UDC:581:53

INFLUENCE OF TREATMENT OF CORN SEEDS OF THE "DILSHOD" VARIETY WITH A BARRIER DISCHARGE ON THEIR GERMINATION, PLANT GROWTH AND PRODUCTIVITY

Nazirov F.M, Khojazoda T.A.

Tajik National University

Introduction. Barrier discharges (BD), in which the current is limited by at least one dielectric layer, and the characteristic dimensions of the electrodes significantly exceed the interelectrode gap, are effective technologies for generating nonequilibrium plasma in gases at atmospheric pressure. The unique properties of barrier discharges determine their wide application in various technological processes, including ozone generation, surface modification, coating, pollution control, sterilization and disinfection, CO2 lasers, excimer lamps and plasma display panels (PDP). Intensive research into the properties of barrier discharges is closely related to their industrial application. Devices and installations using barrier discharges are constantly being improved in order to improve the characteristics of the corresponding process or device.

A barrier discharge is a fast-flowing gas discharge, the duration of the current pulse (tens of nanoseconds) in which is limited by the surface charge deposited on the dielectric surface. Typically, the length of the discharge gap varies from several tens of micrometers to several millimeters. Depending on the properties of gases, operating parameters and boundary conditions, discharges can manifest themselves as microdischarges, organized discharge structures or have a diffuse nature. In filamentary discharges, the radius of the conductive channels is approximately 0.01 to 0.1 cm. A discharge where the current passes through one or more dielectric layers, and the dimensions of the electrodes significantly exceed the interelectrode distance, is called a barrier discharge. Characteristic features of barrier discharge plasma include high pressure (hundreds of Torr or more), spatial inhomogeneity and short duration of various physical and chemical processes. Typically, in addition to the volume discharge, randomly located microdischarges (filaments) are observed in barrier discharge plasma, the current duration in which is from 10 to 50 ns. Barrier discharge plasma is a highly nonequilibrium system, where the average electron temperature can reach several electron volts, while the gas temperature remains close to the temperature of the dielectric barriers. Barrier discharges are effective technologies for creating nonequilibrium plasma in gases at atmospheric pressure.

As already mentioned, the properties of barrier discharge have led to a wide range of industrial applications, including ozone generation, surface modification, coating, pollution control, sterilization and disinfection, CO2 lasers, excimer lamps and plasma displays.

 

 

 

 

 

 

 

 

 

 

Fig. 1 The configuration of a barrier discharge with two dielectric layers is shown.

Intensive research into the properties of barrier discharges is driven by their industrial applications. A detailed review of the history of barrier discharges, their properties, and industrial applications can be found in the scientific literature. In recent decades, interest in the study of barrier discharge properties has increased due to its widespread use in excimer lamps and, especially, in plasma display panels. Depending on differences in gas properties, operating parameters, and conditions, discharges in barrier discharges can take the form of microdischarge trains and self-organization [1].

Dielectric barrier discharge (DBD) is a form of gas discharge in which the electrodes are isolated from the plasma by dielectric materials. In such a discharge, the electrons have high energy (4-5 eV), and the gas temperature approaches the temperature of the electrodes. Research on (DBD) began in the 19^th century, with the work of W. Siemens on ozone generation. This type of discharge is also often called a «silent discharge»[2].

The effect of pre-sowing treatment of seeds with barrier discharge plasma on the morphogenesis and productivity of Eruca sativa Mill. plants remains insufficiently studied. In our study, we analyzed the effect of such seed treatment on the growth and development of Eruca sativa Mill. The object of the study was arugula seeds of the 'Dikovina' variety. Untreated seeds were used as a control. The experimental seeds were treated with barrier discharge plasma for different time intervals (5, 10, 15 and 20 seconds). We used a plasma-chemical reactor with a planar arrangement of electrodes and a dielectric barrier made of glass fiber for seed treatment. The parameters of the discharge gap, the amplitude of high-voltage voltage pulses and the repetition frequency were determined. Our studies were carried out in a photoculture under certain conditions of illumination, temperature and air humidity. Seed germination and plant development were monitored by measuring morphometric parameters and the content of photosynthetic pigments in the leaves[3].

