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The aim of the paper was to examine the allelopathic influence of aqueous extracts of herbs and medicinal plants on the quality parameters of aged soybean seeds. The research was carried out at the Institute of Field and Vegetable Crops in Novi Sad on aged seeds of two soybean varieties, NS simba and NS viseris. The seeds were aged for 20 months. In order to determine the allelopathic effect, the seeds were primed in aqueous plant extracts: geranium (Geranium sinense), dill (Anethum graveolens), andy everlasting (Helichrysum arenarium), creeping thyme (Thymus serpyllum), celery (Apium graveolens), oregano (Origanum vulgare), basil (Ocimum basilicum), lemon balm (Melissa officinalis), rosemary (Rosmarinus officinalis), wormwood (Artemisia absinthium), peppermint (Mentha x piperita), sage (Salvia officinalis), and lavender (Lavandula angustifolia). The results show that it is not possible to talk about the universal application of a particular aqueous extract, because the effect of the allochemicals was significantly influenced by the variety. In the variety NS viseris, all aqueous extracts except Melissa officinalis, significantly reduced GE, GP, and VI. The most negative effect was achieved with the use of Apium graveolens, Thymus serpyllum, and Ocimum basilicum. Apium graveolens and Thymus serpyllum also had the greatest impact on quality reduction in the NS simba variety. However, in the NS simba variety, a significant increase in seed quality was achieved in addition to the reduction. The use of the aqueous extract of Salvia officinalis increased GE and GP by 13.7%, and VI by 10.21%. A positive effect was achieved with the use of Melissa officinalis. All aqueous extracts had a significant effect on T50 in both varieties, even the aqueous extracts that had a negative effect on GE and GP.

The aim of this study was to investigate the influence of aqueous extracts of different plant species on the grain and protein yield of soybean. The testing was conducted at the Institute of Field and Vegetable Crops in Novi Sad on the seeds of the NS Apolo variety. The aqueous extracts of the above-ground part of nettle, the above-ground part of nettle and comfrey, whole banana fruit, banana peel, onion bulbs leaves, the top parts of willow twigs and the top parts of soybean plants were foliarly applied. In addition to the untreated control variant, the experiment also included a distilled water control. Control with distilled water was to show whether the effect of aqueous plant extracts was due to plant material or just water. The results of the experiment showed that the use of aqueous extracts contributed to the increase in grain and protein yield. The increase in grain yield ranged from 9.48% to 15.34%, and the increase in protein yield from 9.31% to 16.16%. The best effect was achieved by applying the aqueous extract of the whole banana fruit and the aqueous extract of the mix of nettle and comfrey. By applying them each year, a significantly higher yield was achieved in relation to the control with distilled water.

The development of science and technology introduces new approaches in plant breeding and various methods to increase plant productivity. One of the latest methods is the implementation of an environmentally friendly technique of using a pulsed low-frequency electromagnetic field (PEMP). The paper presents the results of the influence of the electromagnetic stimulation of soybean seeds on grain weight per plant, weight of 1,000 grains and grain yield in different agroecological conditions. In the three-year research, in the period from 2013 to 2015, the soybean variety Valjevka was used, grown with different amounts of fertilizers (control - without fertilization, 750 kg/ha and 1300 kg/ha). Before sowing, the seed was subjected to PEMP stimulation in variants: control - without stimulation and alternating magnetic field stimulation (PEMP) with induction of 30 mT and exposure time of 15 minutes. The average grain weight per plant during seed stimulation was 11.53% (12.09) higher than without PEMP (10.84). The weight of 1,000 grains with PEMP was 155.99 g, which was 2.06% higher than the weight of 1,000 grains of the variant without PEMP (152.83 g). The average soybean grain yield for all three years of research with seed stimulation was 4.85% higher (3,481.25 kg/ha) than without PEMP (3,320.14 kg/ha). Stimulation of seeds with PEMP has economic justification given the growth of soybean prices on the world stock market. The results show that the PEMP treatment of soybean seeds can significantly affect soybean grain yield and counteract side effects such as drought and lack of fertilizers.

