying the seed coating and interacting with electrons, ions, radicals, and UV radiation released during the discharge [95]. Filatova et al. [72] summarize that the seed response depends on the properties of the plasma, power, gas type, and pressure. Henselova et al. [87] emphasize that treatment time is critical: too short a time causes a weak effect, while too long can damage the seeds.

Dobrin et al. [90] found that in all cases, plasma treatment (5, 15, 30 min) improved seedling and root growth, but the most effective was the 15 min effect. Filatova et al. [88] studied corn and recorded increased levels of non-enzymatic antioxidants—proline, anthocyanins, and phenols—in seedling roots, indicating greater resistance to stress during vegetation. Ling et al. [96] also showed that cold plasma improves hydrophilicity and seed permeability through surface etching and functionalization.

Ford et al. [74] experiments with barley showed that plasma increases the rate and amount of water uptake, and water movement depends on diffusion and the capillary system. This was also confirmed by Mukherjee et al. [78], who indicated that improved irrigation was associated with higher seed viability. Groot et al. [97] emphasized that plasma treatment promotes germination, root growth, and microbial resistance. Sarapirom and Yu [89] studied sunflower seeds and found that as plasma power increased, surface roughness increased, improving water contact and germination rate. Li et al. [98] studied rapeseed seeds, showing increased drought resistance due to oxidative stress responses and osmotic regulation. Susmita et al. [114] emphasize that cold plasma technology increases plant tolerance to drought, salinity, cold, and heavy metal exposure.

The physical etching effect of plasma helps seeds break dormancy and accelerates germination [81,99,113]. In addition, the chemical composition of the seed surface is changed, and the reactive species formed increase the availability of nutrients and reduce the pathogen load [82,85,100,104]. Mravlje et al. [115] note that plasma can reduce the dependence on chemical fungicides and reduce environmental toxicity.

Water-activated plasma (PAW) also has a significant effect on seed physiology. Chalise et al. [76] found that 3 min of direct plasma exposure increased wheat germination rate, while 15 min of PAW treatment increased productivity. In addition, with increasing treatment time, the seed contact angle decreased, and wettability increased, indicating improved surface properties and faster water uptake. These results are complemented by a study by Grainge et al. [71], which showed that GPAW promotes germination not only through physical changes, but also through molecular mechanisms—the interaction of reactive species with ABA and gibberellin metabolism, cell wall rearrangement, and endosperm weakening, simulating conditions favorable for germination.

So, plasma technology promotes the generation of reactive oxygen species (ROS), which activate physiological responses, enhance plant resistance to stress, and promote enzyme activity and nutrient uptake [25,99]. These technologies not only help reduce the microbial load on the seed surface [84] but can also reduce the dependence on chemical fertilizers and pesticides [83,101].

Despite their biological efficiency, some technologies, especially plasma, UV, or LEEB, may require higher energy inputs [116]. Therefore, it is important to assess energy availability and implement renewable solutions for sustainable implementation [117,118,119].

Despite the many advantages of physical seed treatment, some technologies, especially the use of cold plasma, low-energy electron beam (LEEB), and UV radiation, may be associated with higher electricity consumption. Waskow et al. [92] note that such methods, although effective in seed disinfection, may have limited applicability in regions where the availability or cost of electricity is a challenge. Therefore, it is important to assess energy costs and look for opportunities to reduce them for long-term sustainability. This encourages the search for solutions that include energy conservation and the integration of renewable sources such as solar energy [119]. Kabeyi and Olanrewaju [118] and Veit et al. [117] highlight that energy management strategies, including demand response and load scheduling, can contribute to more efficient energy use and cost reduction.

These physical seed treatment methods have a particularly positive environmental impact, as they reduce the reliance on chemical fertilizers and pesticides. Physical methods such as UV, plasma, or LEEB generate less dust during treatment [120], thus contributing to environmental safety. In addition, they help maintain beneficial microbial communities in the soil [51,121] and promote biodiversity [122].

In conclusion, physical seed treatment methods such as UV-C light, magnetic field, cold plasma, laser, and LEEB help to increase crop productivity and reduce the ecological footprint. They are a promising alternative to chemical treatments, with high biological efficacy and lower environmental pollution. However, it is important to further optimize the application parameters and evaluate the long-term effects, taking into account energy consumption and cost-effectiveness.