Agricultural development is inextricably linked with increasing crop yields, which stimulates active efforts to improve agricultural practices. A key factor in this process is improving seed production.

Seeds play a crucial role in determining the biological and economic characteristics of plants that affect the quality and quantity of the harvest. State standards regulate the requirements for seeds imposed on agricultural enterprises.

Seed production includes a number of technological stages, such as post-harvest storage, pre-sowing treatment, disinfection and sowing. At each stage of seed production and storage, they can be exposed to adverse climatic and economic factors, which can lead to deterioration in their quality.

Under unfavorable storage or growing conditions, seeds can lose germination, become vulnerable to diseases, be attacked by insect pests and receive mechanical damage. Agricultural experts and scientists are actively studying methods and strategies to improve seed germination. In recent years, electrotechnological methods have been introduced into agriculture to stimulate the growth of grains and vegetables [4].

The main focus in agriculture should be on improving the sowing characteristics of seeds of various crops using modern technologies. Improving seed quality plays a key role as it directly affects crop yields and, consequently, food production. Seed quality depends on factors such as nutrient availability, storage and growing conditions, use of growth promoters, and fertilization methods. However, problems associated with diseases and pathogens arise during the storage and growing of plants. Although chemical treatment can effectively combat pathogens, it can lead to the accumulation of harmful residues in seeds, which poses a threat to human health. An effective solution to these problems is pre-sowing seed treatment using physical methods to improve germination and other sowing characteristics.

Several physical methods have been developed for pre-sowing seed stimulation, including thermal treatment, laser and ultraviolet irradiation, magnetic and electric fields, and ionizing radiation. Plasma and electron beam treatment methods are known to show promising results. Artificial plasma, which imitates sunlight, improves seed germination and extends shelf life by inhibiting microbial growth. Irradiation doses effectively destroy bacteria and pathogens, disinfecting seeds and preserving water and nutrients. These methods represent significant advances in agricultural technology and promise to improve seed quality and increase crop yields [5].

The purpose of pre-sowing treatment of corn seeds by physical methods is to stimulate biophysical processes, promote adaptation to adverse environmental conditions and protect plants from diseases. These methods, based on the principles of bioregulation of natural plants, are aimed at increasing the productivity of agricultural crops. Pre-sowing seed treatment with an ultra-high-frequency electromagnetic field (UHF EMF) can be effectively used as a method of pre-sowing seed preparation. The effect of high-energy millimeter-range electromagnetic field radiation on the post-germination of corn seeds can affect the initial stages of ontogenesis. The effectiveness of such physical impact on growth processes in the roots and sprouts of corn depends on the frequency parameters, power and time of treatment. Plant growth and development at this stage are regulated by common metabolites and phytohormones. Seeds and sprouts are the most vulnerable stages of the plant life cycle.

During germination, reserve substances are activated and converted into new compounds necessary for initial growth. Transitions between different stages of plant development are accompanied by biophysical changes in the composition and content of intermediate metabolites, which can change significantly under the influence of an electromagnetic field.

To assess germination, laboratory experiments were conducted in accordance with GOST 12038-84 in triplicate. Seeds not treated with microwave EMF were used as a control. During the experiments, the effect of pre-sowing exposure to an electromagnetic field on the length of roots and the first shoots of corn on the 7th day was assessed.

One of the main problems in plant growing is that sown seeds do not always fully realize the genetic potential of agricultural crop productivity. Therefore, it is extremely important to focus on improving the methods for assessing the quality of seeds before sowing. Seed quality is a set of physiological and biochemical indicators that can change significantly under the influence of environmental conditions while maintaining the genotype of the variety. The genetic component of quality is determined by the purity of the variety and is the basis for the realization of its potential productivity. High-quality seeds provide the starting potential for the formation of an optimal agrophytocenosis.