Many studies show that in the last 20 years, the increase in production per hectare has been achieved mainly due to the creation of new varieties and the development of plant breeding. Innovations in plant breeding are the main way to find new traits, values and tolerances, which are the only ones that can respond to the increased demand for yield and more efficient production. In addition to high and stable yields, it is very important that the soybean seed has a satisfactory technological quality. Therefore, the aim of this study was to examine how the application of pulsed electromagnetic fields (PEMFs) affected the protein yield of soybean seed depending on the year, exposure time and frequency. The field trials were conducted in the experimental field of the Institute of Field and Vegetable Crops in Novi Sad, Serbia in 2010-2013. For this research, the seeds of a medium-sized variety Valjevka exposed to a pulsed electromagnetic field (PEMF) using a pulse generator and a strip applicator were used. A low frequency pulsed electromagnetic field (16, 24, 30, 72 Hz) was used at the exposure times of 0, 30, 60, and 90 minutes. The results of the research show that the application of this method can increase the yield of protein in soybean seed for more than 20%, which is a significant increase, especially in organic production, where the use of seed treatment agents is very restricted. However, this measure can also have an inhibitory effect if an adverse combination of exposure time and frequency strength is selected.

The aim of the study was to examine the effects of management practice on microbial properties of soil under soybean production. The study included 180 samples of soil under certified organic soybean production and 80 samples in conventional production system. An abundance of the examined microbial groups was assessed using the indirect dilution method, followed by plating of soil suspension on different selective media, while dehydrogenase and β-glucosidase activity was measured spectrophotometrically. Our data indicated that the management practice affected the structure and activity of microbial com­munities. A significant positive effect of organic farming on Azotobacter spp., free N-fixers and abundance of actinomycetes was identified. The influence of management system for the total number of bacteria, ammonifiers and fungi was not observed. Significantly higher dehydrogenase and β-glucosidase activity was recorded in the soils under organic farming compared to the conventional farming. The obtained results showed an increase in organic matter content, associated with organic soil management, and its positive correlation with soil microbial properties. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 30122]

In order to examine the influence of inter-row cultivation on the soybean yield, a trial was set up in the Agricultural School in Backa Topola from 2015 to 2017. Three soybean varieties were selected at the Institute of Field and Vegetable Crops in Novi Sad. Galina, Sava and Rubin were used. The trials included the different number of inter-row cultivations: control -without inter-row cultivation, one inter-row cultivation, two and three inter-row cultivations of soybean crops. Obtained results showed that an average yield of soybean increased with an increase in the number of inter-row cultivations during the soybean vegetation period. With one inter-row cultivation, the yield increase was 5.33%, with two inter-row cultivations -7.10% and with three cultivations -7.33%. In the years with a lower precipitation, the influence of intra-row cultivation was much more effective. In 2017, the increase ranged from 10.33% to 13.62%, and in 2016 from 3.09% to 4.27%. Yield was increased due to reduced evapotranspiration of soil moisture as well as prevention of descending of water into deeper layers. During summer, this allowed better water conservation in the soil for critical periods, and also increased the activity of microorganisms as well as more intensive mineralization of organic matter, which ultimately influenced the yield.

Soybean yield depends on the choice of cultivar, soil fertility, cultivation practices, and weather conditions in different years. Ploughing down crop residues increases the content of soil organic matter, and thereby positively affects soil fertility. The use of crop residues as an energy source has been promoted in recent years. It would be wrong to refer to this as a renewable energy source as the removal of crop residues from agricultural fields reduces and ultimately damages soil fertility, which in turn leads to reduced yield and a crop residue decrease in the future. Due to the reduced application of manure and organic fertilisers, it is necessary to return crop residues to the soil to preserve soil structure and prevent soil fertility decline. The effect of ploughing down crop residues of preceding crops on soybean yield has been the focus of studies for eleven years. Ploughing down maize crop residues resulted in the soybean yield increase by about 11.69%, i.e. the annual yield increase ranged from 2.89% to 15.94%.

