Search

Novi rekonstruisani kombajn ELEKTRONIK SP-09, je samohodna mašina koja je od svoga predhodnika ELEKTRONIK SP-07 zadržala princip jednostranog ubiranja polovine reda žbunastog jagodastog voća. Mašina je posebno prilagođena za branje remontantnih sorti maline bez potpore, mada se može uspešno koristiti i za druge vrste voća žbunaste forme. Razdeljivač usmerava jednu polovinu račvastog žbuna do jedinice za protresanje, gde vibrirajuće palice odvajaju bobice. Iz mase plodova, koji se transportuje kosom transportnom trakom na horizontalnu, struja vazduha iz ventilatora uklanja primese. Transportna traka može puniti male gajbice, a kapacitet prostora za odlaganje punih gajbica je oko 200 kg. Hidrostatički pogon pokreće SUS motor snage 50 kW. Parametri rada radnih delova se podešavaju da bi otpali samo zreli plodovi. Mogu se podešavati: - amplituda i frekvencija oscilovanja, - prečnik valjka i dužina palica, - prečnik palica, - radna brzina berača-kombajna. Među najvažnijim opštim konstruktivnim karakteristikama ističu se: - jednostavan modularni dizajn, koji omogućava: • uskladjivanje mašine sa specifičnim potrebama korisnika, • brzo i jednostavno prilagodjavanje za ubiranje različitih vrsta jagodastog voća. - pogon radnih komponenata kombajna ostvaruje se pomoću odgovarajućih kombinacija hidrauličnih i mehaničkih prenosnika snage, što mu omogućava veliku prilagodljivost različitim radnim uslovima na terenu (sl. 2 i 3). - posebna oscilujuća glava sa glatkim, plastičnim palicama na otresajućoj koloni; - pred-separator za uklanjanje nečistoće manjih dimezija; - dodatni separatorski transporter, koji olakšava uklanjanje oštećenih plodova; Pogon hidrauličkog sistema čine četiri jednosmerne zapreminske pumpe stalnog protoka: P1, P2, P3 i P4. Paralelno su spregnute, a pogon im omogućava zajedničko vratilo, koje snagu od dizel SUS motora kombajna (M) preuzima preko jednostepenog kaišnog prenosnika prenosnog odnosa i=1. Ovaj tip prenosnika, uz tiši rad, jednostavnu konstrukciju i

The aim of the research was to examine the influence of sowing density on the yield of more maize hybrids of different vegetation lengths in the conditions of southern Serbia (Leskovac). For this purpose, during 2016 and 2017, an experiment was set up with 6 maize hybrids (ZP 434, NS 4023, ZP 555, NS 5051, ZP 666, NS 6030) and 3 sowing densities (71428; 57142 and 47619 plants ha-1). The experiment was set up according to the random block system in 3 repetitions and was processed by the method of analysis of variance. The results are shown as a two-year average and they showed that the average grain yield for all densities, depending on the hybrid, ranged from 9.33 t ha-1 in the hybrid NS 4020 to 11.16 t ha-1 in the hybrid ZP 555. Hybrids of medium and long vegetation period had significantly higher grain yields than hybrids with a shorter vegetation period. The average yield for all hybrids, depending on the sowing density, ranged from 10.06 t ha-1 at the highest sowing density to 10.66 t ha-1 at the medium sowing density. Hybrids with a shorter vegetation period achieved the highest average yields at the highest sowing density, while hybrids with a longer vegetation period had the highest average yields at the lowest sowing densities. The hybrids ZP 555 and NS 6030 had the highest average yields of 11.77 and 11.02 t ha-1 at medium and lower sowing densities, respectively. Based on this, it is recommended to sow hybrids of medium and longer vegetation period in the range of 57142 to 47619 plants ha-1.

Compacted soil causes weaker growth of the root system, weaker microbial activity, slowing down the absorption of water and nutrients, thus slowing down the growth of plants. Breeding plants on such soils result in reduced yields and increased production costs. This study was aimed to determine the impact of manure and mineral fertilizers on soil compaction and maize yield. The experiment was performed on the territory of the municipality of Leskovac on Smonitza soil type. The experiment included four variants of fertilization with organic and mineral fertilizers. Compaction was measured after sowing and after maize harvest, by penetrologger Eijkelkamp hardware, version 6.0, software version 6.03. The application of manure in combination with mineral fertilizers significantly reduced soil compaction. The highest compaction was recorded at a depth of 40-50 cm, after which it stagnated and slightly decreased to a depth of 80 cm. The average compaction measured after harvest was 24.10% higher than that measured after sowing. The soil moisture content was higher on plots with manure and mineral fertilizers than on non-fertilized plots. Maize yield was significantly higher in variants where manure was used together with mineral fertilizers compared to variants with the only use of mineral fertilizers and variants without fertilizers. Variants with the lowest soil compaction achieved the highest yields. The recommendation to maize producers is to apply more organic matter on heavy and compacted soils, primarily manure, but also mineral fertilizers, to have high and stable yields.