2.3. Biological Treatment and Environmental Impact

Biological seed treatment is increasingly being used as a sustainable and environmentally friendly alternative to chemical seed treatments in agriculture. This method involves the use of microorganisms (bacteria, fungi, algae) and biostimulants to improve plant health, germination, stress resistance, and reduce dependence on synthetic chemicals. Such biological solutions reduce the risk of chemical pollution and contribute to the preservation of soil microbiota.

The effect of biological treatment depends on the type of microorganisms used and the environmental conditions. Studies have shown that bacterial endophytes and rhizobacteria, such as Bacillus subtilis, Trichoderma harzianum, Azospirillum and Bradyrhizobium, etc., can improve seed germination, promote nitrogen fixation, improve nutrient availability, solubilize phosphorus, activate growth hormones, and enhance plant immunity [123,124,125,126]. For example, seed inoculation with Bacillus subtilis and Trichoderma harzianum improved root biomass and germination rate even under adverse conditions [127,128].

One of the most effective biological methods is biopriming, which involves soaking seeds in microbial-rich solutions. This process improves metabolism, increases stress tolerance, and promotes early growth [129,130]. Also effective are microbial consortia, i.e., combinations of several microbial species, which increase nutrient uptake, improve plant yield, and improve quality in various seed crops, such as chickpea, soybean, and sorghum [131,132]. Mycorrhizal fungi (especially arbuscular mycorrhizal fungi—AMF) are also effective components of biological treatment, as they improve phosphorus availability, stimulate symbiotic interactions, and enhance plant resistance to adverse conditions [133,134,135].

Biostimulants are natural or waste-derived substances that activate enzymes, stimulate the synthesis of phytohormones, and support plant metabolism. Such compounds are produced from agricultural, food, or paper industry waste [136,137,138], which contributes to the circular economy, reduces the need for chemical fertilizers, and at the same time maintains the soil microbiota balance [139,140].

Studies by Khasanov et al. [141] have shown that applying biological treatments at sowing can increase yields by 5–10%, while microbial inoculants improve the root system, nutrition, and plant resistance to drought and stress [142,143].

In addition to the agronomic benefits, biological treatments have significant positive environmental impacts. Inoculation helps maintain the diversity of soil microorganisms, increases soil biological activation, improves soil structure, and water retention [144,145,146]. In addition, carbon sequestration is promoted through the accumulation of organic matter and microbial biomass [147,148]. The use of microorganisms reduces the need for fertilizers, improves nitrogen fixation, and increases the efficiency of nutrient use. This reduces greenhouse gas emissions associated with fertilizer production [149,150]. This helps to mitigate the effects of climate change and, at the same time, contributes to the maintenance of sustainable ecosystems.

Despite the advantages, there are challenges. The effectiveness of microbes is limited by their short shelf life, sensitivity to storage conditions, and their competition with the local microbiota [28,51,151]. They can be washed out of the seeds or suppressed if not applied at the right time [152]. It is also important to consider soil properties, moisture, and temperature, which determine the success of inoculation [153,154].

The stability of the products, their short shelf life, and logistical constraints limit their use in commercial systems [155,156]. It is also necessary to ensure accurate dosage and contact with the seed—inaccurate application can reduce efficiency or even have negative effects [157,158]. Slower action and unpredictable results in some cases hinder their practical implementation in farms where a rapid effect is important [159,160,161,162].

In conclusion, biological seed treatments based on the use of beneficial microorganisms and biostimulants show great potential for improving crop productivity and ecosystem sustainability. They reduce dependence on chemicals, help maintain soil health, and can contribute to the development of resilient agricultural systems. Further research, stabilization of efficacy, and optimization of application strategies under different climatic conditions are necessary to ensure the success of these technologies.

In order to provide a concise summary of the discussed seed treatment technologies from a sustainability perspective,

Table 2. Comparison of the main seed treatment technologies in terms of efficiency, environmental safety, and application limitations.

