INFLUENCE OF PRE-SOWING UV-RADIATION ON THE ENERGY OF GERMINATION CAPACITY AND GERMINATION ABILITY OF RAPESEED

The object of research is the rapeseed, which is the first among oilseeds by the volume of sowing. One of the most problematic places of the agricultural complex is an increase in the quantity and quality of the seed material. To solve this problem, scientists and agricultural specialists use various methods, preferring optical radiation – pre-sowing UV-seed treatment. Selection of treatment regimes requires detailed studies and a differentiated approach for each crop separately. In the work pre-sowing influence of ultraviolet UV-irradiation of rapeseeds on biological processes (germination energy, germination and growth) is investigated. 20 W low-pressure ultraviolet lamps of the type ZW20D15W (China) emitting in the C region are used. The radiation dose is measured according to standard methods using a Tenzor-31 radiometer (Ukraine). Samples of rapeseeds, in addition to control, are irradiated with ultraviolet radiation in the C region with doses of 10 J/m 2 , 20 J/m 2 , 50 J/m 2 , 80 J/m 2 , 100 J/m 2 , 120 J/m 2 and 200 J/m 2 . Irradiated and control samples of seeds are germinated in Petri dishes at an air temperature of 24 ± 2 ° C. The number of seedlings is counted after 3 days – the germination energy, and after 7 days – germination ability. Due to the use of UV irradiation at doses of 80-120 J/m 2 , the following results are obtained in comparison with the control sample: the germination energy of rapeseeds is increased by 20-26 %; germination ability increases by 16%. At the same time, the average biomass of plants from irradiated seeds increases by 18.3 % in comparison with the control samples for 10 days of growth. In field studies, the germination of rapeseeds after irradiation with a UV-C dose of 120 J/m 2 compared to the control sample increased by 16% and becomes 89 %.


Introduction
Rapeseed is a strategically important culture, as it occupies an important place in the food and energy balance of the state. Rapeseed oil, thanks to its unique biological properties, is widely used not only in the food industry, but in many branches of the economy [1][2][3].
Rapeseed has an important value as a valuable crop for the cultivation of green fodder for farm animals. The smell of green mass as a sideral fertilizer is equivalent to applying 15-30 tons per 1 ha of manure. Raising rapeseed improves the balance of rubber in crop rotation with most cereals. As a precursor of rapeseed, it is possible to reduce the costs of soil cultivation and plant protection products. Rapeseed is of great importance as honeyrapeseed flowers are attractive and easy to collect nectar, its flowering lasts from 25 to 30 days. This provides a large collection of honey -up to 90 kg per hectare, and sometimes much more.
Increasing the quantity and quality of crop production is the main task in the development of the agricultural complex. The central link in solving this problem is seed production. Seeds, the carrier of biological properties, determine decisively the quality and quantity of the crop. Scientists and agricultural specialists are constantly im-proving and developing new agro-activities and technical means for pre-sowing seed stimulation in order to improve their sowing quality [4][5][6]. Providing high crop yields at optimal costs and high-quality seed indicators, as well as mastering technologies for obtaining new types of rapeseed products, are important tasks for the agro-industrial complex for the near future.
One of the effective ways to improve the quality of the seed is influencing the seeds by physical factors: heating [7], the effect of ionizing gamma rays [8]. In agricultural practice, various methods of pre-sowing seed treatment are used -electrical [9] and magnetic fields [10] and electromagnetic radiation [11]. In [12], the influence of the degree of uneven heating of seeds in the electromagnetic field of ultrahigh frequency on their germination energy and germination was investigated.
Seed pre-sowing treatment using electrophysical methods was considered in [13,14]. Back in the mid-1980s, gas neon and helium lasers were used for pre-sowing seed treatment. Irradiation of barley seeds with red light at a wavelength of 754 nm causes an increase in productive bushiness by 37.2 % and a stalk length of 7 cm [15]. The amount of irradiation energy and the time of seed treatment are different for each culture, so the choice of treatment regime requires a differentiated approach [16].