Soil fertility is a combination of mineral and biological properties of soil and the circulation of plant nutrients in the soil-plant system is constantly happening within it. In order for the root system to develop and function normally, it is necessary that there is enough oxygen in the soil. Only well-drained soils provide enough oxygen and good activity of microorganisms. Since most of the operations, from sowing to harvest, are performed with the help of heavy mechanization, soil compaction occurs and its structure deteriorates. Within compacted soil, there is a weaker development of the root system, weaker microbiological activity, slowing down the absorption of water and nutrients, thus slowing down the growth of plants. Growing plants on such soils result in reduced yields and increased production costs. The aim of this study was to determine the impact of manure and mineral fertilizers on soil compaction and maize yield. The experiment was performed on the territory of the municipality of Leskovac on smonica soil type. The experiment included four variants of fertilization with organic and mineral fertilizers. Compaction was measured after sowing and after maize harvest, by penetrologger Eijkelkamp hardware version 6.0, software version 6.03. The application of manure in combination with mineral fertilizers significantly reduced soil compaction. The greatest compaction was recorded at a depth of 40-50 cm, after which it stagnated and slightly decreased to a depth of 80 cm. The average compaction measured after harvest was 24.10% higher than that measured after sowing. The soil moisture content was higher on plots with manure and mineral fertilizers than on nonfertilized plots. Maize yield was significantly higher in variants where manure was used together with mineral fertilizers compared to variants with the only use of mineral fertilizers and variants without fertilizers. Variants with the lowest soil compaction achieved the highest yields. The recommenda

Precipitation and temperatures are of particular importance for maize production. The aim of these studies was to analyze the yields of different maize hybrids in years that were both favorable and unfavorable for their production. Thus, the yield of maize in 2020 and 2021 was analyzed in the area of Southern Serbia (Leskovac). The year 2020 can be considered favorable for the production of maize, primarily due to the amount of precipitation during the vegetation (436 mm) and its proper distribution in the summer months. The year 2021 can be considered unfavorable for the production of maize, which is especially evident by the small amount of precipitation during the growing season (219 mm). The influence of the year, especially the climatic conditions of the year, was very pronounced. Thus, the average yield in 2021 was lower by 36% compared to 2020. The influence of hybrids on yield was pronounced, and differences in yield were statistically very significant. Hybrids with a shorter vegetation period had good yields in the unfavorable (dry) year, all due to the earlier passing of silking, fertilization, and grain formation phases. In years favorable for maize production, such as 2020, hybrids with a longer vegetation period showed their genetic potential for yield and were more dominant than hybrids with a shorter vegetation period. If maize is grown on dry soil, it is recommended to sow more hybrids of different vegetation lengths, for safer production.

This paper presents the tests results of three types of hay mowing machines (later in text: mowers), namely a self-propelled oscillatory mower-conditioner and two tractor-mounted mowers with oscillatory and rotary blades, used to mow alfalfa grown under dry land conditions in the region of central Serbia during three seasons in 2014, 2015 and 2016. Although characterized by older design, they are still commonly used at smaller and medium size farms in this region. Therefore, their optimal exploitation parameters are still of large importance for hay quality and production efficiency and sustainability. The exploitation parameters of all three mowers generally increased linearly with higher speeds, having high R2 values (over 0,8), with rare exceptions. The regression coefficients b clearly showed that the self-propelled mower-conditioner achieved maximum increase in production performance (b = 0,3606), compared with the oscillatory (b = 0,1158) and rotary mowers (b = 0,1414). Mower design had a significant (p ≤ 0,001) effect on cutting and chopping losses, production performance, and specific fuel consumption (p ≤ 0,05). The tests confirmed the superiority of the self-propelled mower over the two mowers aggregated with tractors.

