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This paper presents an analysis of the process of cleaning three alfalfa seed lots using seed processing equipment. The effect of the initial quality of alfalfa seed on the losses and gains of processed alfalfa seed was examined. The quality of alfalfa seed during processing was also examined. During alfalfa seed processing, the losses and gains of processed alfalfa seed depend on the initial seed purity and the technology applied. The experiment was carried out at the seed processing centre of the Institute for Forage Crops in Kruševac. A total of three lots of natural alfalfa seed were processed using the fine-cleaning machine Alfa-4 (Damas, Denmark) and the magnetic machine IV (Emcek Gompper, Germany). The following seed processing parameters were observed in the present study: pure seed (%), weed and other seed crops (%), inert matter (%), seed mass (kg), seed loss (%) and processing output (%). On the basis of the results obtained, it is possible to analyse the processing of alfalfa seed and the required equipment adjustments during the process. The equipment adjustments during processing were made depending on the quantity and type of weeds and other substances found in the natural seed.

In agricultural production, pests and diseases of agricultural crops, as well as weed plants, cause significant losses in the yield and quality of agricultural products. One of the most effective ways of fighting is the use of a wide range of chemicals called pesticides. In accordance with the EU Directives 2009/128/EC and 2006/42/EC underlying the standard EN 13790, the Plant Protection Administration of the Ministry of Agriculture and the Environment of the Republic of Serbia has established a framework for the control of sprayers and mist blowers. Maintaining sprayers for pesticide application in a good state of repair and proper working order reduces their harmful effects on human health and the environment. The nozzle is one of the most important parts of plant protection machines, responsible for the following major functions: delivery of a given amount of liquid in a unit of time, dispersion of the liquid by making droplets of different sizes and forming a stream of a particular shape. Testing of the working safety of sprayers and nozzles was carried out in accordance with the European Standard EN 13790 which specifies the methods and equipment for inspection. The flow rate of nozzles was measured by an S001 nozzle tester (AAMS-Salvarani, Belgium). The measuring equipment used for testing the pesticide application device can accurately determine any deviation and irregularity in the application.

The goal of this paper was to determine the yield of different maize hybrids depending on soil type and compaction. The experiment was carried out in 2016 and 2017 on the territory of the Leskovac municipality, including three different soil types (alluvium, vertisol, and parapodzol). The experiment comprised nine hybrids of different FAO maturity groups (NS 4051, AGR DIAN, ZP 427, NS 5211, ZP 555, AS 534, NS 6030, ZP 666 and Bećar). The highest average yields were achieved on alluvium, then on parapodzol, and the lowest yields were obtained on vertisol. The highest average yields on all examined soil types were achieved in the FAO 500 maturity group, and the lowest in the FAO 400 maturity group. The highest average yield on vertisol was achieved in the FAO 500 maturity group, on parapodzol in the FAO 400 maturity group, and on alluvium in the FAO 600 maturity group. The highest average yield (11.90 t ha-1) was achieved with the ZP 666 hybrid on alluvium, and the lowest (4.60 t ha-1) with the NS 6030 hybrid on vertisol. The largest soil compaction in the ploughing layer was determined in vertisol, then in parapodzol, and the smallest in alluvium. These data on average yields indicate the convenience of certain soil types for maize production, and provide guidelines for growers to select the most yielding hybrids for their fields.

At present, spreading of mineral fertilizers in Europe is most commonly performed using centrifugal disk spreaders with attached vanes. The motion of an ideal spherical homogeneous fertilizer particle along the straight vane attached to a flat rotating disc was analyzed in this paper. The analysis was performed in the non-inertial reference coordinate system. From the assumptions introduced to enable analytical describing of the real particle motion as well as the general tools of solid mechanics, the ordinary in-homogenous second-order differential equation having constant coefficients arose. Its solution represents an approximation of the real relative motion of the fertilizer particle along the straight radial vane fixed to the flat horizontal disc rotating at a constant angular velocity. However, the solution of this kind can be very useful for the optimization of centrifugal spreader working parameters.