Seeds, as a material for propagation, are characterized by sowing qualities, a set of properties that determine their suitability for sowing and storage. According to GOSTs, the sowing qualities of seeds are assessed by such indicators as varietal purity, contamination and contamination of seeds, contamination with pathogens, viability, germination energy and germination.

Seed viability is one of the most important indicators of their quality. This indicator is assessed by various methods, including tetrazole topography, indigo carmine and acid fuchsin staining, and the luminescent staining method. [6]

The use of non-thermal plasma for environmental cleaning shows promising results due to the chemical properties of active substances formed in the plasma. This plasma is characterized by high electron energy and low temperature, which makes it effective for disinfection and sterilization of surfaces. Gliding electric discharge (glidarc) is a simple and economical method of producing non-thermal plasma at atmospheric pressure. It is carried out between moving electrodes using high voltage. The gas flow is directed along the axis of the electrodes, which allows the arc to slide, and the temperature of the ionized gas is reduced to the level of non-thermal plasma. Chemical reactions in glidarc plasma include the formation of NO0 and HO0 radicals, which promote oxidation processes. These radicals in turn can initiate the formation of other active forms of oxygen and nitrogen [7].

In recent years, low-temperature plasma has been widely used in agricultural machinery. Studies have shown that the products of volumetric and surface barrier discharge (VBD) plasma have a positive effect on the seeds of cultivated plants, especially on the seeds of various cereal varieties. Plasma treatment (VBD) is able to change the water status of naked seeds, improve their wettability, change the surface structure (including the formation of microdamage and micropores), and significantly reduce the phytopathogenic load on germinating seeds.

The purpose of this study is to clarify the role of long-lived chemical compounds formed when using VBD (surface barrier discharge) plasma in the process of modulating the germination of grain crop seeds. To minimize the influence of various factors on the seeds, they were placed relative to the plasma-electrode system of the SBD. The study used seeds of soft winter wheat (Irkutskaya variety, 2017 harvest), soft spring wheat (Novosibirskaya-29 variety, 2015 harvest), winter triticale (sample 430-6002, 2016 harvest) and winter rye (Chulpan variety, 2014 harvest). The seeds were germinated for three to six days in four replicates of 50 seeds per variant on one layer of filter paper pre-moistened with distilled water, in the dark at a constant temperature of 24°C. Upon completion of the experiment, the number of germinated seeds, the shoot length of individual seedlings and the length of each root were measured. Statistical data processing was performed using a programming language, and the reliability of differences between variants was confirmed using Tukey's multiple comparison test. The study was conducted using the collections of the Bioresource Center and the Bioanalytics Center of the Siberian Institute of Plant Physiology and Biochemistry of the Siberian Branch of the Russian Academy of Sciences in Irkutsk [8].

The results of the study show that the treatment of wheat seeds with LPBD (Dielectric Barrier Discharge) plasma significantly improved their germination, as well as plant growth and development.

The average seed germination increased significantly after plasma treatment for 3, 6, 9 and 12 minutes compared to the control group. The highest germination was achieved after 6 minutes of treatment.

The seed treatment also increased the average root and shoot length, as well as the fresh and dry weight of plants. The highest values ​​of root and shoot length, as well as dry weight of plants were achieved after treatment for 6 and 9 minutes.

The average chlorophyll level, number of shoots, number of stems, stem diameter, plant height, leaf blade length, leaf blade diameter also increased after plasma seed treatment. The highest chlorophyll level and the maximum number of shoots were achieved after 6 minutes of treatment. The average panicle length and average panicle diameter also increased after plasma treatment. The maximum average number of grains per panicle was achieved after 6 minutes of treatment.

The average thousand grain weight and average yield also increased after plasma seed treatment. The maximum yield per square meter was achieved after 9 minutes of treatment.

Thus, LPDBD plasma treatment of wheat seeds has a positive effect on their germination and contributes to improved plant growth and development, which can lead to increased yields [9].

It is evident that agriculture plays a key role in Nepal’s economy, providing livelihoods for a large portion of the population while accounting for a significant portion of the land area. However, like many other countries, domestic production cannot always meet the demand for food, making the country dependent on imports.