Zeolite improves the structure of the soil and reduces acidity, which is of great significance for agricultural production that happens on soils with low pH values. It has shown exceptional results in improving soil characteristics, thus increasing the yield and quality of cultivated plants. The aim of our study was to determine the yield and some qualitative properties of numerous wheat varieties, depending on the mineral fertilizers and zeolites application. The experiments were performed in 2018/19 and 2019/20, in the area of Southern Serbia (Bojnik). The research involved 4 wheat varieties and 4 variants of fertilization, including mineral fertilizers and zeolite. The combination of mineral fertilizers and zeolites did not show noteworthy differences in the mass of 1000 grains when it comes to both varieties and fertilization variants. Hectolitre weight of grain was significantly higher on the variant with a combination of mineral fertilizers and zeolites than on the control variant. All fertilization variants had a significantly higher grain yield compared to the control variant. The variant on which the combination of mineral fertilizers and a higher dose of zeolite were applied achieved a significantly higher grain yield compared to the variant with mineral fertilizers. Varieties Pobeda and Nikol, with the application of mineral fertilizers and zeolite combination, achieved the highest yields. On acid soils, it is necessary to apply fertilizers and soil improvers so that the yields of cultivated plants will be satisfactory.

Zeolite is well known for the improvement of the structure of the soil due to the fact that it reduces its acidity, which is of high importance for agricultural production that takes place on soils with low pH values. It has shown exceptional results in improving soil characteristics, thus increasing the yield and quality of cultivated plants. The aim of our study was to determine the yield and some qualitative properties of numerous wheat varieties, depending on the mineral fertilizers and zeolites application. The experiments were performed in 2018/19 and 2019/20, in the area of Southern Serbia (Bojnik). The research involved 4 wheat varieties and 4 variants of fertilization, including mineral fertilizers and zeolite. The research results demonstrated that there were no major differences in the 1000 grains weight, regardless of the variety of wheat or variant of fertilization. The hectoliter grain weight of the wheat variant which was treated with the combination of mineral fertilizers and a higher dose of zeolite was considerably higher than the control variant weight. All fertilization variants had a significantly higher grain yield compared to the control variant. The variant on which the combination of mineral fertilizers and a higher dose of zeolite were applied achieved a significantly higher grain yield compared to the variant with mineral fertilizers. The application of zeolite in combination with mineral fertilizers increased the wheat yield as compared to those that were treated with mineral fertilizers alone, by an average of 370 kg ha-1. In addition to the selection of varieties (Pobeda and Nikol), the application of a combination of mineral fertilizers and zeolites proved to be effective for growing wheat on acidic soils in southern Serbia.

Wheat sowing at the optimum time is very important, especially from the aspect of vegetation length, timely wading and rooting of plants, plant development, nutrient utilization rate, and ultimately total wheat yield. It is often the case that due to unfavorable climatic factors, such as drought or heavy rainfall, a delay in the removal of pre-crop and similar occasions. sowing is not carried out at the optimum time. In this case, the plants are underdeveloped, some of them collapse during the winter and in the spring some stages of development are shortened, which altogether results in diminished yields. The paper shows the yield and some components of grain quality of several varieties of wheat sown in the optimal period (October) and in the late-term (early December). The experiments were carried out in 2016/17 and 2017/18, in the area of Southern Serbia (Leskovac) with 5 wheat varieties (Obsesija, Avenue, Sosthene, Farineli and Darija), under the same agro-ecological conditions on alluvium soil. Sowing in 2016/17 was done on October 30, and in 2017/18 on December 8. The results of the experiment show that the average yield of sowed wheat in the optimal period was 6.776 kg ha-1 and those sown in the delayed period 5.091 kg ha-1. The largest yield reductions were observed for the Avenue and Farineli varieties (2,490 and 1,960 kg ha-1). Also, the mass of 1000 grains and hectolitre mass were lower in delayed sowing. These data indicate the importance of an optimum deadline for sowing wheat, which is often not respected in production.

It frequently occurs that due to unfavorable climatic factors, sowing is not carried out at the optimum time so that the sowing must be done in the delayed sowing period. The aim of our research was to determine the yield and some qualitative components of several wheat varieties sown at the optimum time and in the delayed sowing time. The experiments were carried out in 2016/17 and 2017/18, in the area of Southern Serbia (Leskovac) with 5 wheat varieties (Opsesija, Avenue, Sosthene, Farinelli, and Darija), under the same agro-ecological conditions on alluvium soil. Sowing in 2016/17 was done on October 30th, and in 2017/18 on December 8th. According to the results of the experiments, it can be concluded that the grain moisture, 1000 grain weight, and hectolitre weight did not differ significantly between sowing terms, while there were significant differences among the varieties. The grain yield varied significantly, both depending on the sowing term and the wheat variety. The average decrease in yield in the delayed term compared to the optimal term was 24.8%. Thus, in the optimal term sowing varieties Avenue and Farinelli had the highest yields (7,760 and 7,170 kg ha-1), while in the delayed time sowing varieties Darija and Avenue had the highest yields (5,370 and 5,290 kg ha-1). The Darija variety had the least decrease in yield in the delayed sowing time, so we can recommend it for sowing in this area in the delayed term.