Seed Treatment Method	Efficiency (Improving Germination, Killing Pathogens)	Environmental Impact	Environmental Impact	Notes
Chemical	+++ (very high)	* (high)	Residue accumulation: effects on soil and health	Provides high protection, but poses risks to ecosystems and human health due to chemical residues
Physical (UV, plasma, etc.)	++–+++ (high–very high)	** (low–medium)	Precise control of parameters is required; energy consumption	A sustainable and effective alternative, rapidly developing
Biological	++ (high, depends on the conditions)	*** (very low)	Stability of microorganisms; variability of effectiveness	A very sustainable technology, but its effectiveness depends on environmental conditions and the stability of microorganisms.

Note: +++—indicates very high efficiency of the technology; ++—high efficiency of the technology; *—indicates high environmental impact of the technology; **—low-medium environmental impact of the technology; ***—very low environmental impact of the technology.

is presented, which summarizes the effectiveness, environmental impact, and practical limitations of each method.

As can be seen from the table, physical and biological treatment methods show high potential to combine efficiency with environmental protection, while chemical treatment, although very effective, poses the greatest environmental challenge.

3. Principles of Ozonation, Mechanism of Action, and Effects on Seeds and Plants

Ozone is an important atmospheric oxidant that affects plants in a variety of ways, including photochemical reactions and gas exchange processes. To utilize ozone in agriculture and environmental management, it is essential to understand the principles of ozonation technologies, how ozone affects plants, and the effects of these interactions.

Ozonation is an advanced physicochemical process that uses ozone (O₃) as a strong oxidant for the disinfection and biostimulation of agricultural products. Due to the high redox potential of ozone (approximately 2.07 V), it can rapidly oxidize cellular components of microorganisms (bacteria, viruses, molds, fungi), such as lipids, proteins, and nucleic acids in microbial contaminants, thereby reducing the amount of pathogens on the surface of grains, and also disrupt their cell walls by oxidizing double bonds, sulfhydryl groups, polyunsaturated fatty acids, glycoproteins, and enzymes [163,164,165,166,167]. The mechanism of ozone formation and its interaction with bacterial and viral cells and subsequent decomposition into oxygen is presented in Figure 1.

Once the cell membrane is damaged, ozone can penetrate and interact with internal cellular structures, including nucleic acids, thereby destroying microorganisms. Unlike chemical disinfectants, ozone quickly decomposes into oxygen after the reaction and leaves no toxic by-products [168,169]. Viruses are oxidized through their protein coat, damaging the RNA structure, and molds through oxidative damage to the cell wall [170,171].

Electrical discharge methods, such as corona discharge and dielectric barrier discharge, are commonly used for ozone generation in agriculture [172]. These processes are based on the fact that under high energy exposure, such as ultraviolet radiation or electrical discharge, oxygen molecules (O₂) break down into radicals, which combine with other O₂ molecules to form ozone (O₃) [173,174,175]. These systems are designed to deliver controlled doses of ozone, either in gaseous form or dissolved in water (ozone water), for applications ranging from soil treatment to crop disinfection. Sujayasree et al. [176] also state that ozone can be used to treat agricultural products or seeds in gaseous form or in the form of ozonated water. The formation of reactive oxygen species (ROS) during the ozonation process is the main cause of these oxidative reactions, which deactivate seeds and reduce pest infestation in grain storage systems [177,178].

According to Yuan et al. [179], ozonation technologies are increasingly used due to their strong oxidative properties, which are applied in various fields, including wastewater treatment, food safety, and agricultural practices. Zhong et al. [180] indicate that the main principle of ozonation is the oxidative power of ozone, which allows the decomposition of complex organic compounds, inactivation of microbes, and improvement of product quality. In addition, Zapałowska et al. [181] emphasize that ozonation technologies primarily include the use of ozone as a disinfectant and preservative in various environments, while Piechowiak et al. [182] additionally emphasize that the effectiveness of ozone is influenced by concentration, exposure time, and environmental conditions. Granella et al. [183] also observe that the increase in the fungicidal effectiveness of ozone depends on temperature. Xue et al. [184] describe that ozone is a strong oxidant known for its ability to eliminate a wide range of microorganisms, including viruses, bacteria, and fungi. Pandiselvam et al. [185] emphasize that ozonation is a promising green technology due to its rapid degradation and absence of residues. Kim et al. [186] indicate that ozone is widely used in water treatment, food processing, and storage as a powerful disinfectant and oxidizing agent.