ISSN 2226-3780
The use of UV irradiation is of great interest for stimulating growth and increasing the resistance of plants to external factors and increasing the yield of crops [17,18]. Investigation of the influence of pre-sowing irradiation of plant seeds with ultraviolet radiation on their growth, productivity, infection with fungal and other diseases has been initiated for a long time, but this problem has not been studied thoroughly enough, therefore, studies in this direction are topical.
In preseeding processing of seed material of agricultural enterprises of UV-irradiation cultures on biological processes, the effect is twofold: there is an increase or decrease in germination energy, germination and germination capacity.
Study of the influence of ultraviolet irradiation on the seeds of various crops in the pre-sowing processing, including rape, is actual.

The object of research and its technological audit
The object of research is the winter rapeseeds of the 2017. Rapeseed among the oilseeds of the cabbage family ranked first in oil content, as well as a valuable crop for the production of biofuels.
One of the most problematic places of the agricultural complex is an increase in the quantity and quality of the seed material. Rape seeds need an average of 3 to 10 days for germination, and at this time it is particularly sensitive to pathogenic microorganisms that are the causative agents of infections and diseases.
A great interest for raising seeds to external factors and stimulating growth and increasing yields is the treatment of seeds of crops with ultraviolet radiation. This allows to reduce the use of fungicides or even abandon them.

The aim and objectives of research
The aim of research is studying the pre-sowing effect of ultraviolet (UV) seed irradiation on biological processes (germination energy, germination and growth) in laboratory and field conditions. To achieve this aim, it is necessary to perform the following tasks: 1. Irradiate seeds with UV radiation in the area with artificial light sources.
2. Determine the necessary dose of pre-sowing seed treatment with UV irradiation in terms of: germination energy and seed germination.
3. Calculate the energy of germination ability and germination capacity of seeds. Compare the obtained results for irradiated samples with control samples.
4. Conduct comparative studies of plant biomass after 10 days and plant height after 12, 25 days of growth in field conditions for control samples with irradiated seed samples.

Research of existing solutions of the problem
Germination ability is the main indicator of seed quality [18]. For this purpose, the seed material is subjected to various means of action, where the leading role belongs to energy, activates the germination of seeds and strengthens the vital activity of the embryo at the initial stage [19].
As shown by the analysis of literature sources of existing methods of electromagnetic influence on seeds before sowing, UV irradiation is of the greatest interest [20][21][22]. Treatment of the pre-sowing material with bactericidal UV radiation in the C region not only increases the germination energy and seed germination [23], but also disinfects it [19].
The positive effect of pre-sowing seed treatment by UV radiation is noted in [23]: the germination energy and field germination of seeds are increased, which ensures stable yields of ornamental crops. It is shown in [24,25] that irradiation of UV-C seeds of wheat stimulated its germination. But, in spite of these studies, the question of determining the rational range of ultraviolet exposure in different energy areas and radiation doses, of different crops, including rape, continues to be undefined.
Pre-sowing UV irradiation of seeds creates a complex of effects -increasing the energy of germination ability and germination capacity [26,27]. It also stimulates growth processes, increases the stress tolerance of plants [22] and disinfects seeds from pathogens [24]. This allows to reduce the use of pesticides, reduces the concentration of pesticides in the soil and improves the quality of crop production and its yield [28].
Thus, the results of the analysis make it possible to assert that the most important effect that UV irradiation creates upon pre-sowing treatment is an increase in the energy of germination ability and germination capacity [26,27,29].

Methods of research
The germination ability energy and seed germination capacity are carried out in laboratory conditions according to the methods according to [30]. These values are compared for seeds irradiated with different doses of UV-C with control samples (without irradiation). By germination energy is meant the percentage of sprouted seeds in 72 hours, and the germination of seeds is the percentage of germinated seeds in 7 days.
Samples for the study are selected from the consignment of rapeseed in accordance with the requirements of [30].
Pre-collected seed samples are tested for CP4 EPSPS protein, the presence of which indicates a gene modification of the rape variety. The test set AgraStrip RUR-HS from ROMER Labs (Austria) is used for testing [31]. The analysis is carried out in accordance with the GAFTA 124 Grain and Feed Trade Association standard [32].
200 seeds for a control sample and 200 seeds for irradiation with different doses of UV-C are passed for the experiments.
The seeds are laid out on several layers of moistened filter paper in Petri dishes and kept in a thermostat at a temperature of 7± 2 °C for 1 day. Further cooled samples (except control ones) are irradiated with UV-C doses of 10 J/m 2 , 20 J/m 2 , 50 J/m 2 , 80 J/m 2 , 100 J/m 2 , 120 J/m 2 and 200 J/m 2 .
For exposure, a low-pressure UV lamp of the type ZW20D15W (China) with a power of 20 W is used [33]. The distance from the lamp to the seed samples is 0.25 m. The UV-C radiation is measured using a Tenzor-31 (Ukraine) radiometer using the procedure [34].
Irradiated and control samples of the seeds are germinated in Petri dishes at an air temperature of 24±2 °C. The first appearance of seedlings (energy of germination) is carried out after 3 days, and the germination rate after 7 days. TECHNOLOGY AUDIT AND PRODUCTION RESERVES -№ 5/1(43), 2018 ISSN 2226-3780