Proper protection and quality work of sprayer enable the optimization of the pesticide application and reduces the harmful effects on the environment and human health. The efficiency of the implemented protection is reflected in several aspects, and one of the most important is the quality of the work of sprayers, that is, the equality of pesticides distribution with nozzles. The paper presents an analysis and comparison of test results in the framework of the inspection of field crop sprayers in the exploitation conditions of central Serbia, in accordance with European standards EN 13790, which prescribes methods and equipment for inspection. The aim of the research was to determine the quality of the work of chests and the uniformity of the flow of various sprays, depending on the defined parameters. The test equipment used 'AAMSSALVARANI' measuring equipment, and the flow of the nozzles was measured by the SN S001 individual nozzles. On the basis of the obtained results, it was concluded that the average values of the flow of the sprayer amounted to 0.954 l min-1 (typ A), 1.169 l min-1 (typ B), or until 1.190 l min-1 (sprayer typ C), where the coefficient of variation was in the range 12.24% to 29.49%., Pravilnom zaštitom i kvalitetnim radom prskalica omogućuje se optimizacija aplikacije pesticida i smanjuje štetni uticaj na životnu sredinu i zdravlje ljudi. Efikasnost izvedene zaštite ogleda se sa više aspekata a jedan od najznačajnijih je kvalitet rada prskalica, odnosno uniformnost distribucije pesticida rasprskivačima. Rad predstavlja analizu i upoređenje rezultata ispitivanja u sklopu inspekcijske kontrole ratarskih prskalica u eksploatacionim uslovima centralne Srbije, u skladu sa evropskim normama EN 13790 koji propisuje metode i opremu za obavljanje inspekcije. Cilj istraživanja je bio da se utvrdi kvalitet rada prsaklica i uniformnost protoka različitih rasprskivača u zavisnosti od definisanih parametara. Za ispitivanje je korišćena merna oprema 'AAMSSALVARANI', a protok rasprskivača je meren pomoću ispitivača pojedinačnih rasprskivača SN S001. Na osnovu dobijenih rezultata zaključeno je da su prosečne vrednosti protoka rasprskivača iznosile 0,954 l min-1 (tip A), 1,169 l min-1 (tip B), odnosno 1,190 l min-1 (tip C), pri čemu je koeficijent varijacije bio u rasponu 12,24% do 29,49%.

The paper presents the three years efficiency results (2011-2013) of the work and ways of harvesting (three types of mowers, with or without spreading the forage) influencing the quality of the forage (the content of crude protein and crude fiber) during the three days drying process. These results indicate that the harvesting method can strongly affect the work efficiency, energy consumption, the forage drying intensity and the quality of forage used for hay and haylage preparation. The best quality of the forage was achieved when a drum rotating mower PÖTTINGER CAT 185 was used. Negative correlation was found between content of crude protein and the crude fibre content, depending on the type of mower, varying in the range between r= -0.978 and r= -0.882 (PÖTTINGER CAT 185 r= -0.882 P≤0.05 to JF STOLL SB 200 r= -0.978 P≤0.001).

Wheat has high demands in terms of fertility and physical properties of the soil. The most successful cultivation is on fertile soils, where pH is 6.8-7.2. The soil is the basic substrate of plant rooting, and root growth depends on the depth of the layer, plant species, soil compaction, moisture, etc. The aim of this paper was to determine the yield of different varieties of wheat depending on the soil type and compaction. The trial was set during 2016/17. and 2017/18. in the territory of south Serbia (territory of Leskovac municipality), on two different types of soil (alluvium and vertisol). Four varieties of wheat were included in the experiment (Darija, Avenue, Carica and Sosthene). Compaction was measured after sowing and after harvest of wheat, with penetrometer Eijkelkamp hardware version 6.0, software version 6.03. The soil type and variety significantly influenced the average yield of wheat. Significantly higher average yields of all varieties of wheat were gained on the alluvium, related to the vertisol. Varieties Avenue and Sosthene had the highest average yields that were significantly higher than yields of varieties Daria and Carica, among which there were no significant differences. The higher soil compaction of the soil in the ploughing layer was on vertisol related to the alluvial soil. These data on average yields and soil compaction indicate the benefits of individual soil types for the wheat production.