The aim of this study was to examine the impact of the application of mineral fertilizers with a high content of phosphorus and potassium on the productive characteristics of some small grains grown on pseudogley soils. The research was carried out in the vicinity of Kraljevo during the period 2011/2013. The experiment included wheat, winter barley and triticale and 3 variants of fertilizers (K − control; V1 − N80 P60 K60; V2 − N80 P80 K80 and V3 − N80 P100 K100). In addition to grain yield, absolute mass and hectoliter mass were observed. The obtained results were analyzed using the analysis of variance. There were no significant differences in yield, absolute mass and hectoliter mass of the grain between small grains. The use of fertilizers with an increased content of phosphorus and potassium led to a significant increase in grain yield, absolute mass and hectoliter mass of small grains compared to control. Among the variants V1 and V2, and V2 and V3 variants, there were no statistically significant differences in the absolute mass and hectoliter mass of the grain. The average values of grain yield of small grains ranged from 1510 kg ha-1 in the control variant up to 3209 kg ha-1 in the variant with the highest dose of phosphorus and potassium fertilizers. Significant differences in grain yield were observed between the variants V1 and V2, as well as between the variants V2 and V3. The application of only mineral fertilizers on acid soils leads to relatively low yields. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31054: Razvoj novih tehnologija gajenja strnih žita na kiselim zemljištima, koristeći savremene biotehnologije]

Alfalfa is the most important perennial forage legume used for seed production and fodder. The seeds of alfalfa for sowing must be of high purity, germination and high genetic value. The initial purity of naturalized alfalfa seed significantly affect the resulting amount of processed seed in processing process. In the processing of natural seed alfalfa seed material to obtain adequate quality by law regulate used a complex machines for cleaning and sorting seeds. In the processing center of the Institute for forage crops in Globoder-Kruševac, Serbia alfalfa natural seed are processed. The six different parties of natural seeds of different purity in the range of 66 % to 85 % were processed. Also, after each stage of treatment, losses of seeds and seed rate obtained at the end of the processing were measured.

Mercantile potato harvesting is an operation that requires a quality work of potato diggers, because of the possible damage to tubers caused by the working body that can affect the quality and duration of the storage of tubers. For potatoes harvesting, the best effects are expressed by single-row and double-row diggers with a conveyor belt. This paper presents the results of exploitation tests on various potato diggers used for mercantile potato harvesting in the ecological conditions of northern Kosovo and Metohia. The aim of our study was to determine the quality of the work of potato diggers, the power consumption and surface effect. On the basis of these results, it was concluded that the total loss of potato tubers was between 5.01% (565.7 kg ha-1) and 11.50% (1,291.2 kg ha-1) according to the yields in the studied plots. During the testing the digger generated effects ranged from 0.10 ha h-1 up to 0.28 ha h-1 , with an average fuel consumption of 12.60 l ha-1 up to 19.20 l ha-1 .

For contemporary and economical livestock production, especially cattle and sheep raising, it is necessary to achieve high production of livestock feed while reducing production costs. Improving the production of perennial grasses and legumes creates a good basis for the development of livestock production in different agro-ecological conditions of Serbia. It also establishes a link between farming and animal husbandry, which is of particular importance for the preservation and higher fertility of arable land and the protection of agro-ecosystems. An important factor for the cheaper production of livestock feed is the possibility to provide sufficient quantities of quality seeds at affordable prices. Production of quality seeds of local varieties of perennial legumes is possible to obtain sufficient amounts of good quality forage. Current situation in forage crop seed production of the Republic of Serbia is unsatisfactory because the seed of perennial grasses are mostly imported. Domestic production of alfalfa, red clover and birdsfoot trefoil met domestic needs only in some years. Seed of imported varieties are often not satisfactory because those varieties are not adapted to our local agro-ecological conditions. The present results provide the basis and direction for further researches that may provide solutions to increase seed yields and which will be widely accepted in practice, which will make the production more cost-effective. Institute for forage crops Kruševac is making a significant contribution to the development of technology of seed productions, especially alfalfa, red clover and perennial grasses. Therefore the role of the Institute is very important and necessary link between production, processing and trading seeds of perennial legumes and grasses in Serbia.

Operation quality of an ear-picking device for mercantile maize is defined by the grain losses, quality of harvested mass and by straw chopper cutting height. Contemporary solutions for such machines should enable quality maize harvesting in various conditions, where losses and damage of grains would not exceed tolerable values. This paper gives the results of an exploitation study on operation quality of two ear-picking device types of self-propelled combine harvesters for mercantile maize in agroecological conditions of the Toplica County. The investigation aimed to establish operation quality, operation productivity and fuel consumption. During the first phase, operating conditions were established, whilst in the second phase operating effects were established, as affected by the defined parameters. The first type of ear-picking device for mercantile maize showed better operation quality, comparing than the second one, under similarly defined parameters. Mass harvested by the first device contained over 95.24% undamaged and 8.25 % unshucked ears, with shelling degree of 1.52%. Grain losses varied from 0.52-1.10%. In the second type, there were around 93.17% of whole ears and 9.10% of unshucked ones, with grain losses of 0.73-1.65%. Shelling degree was 2.93%. Driving velocity significantly affected the increase in straw chopper cutting height, so it was 19.2-23.6 cm for the first device type, and 19.7-32.3 cm for the second one. Operation productivity was between 0.96 and 1.23 ha h-1.