To assess the potential of ozone application, it is important to compare it with other seed treatment technologies, taking into account their operating principles, advantages, and limitations (

Table 3. Comparison of seed treatment technologies.

Technology	Operating Principle	Advantages	Disadvantages	Application Areas
Ozonation	O3 oxidation	No residues, effective, sustainable	Can damage sensitive seeds	Organic farming
Plasma	Electricity	Surface activation	Expensive equipment	High value-added seeds
UV radiation	DNA damage	Fast, no chemical residues	Limited penetration	Control of surface pathogens
Biological treatment	Inoculation of beneficial microorganisms	Improves microbiota, promotes growth	Effectiveness depends on the environment	Sustainable systems, organic farms
Chemical treatment	Fungicides, insecticides	Effective, standardized	Contaminants, resistance risk	Industrial seed production

).

As can be seen from Table 3, ozonation is distinguished by the fact that it effectively destroys pathogens without leaving chemical residues, but requires precise adjustment of parameters to avoid damaging seed viability. Meanwhile, the biological method is gentle but more sensitive to environmental conditions.

In summary, the principle of ozonation is that ozone reacts with microorganisms, oxidizing their cell walls and causing the death of the microorganisms. Ozonation can help reduce the spread of diseases and increase seed quality.

3.1. Possibilities of Using Ozone for Seed Treatment

Ozonation is increasingly being used as a sustainable seed disinfection method, with a strong oxidative effect without residual pollutants—allowing it to be integrated into organic agricultural practices.

Several studies have focused on the use of ozone during the pre-sowing and storage stages, demonstrating that controlled exposure can simultaneously disinfect and repair microdamage to seeds. Baskakov et al. [178] reported increased yield and quality of corn grains when seeds were ozonized during storage, while Baskakov et al. [187] highlighted that pre-sowing ozone treatment can effectively replace chemical pesticides, thereby reducing pesticide use.

Many experimental studies show that ozone can be effectively applied to treat various types of seeds, improving germination, reducing pathogen levels, and increasing yield.

Table 4. The effect of ozonation on various seeds.