The effect of movement of tractors and mobile systems on soil compaction and the yield of various maize hybrid. The aim of this paper was to determine the yield of different varieties of wheat depending on the soil type and compaction. The trial was set during 2016/17. and 2017/18. in the territory of south Serbia (territory of Leskovac municipality), on two different types of soil (alluvium and vertisol). Four varieties of wheat were included in the experiment (Darija, Avenue, Carica and Sosthene). The soil type and variety significantly influenced the average yield of wheat. Significantly higher average yields of all varieties of wheat were gained on the alluvium, related to the vertisol. Varieties Avenue and Sosthene had the highest average yields that were significantly higher than yields of varieties Daria and Carica, among which there were no significant differences. The higher soil compaction of the soil in the ploughing layer was on vertisol related to the alluvial soil. These data on average yields and soil compaction indicate the benefits of particular soil types for the wheat production.rids in the conditions of Southern Serbia, Cilj rada bio je utvrditi utjecaj različitih pova tala i zbijanja tla na prinos različitih sorata pšenice. Istraživanje je provedeno tijekom 2016/17. i 2017/18. godine u južnoj Srbiji (područje općine Leskovac) na dva različita tipa tla (aluvij i vertisol). Istraživanje je uključivalo četiri sorte pšenice (Darija, Avenue, Carica i Sosthene). Tip tla i sorta pšenice značajno su utjecali na prosječni prinos pšenice. Značajno veći prosječni prinos svih sorata zabilježen je na aluvijalnom tlu u odnosu na vertisol. Sorte Avenue i Sosthene imale su najveći prosječni prinos koji je bio značajno veći u odnosu na prinos sorti Darija i Carica između kojih značajne razlike nisu utvrđene. Veća zbijenost tla u sloju na dubini oranja zabilježena je na vertisolu u odnosu na aluvijalno tlo. Dobiveni podaci o 7h/ub prosječnim prinosima i zbijanju tla ukazuju na utjecaj određenog tipa tla na proizvodnju pšenicu.

Proper seed distribution over area and depth is the essential condition that provides later uniform plants distribution over the vegetation space. Paper presents statistical analysis of two drills accuracy results in winter rye sowing. Experiment was done in north Kosovo, during rye sowing with two mechanical seed drills, OLT Gama and IMT 634.23. Besides the comparative analysis of the sowing results achieved by these two drills, in the paper is tested and verified the applicability of Gaussian function for analytical description of longitudinal, transverse and depth distribution of winter rye seed at the experimental plot., Pravilna raspodela semena po površini i dubini predstavlja osnovni uslov za obezbedjenje ravnomerne raspodele biljaka u vegetacionom prostoru. U radu je predstavljena statistička analiza rezultata ispitivanja tačnosti distribucije semena dve uskoredne sejalice u setvi ozime raži. Ispitivanja su izvedena na severu Kosova, u toku setve semena raži primenom dve sejalice Olt Gama 14 i IMT 634.23. Osim komparativne analize rezultata setve koji su dobijeni primenom ove dve sejalice, u radu je testirana i proverena primenljivost Gausove funkcije za analitičko opisivanje uzdužne, poprečne i raspodele semena ozime raži po dubini na eksperimentalnoj parceli.

The paper presents an analysis and comparison of the results of exploitation testing the different machines for soil tillage under conventional and reduced tillage, as well as evaluating the quality of the two types of sowing in the production of buckwheat and winter rye, in the conditions of northern Kosovo and Metohia. The previous crop was mercantile maize. The aim of this study was to determine the effects of the aggregate labor indicators for tillage and seeding, in the production of winter rye and buckwheat, and the results will enable proper selection of appropriate technological and technical systems and pointing out the advantages and disadvantages of the applied systems for tillage and seeding. In a variant of conventional tillage in relation to reduced tillage fuel consumption was higher by 27.41 up to 27.73%, while the yields of buckwheat was lower by 22.02%, and winter rye up to 20.18%. Measured values of longitudinal and lateral distances, and depths of buckwheat and rye seeds, are numerically processed using inverse distance interpolation method. Consequently, an appropriate contour maps that present distributions of relative frequencies with respect to longitudinal and lateral seeding distances, as well as seeding depths, are drawn. These maps clearly illustrate accuracy quality of work and operational stability of two analyzed seeding machines having quire different designs of seeding apparatus, in the working conditions of buckwheat and rye seeding., Rad predstavlja analizu i upoređenje rezultata eksploatacionih ispitivanja različitih mašina za obradu zemljišta u okviru konvencionale i redukovane obrade, kao i ocenu kvaliteta rada dva tipa sejalica u proizvodnji heljde i ozime raži u uslovima severnog Kosova i Metohije. Predkultura je bila merkantilni kukuruz. Cilj istraživanja je bio da se utvrde pokazatelji efekata rada agregata za obradu zemljišta i setvu u proizvodnji heljde i ozime raži, a dobijeni rezultati omogućiće pravilan izbor odgovarajućeg tehnološko-tehničkog sistema i ukazati na prednosti i nedostatke primenjenih sistema za obradu zemljišta i setvu. U varijanti konvencionalne obrade u odnosu na redukovanu obradu potrošnja goriva je bila veća za 27,41-27,73%, pri čemu su ostvareni prinosi heljde bili manji za 22,02%, a ozime raži za 20,18%. Kvalitet rada sejalica obuhvatio je određivanje uzdužnog, poprečnog i rasporeda zrna po dubini setvenog sloja. Izmerene vrednosti uzdužnih i poprečnih rastojanja kao i dubine setve heljde i raži, su numerički obrađene metodom interpolacije inverzne udaljenosti. Na osnovu toga, urađene su odgovarajuće konturne mape koje predstavljaju distribucije relativne učestalosti u odnosu na uzdužna i bočna rastojanja semena pri setvi, kao i dubinu setve. Ove mape jasno pokazuju kvalitet rada i radnu stabilnost dveju analiziranih sejalica sa različitom konstrukcijom setvenog aparata, u uslovima rada pri setvi heljde i raži.