Research results
In laboratory conditions, studies are carried out on growing plants after UV irradiation with a dose of 120 J/m 2 in a special soil -the «universal» substrate [35], which includes all the necessary macro-and microelements. The air temperature in the room is kept within 24-26 °C with a relative humidity of 60-75 %. The growth cycle to the control measurement is 10 days.
In addition to laboratory studies, field studies of the similarity of the same lot of rapeseed and its growth in the first days of development in the conditions of open ground are conducted. The similarity of irradiated seeds with a dose of 120 J/m 2 and the biomass of the terrestrial part was compared with the control unirradiated sample.
The research results are shown in Fig. 1 and are summarized in Tables 1, 2.   The results of analysis of the rapeseed sample, according to [32], show the absence of the CP4 EPSPS protein, indicating a rape variety that is not genetically modified.
Research results of rapeseed germination energy as a function of the dose of UV-C irradiation (Fig. 1) show that at doses of 80-100 J/m 2 , the germination energy increases by 20÷26 % in comparison with the control sample, and the similarity by 16 %. In this case, the average biomass of plants from irradiated seeds increases by 18.3 % in comparison with the control sample for 10 days of growth (Table 2).
In field studies, the germination of rape seeds after irradiation with a UV-C dose of 120 J/m 2 compared to the control sample increased by 16 % and becomes 89 %. The height of plants from irradiated seeds on the 12th day of growth exceeded control samples by 7 %, and by day 25 -by 5 %. Moreover, the height of the ground portion of plants from irradiated seeds on day 12 is 13 % (at 29 % for the control sample), and on day 25, respectively, 8 % and 16 %.

SWOT analysis of research results
Strengths. Studies have shown that UV irradiation in doses of 80-120 J/m 2 positively affects the most important indicators of seed material: germination ability and germination energy, since the increase in these values is 16-20 %.
In the field, there is a positive UV effect on the development of the terrestrial part, since the irradiated seeds germinate faster. And in the future, with its growth after 10 days and after 25 days, the average value of the length of the ground part of plants exceeds the height of the control unirradiated samples by 5-7 %.
The effectiveness of ultraviolet irradiation of seeds in comparison with other methods of stimulation of growth processes is low energy consumption: the cost of electricity amounted to 0.0005 kW per 1 kg of seed. The processing time for the samples is 60 s when irradiated with a dose of 120 J/m 2 .
The cost of the pilot installation for the work is 35.5 USD. The design of the installation takes into account modern technical solutions for the development of such devices: -electrical circuit with electronic starting equipment; -a non-zoned ultraviolet lamp with a high efficiency in the UV region -30 % of the rated power. Lamps of this type are successfully used for bactericidal disinfection of drinking water [36] and air [37]. Pre-sowing treatme nt of seeds UV-C can find practical use in growing plants without the use of chemicals, growth stimulants. This is a promising area in the field of agriculture, since it makes it possible to reduce the amount of fungicides in the pre-sowing treatment or to abandon them altogether.
Weaknesses. One of the negative aspects of pre-sowing UV irradiation of seed material is that it is necessary to take into account the safety requirements: protection against direct and reflected ultraviolet rays from entering the personnel and others.
Opportunities. In the future, it is planned to conduct research on irradiation of seeds with UV radiation in other energy regions B and A. This will make it possible to compare plant growth parameters in various regions of the ultraviolet spectrum and to carry out calculations of the necessary costs in each experiment.
Threats. Additional costs are required for pre-sowing plant stimulation with UV irradiation, but they are compensated for by increasing the yield and reducing the number of chemicals used in the pre-sowing treatment.

Conclusions
1. Low-pressure ultraviolet lamps with a range of ultraviolet radiation of 200-280 nm are used for pre-sowing irradiation of rapeseeds.