Seed Species	Result	Ozone Dose	Time of Exposure	Forma	Reference
Corn grains	Ozonation (0.9874 mg/L, 138.6 min) reduced the prevalence of storage fungi—Aspergillus spp. by 78.5% and Penicillium spp. by 98.0%, confirming the fungicidal effect after 50 h of exposure.	2.14 mg/L, 5.8 L/min	0, 10, 20, 30, 50 h	Gaseous	[177]
Corn grain	Increased corn yield by 13.4% (9.3 c/ha), reduced immature cobs (−6.5%) and small fractions (−7.3%), increased cob number (+6.9%) and 1000-grain weight (+12.8%). Plants were 28.4% heavier, and grains were more uniform.	-	-	Gaseous	[178]
Corn seeds	Ozonation (12.5 g/m3, 5 min) ensured 100% germination within 2 days, improved seedling growth and germination under 100 mM salt stress, and reduced microflora to 5.31 log bacteria and 6.15 log yeast/mold.	12.5 g/m3	1–5 min	Gaseous	[188]
Corn seeds	Higher air flow (0.5–1.05 m3/min·t) accelerated ozone saturation and effectively inhibited A. flavus and S. zeamais. Low-temperature drying preserved grain color, but seed dressing is not recommended under such conditions.	2.30 mg/L	Air flows—0.50; 0.82; 1.05 m3/min·h	Gaseous	[189]
Corn seeds	The best seedling development indicators (germination rate, mass, length) were achieved at 0–30 mg/L ozone and 60–90 min soaking. Ozonation did not control Fusarium, while the fungicide provided 100% control.	0, 10, 20, 30 mg/L	0, 30, 60, 90, 120 min	Aqueous	[190]
Wheat seeds (cv IPR Catuara TM)	Fungal reduction 92.86% (1.87 → 0.13 CFU/g), did not affect germination and viability.	2000 mg/h. Air speed—0.5 ± 0.1 m/s.	45 min	Gaseous	[183]
Wheat (Triticum aestivum)	Ozonation during storage can improve seed germination, but too long or frequent exposure can have negative effects, so it is important to optimize the duration and frequency.	-	30, 60, 90, 120 min, cyclically, every 7, 14, 21 days	Gaseous	[191]
Spring wheat seeds	At the same ozone concentration, morphological indicators and disinfection changed similarly, but germination ability remained unchanged, and germination stimulation was not associated with disinfection efficiency.	1.5, 2.0, 3.5, 4.0, 25.0 g/m3, 1 L/min flow	0, 1, 2, 3, 4 h	Different ozone gases (moist air and dry oxygen)	[192]
Winter wheat	Ozonation increased the germination of winter wheat (“Ermak” +19.5%, “Victoria Odesskaya” +22%), the best results were achieved with a dose of 14.7 g·s/m3 and 14 days of storage. Optimal conditions: 14.0–17.0 g·s/m3 and 14 days before germination.	2.1, 8.4, 9.9, 10.5, 12.6, 14.7, 16.8, 18.9, 19.8 g·s/m3	0, 7, 14 days	Gaseous	[193]
Wheat, broccoli, alfalfa, and radish seeds	Reduced total phenolic content (TPC) in wheat (−39.4%) and sprouts (up to −47.7%), except for alfalfa, where TPC increased (+27.7%). Changes in sugar content depended on the species and duration of exposure.	50 ppm, 1 L/min	1–5 h	Gaseous	[194]
Wheat Barley Oat Corn seeds	Pre-sowing ozonation at an average concentration (≤5 mg/m3) should last ~38 min, and the optimal dose is ~95 min mg/m3 (for wheat 110–200, for barley 84–114, for oats 40–60, for corn 32–74 min mg/m3).	4.15–4.40 mg/m3 2.57–2.84 mg/m3 1.45–1.56 mg/m3 1.85–1.88 mg/m3	23–41 min 32–52 min 40–60 min 17–45 min	Gaseous	[187]
Barley seeds	Ozonation increased the diversity and amount of volatile organic compounds (VOCs), decreased alcohols and hydrocarbons, but increased aldehydes and acetic acid. Low doses of acetic acid promoted barley germination, while high doses inhibited it, revealing its role in germination regulation.	-	0, 10, 20, 40, 120, 240, 480, 960, 1440 min	Gaseous	[195]
Dii cultivar beetroot seed	Ozonation (0.1–120 mg/L, several minutes–hours) inhibited infections and increased germination and yield. For corn, 5–10 mg/L (up to 30 min) is most effective, for wheat—0.1–5 mg/L, as higher concentrations can inhibit germination.	0.5, 1, 3.5 mg/L 1 mg/L	10 min 5, 10, 20, 30 min	Gaseous	[196]
Soybean Seeds	Ozone reduced the prevalence of six fungi (including Phomopsis, Fusarium, Alternaria) without affecting germination, viability, conductivity, or enzymatic activity, and was safe for seed quality.	15, 25 g/m3	0, 20, 40, 60, 120 min	Gaseous	[197]
Soybean (Glycine max L.)	Germination improved after 4 months of ozonation, but decreased after 6 months due to oxidation. Ozone slowed the growth of moisture and free fatty acids, and vacuum packaging provided the best protection.	150 g/h	Pre-ozonate for 3 h. Then stored for 6 months, exposed to ozone for 3 h daily.	Gaseous	[198]
Pepper Seed	Trisodium phosphate completely eliminated the infectivity of pepper mild mottle virus (PMMoV) in pepper seeds, while ozonation was ineffective—the virus remained infectious except at a low concentration (0.01 mg/mL) after 14 h of ozonation. Neither method affected germination, but ozone is not suitable for standard PMMoV control.	20 ppm	14 h After treatment, the seeds were stored at 4 °C and 25% humidity.	Gaseous	[199]
Sunflower crops (Helianthus annuus L.)	60 min ozonation significantly reduced the prevalence of Alternaria, Fusarium, Aspergillus, and Penicillium without affecting seed germination, viability, and other physiological indicators.	1741 ppmv, 0.24 g/h	20, 60, 120 min	Gaseous	[200]
Sea Buckthorn (Hippophae rhamnoides L.)	Ozonation (100 ppm, 30 min) reduced water loss, bacteria (−3 log KFV/g), and yeast/mold (−1 log KFV/g), improving the quality and shelf life of the raw material.	10, 100 ppm	Treatment duration—10, 15, and 30 min at a gas flow rate of 4 m3/h at room temperature—20 °C.	Gaseous	[181]
Tomato seeds (S. lycopersicum ‘SC2121’), cucumber (C. sativus ‘Nefes’) seeds, tulip, daffodil, and hyacinth bulbs, wheat (‘Cumhuri-yet-75’ and ‘Gönen-98’)	Ozone and ozonated water effectively inactivated seed-borne pathogens (Fusarium, Clavibacter, Pseudomonas) without reducing germination. Better results were achieved by soaking the seeds, making the method promising for healthy propagating material.	100 L/h	-	Gaseous Aqueous	[6]
Spergula arvensis seeds	A 90 ppb ozone increased seed germination after storage and scarification, shortened the dormancy period, and improved survival in soil due to maternal effects, which may increase weed resistance and reduce crop productivity.	0, 90, 120 ppb	4 years	Gaseous	[201]
Grass seeds (Lolium multiflorum)	Plants produced 23% more seeds, but the endophyte reduced their viability, which was improved by ozone (0, 90, 120 ppb). Endophyte viability was significantly reduced only after 25 days of accelerated aging.	0, 90, 120 ppb	Ozone was applied for 5 days every 2 h.	Gaseous	[202]