Forage harvesters should chop crop mass to particles having short and uniform lengths. Length distribution of forage particles represents an important parameter for ruminant's diet formulation, especially for dairy cattle. During silage production, harvest considerations should be focused to obtaining the adequate particle size distribution of the ensiling crop particles. This paper presents the results of mining studies of three different forage harvesters at harvesting maize for silage preparation. The aim of this testing is to determine the operational characteristics and quality of the following forage harvesters Claas Jaguar 675, Zmaj 350 and John Deere 5820. The average yield of the mass was about 26 t ha(-1). Based on these results, it is concluded that the losses due to cutting height range from 3.83% to 5.97%. Clear relation between working velocity of forage harvesters and losses caused by inappropriate cutting height was proved. These two parameters are directly proportional, i. e. their connection is strong (R-2 = 0.88) and linear. All three harvesters achieved fairly acceptable cut lengths of harvested maize particles. However, experimental results verify the operational supremacy of forage harvesters Class Jaguar 675 and John Deere 5820 with relation to the long used forage harvester Zmaj 350. The minimum deviation achieved for long chopped mass in relation to the setting, was recorded when storing silage with silage Claas Jaguar 675 in which the average length of chopped mass was 9.97 mm, where as for the fraction of length up to 10 mm was 69.87%.

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., U poljoprivrednoj proizvodnji, štetočine i bolesti poljoprivrednih kultura, kao i korovske biljke svake godine prouzrokuju značajne gubitke u prinosu i kvalitetu poljoprivrednih proizvoda. Jedan od najefikasnijih načina borbe jeste primena brojnih i različitih hemijskih sredstava, koja se nazivaju opštim nazivom pesticidi. U skladu sa Direktivama Evropskog parlamenta 2009/128/EC i 2006/42/EC, kojima je osnova standard EN 13790, koji propisuje obavezni pregled mašina za zaštitu bilja, Uprava za zaštitu bilja Ministarstva poljoprivrede i životne sredine Republike Srbije uspostavlja okvir za kontrolu sistema prskalica i orošivača. Upotrebom tehnički ispravnih i kontrolisanih ratarskih prskalica za primenu pesticida smanjuje se njihov štetni uticaj na zdravlje ljudi i životnu okolinu. Jedan od najznačajnijih delova mašina za zaštitu bilja predstavljaju rasprskivači. Oni obavljaju najvažnije funkcije, kao što su: propuštaju zadate količine tečnosti u jedinici vremena, raspršuju tečnost praveći kapljice odgovarajućih veličina i formiraju mlaz odgovarajućeg oblika. Testiranje radne ispravnosti prskalice i rasprskivača vršeno je u skladu sa evropskim normativom EN 13790, koji propisuje metode i opremu kojom se obavlja inspekcija. Protok rasprskivača je meren pomoću ispitivača pojedinačnih rasprskivača S001 belgijskog proizvođača 'AAMS-Salvarani'. Primenom merne opreme za ispitivanje ispravnosti rada uređaja za primenu pesticida, merenjem je moguće tačno ustanoviti svako odstupanje i nepravilnost u radu. Dobijeni rezultati ukazuju na to da postoje značajna odstupanja ispitivanih parametara.