Interestingly, Nepal is making use of its resources such as mustard seeds, which are not only an important source of nutrients but also have potential medicinal properties. This may represent significant potential for the development of agriculture and pharmaceutical industries in the country.

It is also important to note that traditional farming practices may not provide sufficient surplus to meet all demands, so upgrading and adopting new practices may be an important step to improve farmers’ livelihoods and ensure food security in the country.[10]

The use of LTP for seed treatment can positively impact plant germination and growth. This seed treatment method has a resource-efficient impact by increasing germination percentage, accelerating seedling growth and development, and reducing microbial load in seeds. In addition, LTP treatment helps maintain normal physiological and metabolic activity in plants, which may be particularly important under drought stress conditions. Research shows that LTP can alter seed structure, increasing moisture penetration and seed absorptive capacity, which promotes germination under drought conditions. This opens up prospects for the application of LTP in agriculture to increase crop yields and promote sustainability of agricultural production [11].

This study shows that the use of non-thermal plasma, especially dielectric barrier discharge (DBD), can be an effective way to improve rice seed quality and increase crop yield. Plasma seed treatment improves hydration, hygroscopicity, and moisture content in seeds. This affects the quality of seedlings, promotes better seed germination, and prolongs their shelf life. The study found that plasma seed treatment increased seed water absorption, accelerated germination, and enhanced root growth. Plasma-treated seeds had higher viability and produced 10% longer seedlings than untreated seeds. DBD plasma can modify seed coats at the nanoscale, which promotes more efficient seed impregnation and improves seed viability. In addition, it is useful for long-term seed preservation.

Thus, plasma seed treatment can be an important tool in agriculture to increase crop yield and improve crop quality [12].

Experimental part

The study was carried out on the seeds of the Dilshod variety of corn. Preliminary treatment of the seeds with a barrier discharge was carried out in 2023 in the laboratory of the Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences (IHCE SB RAS) for 2, 4 and 6 minutes. A 10 ml glass cuvette served as a source of barrier discharge at atmospheric pressure. The electrodes of the discharge system had a coaxial design: the main electrode was multi-pointed and immersed in the cavity of the cuvette, and the outer electrode had a cylindrical shape and covered the outer surface of the cuvette.

The pulse frequency was 71 kHz, and the duration of the current pulses was approximately 1 μs, the current amplitude was about 12 mA, and the voltage amplitude was approximately 290 V.

The equipment used for seed treatment included the following components:

Gas supply tube: A gas source required to maintain atmospheric pressure in the cuvette.

Glass cell: The container in which the barrier discharge takes place. The cell walls serve as a dielectric barrier separating the electrodes of the discharge system.

External electrode: The electrode located outside the glass cuvette and providing contact with the external environment.

Internal multipoint electrode: The electrode is placed inside the cuvette. It usually has a polygonal base to ensure uniform distribution of the discharge plasma.

Results

Overall germination in the group with seed treatment with barrier discharge for 2 minutes with cooling for 48 hours increased from 273 to 278, and in the group with treatment for 4 minutes - up to 293. This may indicate a positive effect of barrier discharge treatment on the ability of seeds to germinate. Plant height after seed treatment for 2 minutes and 4 minutes with cooling for 48 hours increased compared to the control group. This may indicate stimulation of plant growth due to seed treatment. Seeds treated with barrier discharge for 4 minutes show the highest number of ears per shoot - 2.5. This is a significant increase compared to the control group, where this value is 1.2. This may indicate more intense formation of ears after seed treatment.