summarizes the main results of the studies, indicating the nature of the effect, ozone concentrations used, exposure time, and medium.

As can be seen from the results presented in Table 4, the effect of ozone on different types of seeds depends on the dose, duration, shape, and treatment conditions—therefore it is necessary to select optimal parameters for each crop.

Studies by Golovin et al. [203] have provided strategies for optimizing ozone distribution and exposure time in grain stacks, ensuring that disinfection occurs without compromising the structural integrity of the seeds. Similarly, Shevchenko et al. [196] identified optimal moisture content and ozone dosage that preserve germination rates and improve seed quality, emphasizing the importance of precise control of treatment parameters.

The mechanism of action of ozone in seed treatment is multifaceted. In particular, its oxidative activity disrupts the cell membranes of bacteria and fungi, thereby inactivating these pathogens [166,177]. In addition to its disinfecting role, controlled ozonation modulates the biochemical composition of seeds. Avdeeva et al. [193] demonstrated that adequate doses of ozone improved the germination energy of winter wheat seeds, suggesting a hormetic effect where mild oxidative stress stimulates internal defenses and metabolic pathways. Bernate and Šabovics [204] reported a significant reduction in the number of enterobacteria in various seeds and seedlings, further confirming the antimicrobial efficacy of ozone treatment. In addition to direct seed disinfection, ozonation also affects subsequent seedling development, especially root and shoot viability. Bernate et al. [194] studies show that ozone exposure can induce changes in phenolic compounds and other bioactive metabolites during germination, potentially increasing seedling viability. However, both ozone concentration and exposure duration are critical parameters: too low a dose may be ineffective in killing pathogens, while too high a dose may damage seed viability. Therefore, it is necessary to precisely regulate ozonation conditions to maintain a balance between antimicrobial efficacy and physiological seed safety. Akdemir Evrendilek [188] and Shingala and Dabhi [191] found that controlled ozone treatment improved the viability and germination rate of corn and wheat seeds, respectively, and these results were directly related to better root development and early plant establishment. Dong et al. [205] also revealed that ozone treatment induces the release of volatile organic compounds (VOCs) from barley seeds, a response that may affect metabolic signaling during germination, while Dong et al. [195] demonstrated that optimal exposure duration not only improves seed quality but also ensures effective pest control.

Optimizing ozone treatment parameters is crucial to reap its benefits without damaging the seeds. Golovin et al. [203] and Shevchenko et al. [196] contributed to the elucidation of optimal ozone dosage regimens, ensuring that the beneficial effects on seed disinfection and viability are maximized while preventing oxidative damage. A comprehensive review by Sitoe [206] confirms the potential of ozonation as a residue-free, environmentally friendly alternative to conventional chemical treatments in grain preservation and processing. Furthermore, this method allows for a reduction in the use of chemical pesticides, as highlighted by Baskakov et al. [187] and Kyrpa et al. [207], thus supporting sustainable agricultural practices.