Cilj ovoga rada bio je da se utvrdi prinos različitih hibrida kukuruza (Zea mays L.) u zavisnosti od tipa i sabijenosti zemljišta. Ogled je postavljen tokom 2016. i 2017. godine na teritoriji opštine Leskovac, na tri različita tipa zemljišta (aluvijum, smonica i parapodzol). U ogledu je bilo uključeno 9 hibrida kukuruza različitih FAO grupa zrenja (NS 4051, AGR DIAN, ZP 427, NS 5211, ZP 555, AS 534, NS 6030, ZP 666 i Bećar). Najveći prosečni prinosi dobijeni su na aluvijumu, potom parapodzolu, a najmanji na smonici. Najveći prosečan prinos za sve tipove zemljišta dobijen je gajenjem hibrida iz FAO grupe zrenja 500, a najmanji gajenjem hibrida iz FAO grupe zrenja 400. Na zemljištu tipa smonice, najveći prosečni prinos dobijen je gajenjem hibrida iz FAO grupa zrenja 500, na zemljištu tipa parapodzol gajenjem hibrida iz FAO grupe zrenja 400, a na zemljištu tipa aluvijum, gajenjem hibrida iz FAO grupe zrenja 600. Najveći prosečni prinos (11,90 t ha-1) dobijen je gajenjem hibrida ZP 666 na zemljištu tipa aluvijum, a najmanji (4,60 t ha-1) gajenjem hibrida NS 6030, na zemljištu tipa smonice. Najveća sabijenost zemljišta u orničnom sloju utvrđena je na smonici, potom na parapodzolu, a najmanja na aluvijumu. Ovi podaci o prosečnim prinosima govore o pogodnostima pojedinih tipova zemljišta za proizvodnju kukuruza i daju smernice proizvođačima za odabir najrodnijih hibrida koje žele gajiti na svojim njivama.

The dry down rate of corn grain during maturation is influenced by a large number of environmental factors and properties of hybrids, and has a major effect on corn, reaching its full maturity. This is especially important for the timely soil tillage and planting of the next culture. The aim of this research was to determine the yield and dry down rate from corn grains depending on the hybrid and the sowing term, in the agro ecological conditions of South Serbia (Leskovac). For this purpose, an experiment was made during 2016 and 2017 on the territory of the municipality of Leskovac. Soil type was alluvium. The trial was planned according to the schedule of divided land plots, set up in three repetitions. This included 6 hybrids of different FAO maturity groups and three differing sowing terms. The results of the study show that the average content of water in the grain in physiological and technological maturity, at all the hybrids and sowing terms were in 2016 significantly lower than in 2017. The highest average yields in 2016 were achieved with hybrids of the FAO maturity group 600, in the 2nd and 3rd sowing term, while in 2017, the highest yields were recorded with hybrids of the FAO maturity group 500, during the 1st and 2nd sowing term. The average rate of dry down in 2016, in all hybrids, was the highest recorded in the 1st sowing term, and in the year 2017, in 2nd and 3rd sowing term. The most intense dry down rate period in both years, at the hybrids of the FAO maturity group 400 was in the second and third week of physiological maturity, while in FAO maturity hybrids groups 500 and 600 in the third and fourth week of physiological maturity., Brzina otpuštanja vode iz zrna kukuruza je posebno važna za raniju zriobu i pravovremenu obradu zemljišta za setvu naredne kulture. Cilj ovih istraživanja je bio da se utvrdi prinos i brzina otpuštanja vode iz zrna kukuruza u zavisnosti od hibrida i roka setve, u agroekološkim uslovima Juga Srbije (Leskovac). U tu svrhu postavljen je ogled tokom 2016. i 2017. godine na teritorije opštine Leskovac, na zemljištu tipa aluvijum. Ogled je bio postavljen po planu razdeljenih parcela u tri ponavljanja i uključivao je 6 hibrida različitih FAO grupa i tri roka. Prosečni sadržaj vode u zrnu u fiziološkoj i tehnološkoj zrelosti, kog svih hibrida i rokova setve u 2016. godini, bio je značajno manji nego u 2017. godini. Najveće prosečne prinose u 2016. godini imali su hibridi FAO grupe zrenja 600 i to u II i III roku setve, dok su u 2017. godini nejveće prinose ostvarili hibridi iz FAO grupe zrenja 500 i to u I i II roku setve. Prosečna brzina otpuštanja vode u 2016. godini, kod svih hibrida, bila je najveća u I roku setve, a u 2017. godini u II i III roku setve. Najintenzivniji period otpuštanja vode bio je od druge do četvrte nedelje od početka fiziološke zrelosti i razlikovao se u zavisnosti od FAO grupe zrenja. Ukoliko kukuruz gajimo u plodoredu sa pšenicom za preporuku, na ovom području, su hibridi iz FAO grupa zrenja 400 i 500. Ukoliko ga gajimo u plodoredu sa jarim kulturama poželjni su hibridi iz FAO grupe 600, posebno u povoljnim godinama.