Fig.2 Effect of barrier discharge with cooling for 48 hours on corn yield

 

The most significant increase in yield is observed in the group with 4-minute seed treatment - from 17 t to 48.7 t per hectare. This indicates a significant increase in the productivity of corn crops with this seed treatment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Barrier discharge with cooling for 48 hours
	Date of processing	Date of sowing	Date of harvesting	Amount sown	Area sown (Hа)	Total germination 10-day	Height of plant. (cm)	Number of cobs per growth. (pcs.)	No. of cobs on all plants. (pcs.)	Yield
										Weight of grains per cob. (Kg)	Масса  урожайности. (Кг)	Масса с 1 га.  (т)
Cont	01.03.2023	03.03.2023	21.06.2023	300	0.004615	273	189	1,3	354,9	0,2877	102,1	22,1
Rev. 2 min				300	0.004615	278	206	1,6	444,8	0,2767	123,1	26,7
Cont				300	0.004615	271	218	1,5	406,5	0,2841	115,5	25,0
Rev. 4 min				300	0.004615	293	233	2,5	732,5	0,3073	225,1	48.7
Cont				300	0.004615	262	202	1,2	314,4	0,249	78,3	17,0
Rev. 6 min				300	0.004615	279	231	1,6	446,4	0,243	108	23.4

Table 1. Effect of barrier discharge with 48-hour cooling on growth and yield of corn

 

An increase in the overall germination is observed in the group with seed treatment with a barrier discharge for 2 minutes followed by cooling for 72 hours from 284 to 289, and in the group with treatment for 4 minutes - to 296. This indicates a possible positive effect of barrier discharge treatment on the ability of seeds to germinate. The growth rate of plants after seed treatment for 2 and 4 minutes with cooling for 72 hours also increases compared to the control group, which may indicate stimulation of plant growth due to seed treatment. Seeds treated with a barrier discharge for 4 minutes exhibit the highest number of ears per plant - 2.7. This is a significant increase compared to the control group, where this value is 1. This may indicate more intense formation of ears after seed treatment.

Fig.3 Effect of barrier discharge with cooling for 72 hours on corn yield

 

The most significant increase in yield was observed in the group with 4-minute seed treatment - from 14.8 tons to 53.2 tons per hectare.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Barrier discharge with cooling for 72 hours
	Date of processing	Date of sowing	Date of harvesting	Amount sown	Area sown (Hа)	Total germination 10-day	Height of plant. (cm)	Number of cobs per growth. (pcs.)	No. of cobs on all plants. (pcs.)	Yield
										Weight of grains per cob. (Kg)	Weight of yield. (Kg)	Weight from 1 ha. (t)
Cont	01.03.2023	04.03.2023	21,06,2023	300	0.004615	284	197	1,7	482,8	0,2877	138,9	30,1
Rev. 2 min				300	0.004615	289	243	1,7	491,3	0,2767	135,9	29,5
				300	0.004615	264	208	1,8	475,2	0,2841	135,0	29,3
Cont Rev. 4 min				300	0.004615	296	260	2,7	799,2	0,3073	245,6	53,2
				300	0.004615	274	213	1	274	0,249	68,2	14,8
Cont				300	0.004615	285	230	1,3	370,5	0,243	90	19,5

 

Table 2. Effect of barrier discharge with 72-hour cooling on growth and yield of corn

This indicates a significant increase in the productivity of corn crops with this seed treatment.

Conclusion. Based on the obtained results of the study, it can be concluded that the treatment of corn seeds with a barrier discharge has a significant positive effect on their ability to germinate and further plant development. Firstly, the treatment of seeds with a barrier discharge leads to an increase in germination. Already after 48 hours of cooling, an increase in seed germination is noted, and this effect is maintained even with a longer cooling period of 72 hours. This is an important indicator of the effectiveness of this treatment method.

Secondly, stimulation of plant growth is observed after seed treatment with a barrier discharge. An increase in plant height and the number of cobs on one plant indicate more active plant development after treatment.

Finally, the most important result is a significant increase in yield in the group with seed treatment for 4 minutes with cooling for 72 hours. This indicates a potential prospect for using seed treatment with a barrier discharge to increase the productivity of corn crops. Thus, our studies confirm the effectiveness and prospects of using barrier discharge in agriculture to improve the germination, growth and yield of corn. Further studies can be aimed at optimizing the parameters of seed treatment and a deeper understanding of the mechanisms of its action.

 

REVIEWER: Sattorov R.B.