This study has been aimed to determine degree of weediness, grain yield and yield components of winter barley, as affected by fertilization system and liming. For that reason, the field trial with three fertilization variants and four barley cultivars was carried out during 2009, in the Center for Agricultural and Technological Research at Zaječar. First fertilization variant included NPK nutrients (120:80:53), in the second one phosphorus amount was doubled, and in the third one were applied 5 t ha' 1 of lime fertilizer "Njival Ca" and 20 t ha' 1 of manure together with mineral fertilizers. The following four winter barley cultivars were involved in the trial: Jagodinac, Record, Premium and Crystal. The trial was set on vertisol soil type, in random complete block design with three replications. This study results show that the highest weediness degree (3.8) was observed at the control variant (without fertilization), while it was lower at the fertilized variants. The highest average grain yield (4340 kg ha'1) was reached at the variant with manure, NPK and lime fertilizers, and the lowest one (3303 kg ha'1) at the first variant. Similarly, the greatest 1000 grain mass and hectoliter mass were also observed at the variant where NPK fertilizer, lime fertilizer and manure were applied. Application of fertilizers with increased amount of phosphorus, as well as lime and manure combination, significantly decreased degree of weediness and increased grain yield of winter barley.

This paper shows the losses created during alfalfa mowing process performed by oscillatory mower with classic cutting apparatus. The losses detected during research process have been divided into two groups: losses caused by increased incision height (over 6 cm), and losses caused by crushing. The total losses made during mowing by the tested mower were calculated by adding the incision height losses and crushing losses. The research results indicate that the minimal losses caused by the incision height are 0.57 % of yields, at the aggregate mowing speed of 3.82 km/h. Aggregate mowing speed increase tend to slightly increase the losses up to maximum values of 1.17 % at the mowing speed of 8.17 km/h. The crunching losses ranged from minimal 0.31 % at the minimal aggregate mowing speed. The average total losses were 1.18 % of yields at the average aggregate mowing speed of 5.76 km/h.

Intensive crop production is based on the use of various means of mechanization. Significant place in applied mechanization take sowing aggregates. Emphasizing the importance of applied sowing aggregates and their technological characteristics and quality of work (appropriate and optimal deployment of seed depth, length and width of the sowing layer) is understandable, especially if one takes into account the fact that an omission made in the technological process of sowing later practically almost can't be removed. The aim of our study was based on field-laboratory and terrain to test the mechanical seeders 634.23 IMT in sowing rye, determination quality and reliability of drill work. Based on these results it was concluded that in terms of proper adjustment of drill and well-executed presowing preparation, planter IMT 634.23 can achieve a good distribution of seeds of rye on the surface, with a spacing of 40-60 mm over 60% of seeds. Transverse distribution of seed rye was satisfactory, given that the highest content of rye seeds were grouped at a distance of 120-140 mm and amounted to over 65%. No marked significant differences in seeding depth intervals in the group which have been investigated. IMT 634.23 seeder can be used successfully for sowing rye and it belongs to a group of reliable seeder with good productivity and reliability that has been shown during operation.

Production of seed of an onion using mother bulbs is very complicated with many characteristics. First of all is manner of production (two or three annual cycle), sort features, mass of mother bulbs, length of mother bulbs, planting time agro ecological conditions. In order to establish effects of storing temperature and mass of mother bulbs on qualitative and quantitative features we undertake these experiments. Investigation conducted using onion bulbs (old domestic sort - Prizrenski pogačar) with mass of 5-25g and 50g. Bulbs were stored 90days before planting at the temperature of 4-6°C, 10-12 °C and 16-18°C. Storing temperature exert influence on number of floral stalks, time of flower formation, yield and quality of seed. High (16-18ºC) and low (4-6°C) temperature inhibit or retarded formation of floral primordial. Optimal temperature was 10-12ºC. Planting of larger bulbs produce greater number of floral stalks in comparison to small bulbs. Influence of vernalization temperature on number of floral stalks on bulbs with larger mass was insignificant. .

In the study the results of macro field trial with some ZP and NS corn hybrids have been shown. The field trial was accomplished in 2001 and 2002 year in the area of Toplica. The soil on which the field trial was accomplished was smonitza. The antecedent culture was the winter barley. The insemination was performed at the beginning of May. In the macro field trial 19 ZP and NS corn hybrids of different length of vegetation were included. The results showed that the harvest lacked from 15-26% of plants in relation to the number of showed ones. The content of the damp in the harvest went from 20,7 to 28,8%. The average crop was from 4,73 (NS dunav) to 6,47 t/ha (NS zenit). .