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., U Evropi se za rasipanje granularnog mineralnog đubriva najčešće koriste centrifugalni rasipači sa lopaticama. U ovom radu je analizirano kretanje idealne, loptaste, homogene granule đubriva duž lopatica postavljenih po rotirajućem disku. Analiza je izvedena primenom neinercijalnog referentnog koordinatnog sistema. Uvođenjem određenih pretpostavki i primenom zakona teorijske mehanike za opisivanje kretanja čestice, formirana je nehomogena diferencijalna jednačina drugog reda sa konstantnim koeficijentima. Njeno rešenje aproksimira realno relativno kretanje čestice đubriva duž ravnih radijalnih lopatica pričvršćenih za horizontalni disk, koji se obrće konstantnom ugaonom brzinom. Dobijeno rešenje se svakako može koristiti za optimizaciju radnih parametara centrifugalnog rasipača sa diskom.

The paper presents testing results of three silage combines employed in maize silage preparation in Toplica region. It is focused on determination of technical working parameters of tested machines. Achieved results verified the superiority of silage combine John Deere 5820, which produced the chopped mass having particle lengths of the smallest deviation with respect to the preset cutting length. In this case, the average length of chopped mass was 9.9 mm, having 69 % mass in the range up to 8 mm. The other two silage combines produced lower mass percentage of this fraction and larger variations of particle lengths with respect to the preset length. Minimum mass flow rate was evidenced for the silage combine Fortschrit E-286: 7.3 kg s-1 (26.3 t h-1) and the surface productivity of 0.83 ha h-1, at the average speed of 4.0 km h-1. Maximum production rate was achieved with silage combine John Deere 5820: 10.9 kg s-1 (39.1 t h-1) at average working velocity of 4.7 km h-1 and surface efficiency of 1.21 ha h-1.

Sainfoin seeds were irradiated by four different lasers (He-Ne laser, three semiconductor lasers of wavelengths 670 nm, 890 nm and of wavelength range 630-680 nm). Each group of seed was irradiated only once, using different exposure times: 1-, 2-, 3- and 4- minutes. The same procedure was applied before autumn (four months post-harvest) and spring sowing (eight months post-harvest). Laser bio-stimulation showed that the optimal operation of the laser was at 890 nm using 3- minutes exposure time in both sowing periods. Slightly weaker, but also significant (p gt = 0.01) impact on improving germination was in case of laser of 890 nm using 2- and 4- minutes of exposure time, and 630-680 nm laser using 4- minutes exposure time in both sowing periods. In the spring sowing, only laser of 632.8 nm using 3- minutes exposure time and laser of 670 nm laser between 2- and 4- minutes exposure time had significant improvement of seed germination. In the autumn sowing, He-Ne lasers (632.8 nm) using 4-minutes exposure time, semiconductor lasers of 670 nm laser using 3- minutes exposure time, and 630-680 nm laser using 3-minutes exposure time, also significantly (p gt = 0.01) increased seed germination compared to control.

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., Lucerka je najznačajnija višegodišnja krmna leguminoza koja se osim za krmu koristi i za proizvodnju semena. Seme lucerke za setvu mora biti visoke čistoće, klijavosti, kao i visoke genetske vrednosti. Početna čistoća naturalnog semena lucerke značajno utiče na dobijenu količinu dorađenog semena pri procesu dorade. Takođe utiče i na utrošak energije u procesu dorade, kao i ljudskog rada i količinu otpada. Tokom dorade naturalnog semena lucerke za dobijanje semenskog materijala odgovarajućeg kvaliteta koji je zakonski regulisan koriste se složene mašine za prečišćavanje i sortiranje semena. U doradnom centru Instituta za krmno bilje u Globoderu-Kruševac, Srbija dorađivano je naturalno seme lucerke šest različitih partija čistoće od 66% do 85%. Dorada semena ima zadatak da se seme pripremi za setvu, klijanje i nicanje, kao i čuvanje u skladištima do momenta setve. Dorada se izvodi na više složenih mašina koje rade na različitim principima u sukcesivnom nizu što zavisi od ulazne čistoće semena. Veoma je važno da razlika između količine čistog semena koja se laboratorijski proceni i stvarne količine dobijenog semena na kraju procesa dorade bude što manja. Količina dobijenog semena lucerke i ostalih sitnozrnih kultura pri doradi direktno zavisi od udela korovskih vrsta i ostalih primesa u naturalnom semenu. Seme visoke čistoće, sa malim udelom semena štetnih korova koji otežavaju i poskupljuju proizvodnju, dovodi i do visokog randmana. Efkasna dorade semena lucerke se ostvaruje odgovarajućom kombinacijom mašina za doradu pri čemu se dobija odgovarajući kvalitet i veća količina dorađenog semena u kraćem vremenskom periodu uz što manji utrošak energije.