Six varieties were chosen from three different maturity groups: Galina and NS Princeza (0), Sava and NS Apolo (I), and Rubin and NS Zita (II) in order to examine the effect of priming on germination energy depending on soybean seed age. The seeds were produced in the period from 2012 to 2014, i.e., one- to three-year-old seeds were used. The following treatments were used for priming: distilled water - hydropriming (H2O), ascorbic acid 250 mg/l (ASA), folic acid 15 mg/l (Fol.), hydrogen peroxide 1% (H2O2), and control - non-treated seeds (C). Results showed that the effects of priming depended on the variety, seed age, as well as on the applied treatment. Some varieties reacted to priming very well, while others had an inhibited reaction, so germination energy was significantly reduced. Rubin variety had the most favourable reaction, whereby all treatments of this variety led to an increase of quality, with an average increase of 2-8%. The application of primers on one-year-old soybean seeds had a weaker effect than on two- and three -year-old seeds. However, one-year-old seeds had minor oscillations in quality due to priming. The application of priming on one-year-old seeds can lead to an increase or decrease of germination energy by 3%, while two- and three-year-old seeds reached 7%. The results showed that seed priming in ascorbic acid had a positive effect, while the application of other primers did not affect the value of germination energy, nor did it lead to a decrease of its value. Ascorbic acid activity led to the largest increase in the quality of three-year-old soybean seeds by 2.83%, while the increase in the quality of two- and three-year-old seeds was 1.87%. Therefore, we can conclude that there is no universal use of one single primer, as it might not be suitable for each particular variety and can ultimately result in the seed quality decrease.

The aim of this study was to isolate and identify Bradyrhizobium japonicum strains on the basis of molecular characteristics. From root nodules of different soybean cultivars were obtained 56 isolates, characterized according to morphological, cultural, and biochemical properties. Among these isolates, 33 isolates showing resemblance with Bradyrhizobium sp. were further subjected to molecular identification. Following DNA extraction, a partial 16S rDNA gene sequence from the isolates was amplified by PCR using universal primers fD1 (27F) and rP3 (1492R). Purification and sequencing of the amplified fragments were done in the bio­technology company Macrogen, Seoul, South Korea. Sequences were analyzed using the pro­gram FinchTV and BLAST (Basic Local Alignment Search Tool) and compared to sequences in GenBank and the Bradyrhizobium ID-database for identification. Comparison of the se­quences with the Bradyrhizobium ID-database showed that all tested isolates were identified as Bradyrhizobium japonicum. Each isolate was deposited in the NCBI GenBank database under a unique accession number. Identification of Bradyrhizobium species from root nodules of soybean is of great importance because the symbiosis between rhizobia and legumes are a cheaper and usually more effective agronomic practice for ensuring an adequate supply of nitrogen for legumes, while preserving and improving fertility and productivity of soils. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31022]

The aim of this study was to examine optimal time of soybean seed priming and effect of primers under salt stress conditions. Testing was performed at the Institute of Field and Vegetable Crops, Novi Sad, on Galina seed variety. Optimal priming time was determined by immersing seed into: KNO3 (1%), H2O2 (0.1%), and H2O with the duration of 6 h, 12 h, 18 h, and 24 h. After drying until the initial moisture, the seed was placed for germination and after eight days germination was determined. In the second part of the experiment, the seed was immersed into: KNO3 (1%), H2O2 (0,1%), and H2O after which their effect on germination energy and seed germination under simulated salinity conditions was examined. Simulated salinity conditions represented substrate for germination to which NaCl in different concentrations was added (0, 50, 100, 150, 200 mM). Results of the research showed that the six-hour priming of seed was the best with all primers. The percentage of seed germination linearly reduced with the increase of priming time. The research has shown that seed priming represents a favorable technique for the reduction of a negative effect of NaCl on germination energy and soybean seed germination, and the best effect is accomplished with the use of KNO3.

Copyright of Journal of Agricultural Sciences, Belgrade is the property of University of Belgrade, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agricultural Sciences, Belgrade is the property of University of Belgrade, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)