Doctor of Biological Sciences, Professor

REFERENCES

1. Pushkina, N. V., Pre-sowing treatment of corn seeds with an electromagnetic field of the microwave range the effect of resonant frequencies on growth processes and their regulation in roots and seedlings. / N. V. Pushkina, P. Kurchenko // - 2016 Proceedings of BSU, volume 11, part 2. – Рр.1-2.
2. Avtaeva, S. V. Barrier discharge: Research and application. / S. V. Avtaeva // 3-5 2016.
3. Matyunin, A.N. Research of ozone generation systems in a barrier discharge with high-intelligence electrodes. – Рр.20.
4. Minich, A.S. The effect of pre-sowing treatment of seeds with barrier discharge plasma on the productivity of ERUCA SATIVA, / I. B. Minich., A.E. Ivanitsky., I.D. Ivanova., S.V. Kudryashov., A.N. Queue., A. Yu. // Ryabov. 2018. – Рр.
5. Kacheishvili, S.V. Azov-Black Sea State Agroengineering Academy / Zernograd – 2000. – Р.13.
6. Isemberlinova, A.A. Investigation of the effect of beam-plasma treatment on the sowing qualities of seeds / A.A. Isemberlinova // Tomsk, 2016. – Pр. 8-23.
7. Alekseychuk, G.N. The growth force of grain seeds and its assessment by the accelerated aging method / G.N. Alekseychuk // 2009. – Pр.3-25.
8. Kamse-Mogo J.-P. Processing of corn seeds with non-thermal plasma generated by a sliding electric discharge for use in agriculture. / J. Kamgang-Yubi, S.A. Dzhepang, B.S. Tamo // 1971. Volume 49, Issue 8. – Рр. 8-16.
9. Lazukin A.V. The effect of plasma products of a surface barrier discharge on the germination of cereals / A.V. Lazukin // 2020. – Pр.8-20.
10. Hassan, M. The effect of low-pressure dielectric barrier discharge plasma (LP DBD) on increasing germination, growth and nutritional properties of wheat, / M. Hassan, S.S. Rahman, S.A. Sajib, M.F. // Hossein. 2021. – Рр.5-7.
11. Guragain, R.P. Increasing the germination of mustard seeds (Brassica nigra) using a dielectric barrier discharge (DBR), / H.B. Baniya., B. Shrestha., D.P Gurageyn // -2012. – Рр.6-13.
12. Rongsangchaycharyan, T. The effect of dielectric barrier discharge plasma on the hydration and hygroscopicity of rice seeds (Oryza sativa L.) / K. , D. Onvimol., N. Tefiruk // 2020. – Pр.4-13.

 

INFLUENCE OF TREATMENT OF CORN SEEDS OF THE "DILSHOD" VARIETY WITH BARRIER DISCHARGE ON THEIR GERMINATION, PLANT GROWTH AND YIELD PRODUCTIVITY

The aim of the study is to evaluate the effect of barrier discharge treatment of corn seeds on their germination, plant growth and yield. Three groups of seeds were treated for 2, 4 and 6 minutes, followed by cooling for 48 and 72 hrs, respectively. The results showed significant increase in germination, plant height and number of cobs after seed treatment, especially in the treatment for 4 minutes followed by cooling for 72 hours. The highest increase in yield was recorded in the same group. The data obtained indicate the promising use of barrier discharge seed treatment to increase the productivity of corn crops.

Key words: corn, seed, treatment, barrier discharge, germination, plant growth, yield.

Information about the authors:  Nazirov Firdavs Mirzorakhmatulloevich - Tajik National University, Doctoral Ph.D, Department of Physical Electronics. Address: 734025, Dushanbe, Tajikistan, Rudaki Ave., 17. Phone:  +992905090901. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Khojazoda Toir Abdullo - Tajik National University, Doctor of Physical and Mathematical Sciences, Professor of the Department of Physical Electronics. Address: 734025, Dushanbe, Tajikistan, Rudaki Ave., 17. Phone:  +992900526352.  E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Article received 16.02.2024

Approved after review 01.10.2024

Accepted for publication 09.10.2024