Ozone seed treatment has gained popularity due to its potential benefits [190], but ozone techniques also have some negative consequences, especially for oilseeds. One significant disadvantage of ozone treatment is its effect on the quality of oilseeds such as rapeseed and oilseed rape. It has been documented that ozone exposure can not only disrupt seed quality improvement but also cause degradation that can negatively affect oil yield [200]. Ozone exposure can disrupt the optimal levels of sulfur and nitrogen, which are crucial for seed quality, leading to reduced nutrient profiles in the seeds [208,209]. As a result, the oil extracted from these seeds may be of lower quality. Studies show that ozone interactions with these essential nutrients tend to exacerbate challenges associated with oilseed quality management, especially during critical growth stages [210].

Studies show that ozone treatment can inhibit the germination rate index of oilseeds, resulting in slower seedling development [195,200]. The resulting reduced seed viability further impairs the ability of planted seedlings to thrive, resulting in lower yields of higher quality oil [211], which is of particular concern to farmers seeking to maximize crop yield and quality [198]. Salisbury et al. [211] also note that detrimental morphological changes, such as reduced lipid content and altered composition, caused by oxidative damage from ozone cannot be ignored, as these factors have a significant impact on the food processing and oil extraction, as well as the quality of oilseeds. Studies show that ozone treatment can cause oxidation of essential fatty acids, which compromises the quality of the oil extracted from these seeds. One of the main mechanisms of this effect is lipid peroxidation—ozone oxidizes polyunsaturated fatty acids, which are key components of oil quality and nutritional value [192]. This process leads to fat instability, flavor deterioration, and loss of nutritional properties. Oxidative degradation caused by ozone exposure can produce harmful compounds that degrade the nutritional properties of the oil, thereby affecting its stability, flavor, and potential health benefits [192]. Furthermore, the use of ozone can alter the composition of the seeds—both qualitative and quantitative—which can reduce yield and viability after extraction [201].

It is also important to note the negative synergistic effects of simultaneous nutrient restriction (e.g., sulfur and nitrogen deficiency) and ozone treatment. The literature suggests that nutrient deficiency causes stress in these plants, which is further exacerbated by ozone exposure and hinders their overall development [202,212]. In the case of rapeseed, this dual stress not only reduces seed yield but also affects the essential amino acid content of the oil, thus reducing its nutritional value for feed and food [213]. In order to avoid harmful effects, it is recommended to apply lower ozone concentrations and shorter exposure times, especially for sensitive seeds such as oilseeds. Therefore, despite the obvious advantages of ozonation, it is necessary to accurately select the appropriate technological parameters for the seed type in order to avoid undesirable physiological effects.

3.2. Summary and Future Prospects

In summary, the principles of ozonation in the context of grain seed treatment involve the use of the strong oxidative properties of ozone to effectively disinfect seeds, improve their biochemical state, and promote vigorous seedling and root development. The mechanism of action is mainly determined by reactive oxygen species (ROS)-mediated oxidation, which not only neutralizes pathogenic organisms but also stimulates favorable metabolic processes in the seeds.

Ozonation, as a non-thermal treatment method, is distinguished by the fact that it does not leave chemical residues in the environment and food products, and the decomposition product of ozone is molecular oxygen. Due to this property, ozonation is in line with the principles of organic and sustainable agriculture, contributing to the objectives of the EU Green Deal, which aims to reduce the use of synthetic chemicals in agriculture and promote environmentally friendly technologies.

When applied under optimized conditions, ozonation becomes a promising technology for improving seed quality, crop establishment, and ensuring higher agricultural productivity while maintaining minimal impact on ecosystems. When applied under optimized conditions, ozonation becomes a promising technology for improving seed quality, crop establishment, and ensuring higher agricultural productivity while maintaining minimal impact on ecosystems. Due to its ability to destroy pathogens and modulate physiological processes, ozonation not only improves seed quality but also contributes to higher crop yields [6,197,199]. The success of ozonation depends on the correspondence of technological parameters to the biological properties of seeds; therefore, further optimization is necessary for specific species. Future studies should further deepen the determination of the optimal ozone dose and exposure duration ratio, in order to further increase the efficiency and safety of the technology under different environmental conditions.