Variability of dry substance accumulation and utilization parameters of Winter wheat plant

Some dry substance accumulation and utilization parameters of wheat plant and their influence on grain yield have been studied through a field trial with 20 winter wheat cultivars. The studied parameters value (biological yield dry substance reutilization, number of grains per spike, 1000 grain mass plant height, etc) varried depending of genotypic specificity and environmental conditions. Grain yield was influenced not only by the total dry substance accumulation in plant (i.e. biological yield), but also by this accumulation amount before and after flowering. Yield forming was affected by many parameters, and cultivar range was different for various parameters. The best grain yield was observed in cultivars having elevated values of more than few parameters. The highest mean grain yield was observed in cultivar Tina, and also high grain yield values were found in cultivars Gruža Nevesinjka, and Toplica

Productivity of some winter wheat genotypes

Yields given by different genotypes are affected by many factors, but mostly by genotype, climatic conditions and applied growing practice. Therefore, the aim of this study was to establish productivity of many winter wheat genotypes in southern Serbia, through macro-trials. The results showed the difference of grain yield mean between the investigated seasons, and that difference amounted about 1300 kg/ha. The average yield was the highest in cultivars Toplica, Stamena, Evropa, NS-rana 5, and Renesansa. The lowest grain yield was given by cultivars Tina, Sara, Sreća, and Mina

THE INFLUENCE OF CLIMATE CONDITIONS ON MAIZE YIELD IN THE SOUTHEREN PART OF SERBIA

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

Rezultati ispitivanja ratarskih prskalica u uslovima centralne Srbije

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 influence of climate conditions on maize yield in the southern part of Serbia

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

Optimizacija proizvodnje biodizela kukuruznog ulja metanolizom katalizovanom pepelom kurdeljke

The use of low-cost or priceless feedstocks such as byproducts in biodiesel production results in a reduced overall process costs. The present paper reports the use of corn germs and corn cobs as byproducts from corn-based starch production in the biodiesel production by the methanolysis of the oil extracted from corn germs, catalyzed by the ash produced by combustion of corn cobs. The major aim was to optimize the methanol-to-oil molar ratio, catalyst loading, and reaction time in a batch stirred reactor with respect to the content of methyl ester fatty acids (FAME). The statistical modeling and optimization were carried out using a second-order polynomial (quadratic) model developed by the response surface methodology combined with a 33 factorial design with 3 central points. The FAME content was determined by a high-pressure liquid chromatography method. The analysis of variance showed that only the catalyst amount, the reaction time, the catalyst amount interaction with reaction time and all three quadratic terms were the significant model terms with the confidence level of 95 %. The optimum reaction conditions (the catalyst amounts of 19.8 %, the methanol-to-oil molar ratio of 9.4 mol/mol and the reaction time of 31 min) provided the FAME content of 98.1 %, which was in an excellent agreement with the predicted FAME content (98.4 %). Thus, both corn germs and corn cobs may be suitable feedstocks for biodiesel production.Upotreba jeftinih ili bezvrednih sirovina, kao što su sporedni proizvodi, u proizvodnji biodizela ima za rezultat smanjene ukupne troškove procesa. U ovom radu su prikazani rezultati upotrebe kukuruznih klica i okrunjenog kukuruznog klipa (kurdeljke, krudeljke) kao sporednih proizvoda iz proizvodnje kukuruznog skroba u proizvodnji biodizela metanolizom ulja izdvojenog iz kukuruznih klica, katalizovane pepelom dobijenim sagorevanjem kurdeljke. Glavni cilj je bila optimizacija molskog odnosa metanol-ulje, količine katalizatora i reakcionog vremena u šaržnom reaktoru sa mešanjem u odnosu na sadržaj metilestra masnih kiselina (MEMK). Statističko modelovanje i optimizacija izvršeni su korišćenjem kvadratnog modela, razvijenog metodologijom odzivne površine, u kombinaciji sa 33 faktorijelnim planom sa 3 centralne tačke. Sadržaj MEMK-a je određen metodom tečne hromatografije pod visokim pritiskom. Analiza varijanse je pokazala da su samo uticaji količine katalizatora, reakcionog vremena, interakcije količine katalizatora sa reakcionim vremenom i sva tri kvadratna člana statistički značajni sa nivoom pouzdanosti od 95 %. Pod optimalnim reakcionim uslovima (količina katalizatora 19,8 %, molski odnos metanol/ulje 9,4 mol/mol i reakciono vreme 31 min) dobijen je sadržaj MEMK-a od 98,1 %, koji se slaže sa predviđenim sadržajem MEMK-a (98,4 %). Prema tome, i kukuruzne klice i kurdeljka mogu biti pogodne sirovine za proizvodnju biodizela

The influence of row spacing on seed yield, yield components and seed quality of alfalfa

In order to determine the influence row spacing has on yield, yield components and the quality of alfalfa in agro-ecological conditions of south Serbia, a three year long research has been conducted, testing the NS Novosadjanka H-11 cultivar of alfalfa. The average seed yield of alfalfa was highest at a row spacing of 40 cm (311.03 kg ha-1), followed by row spacings of 20 cm (286.48 kg ha-1) and 60 cm (264.83 kg ha-1). The highest and lowest number of inflorescences per stem were obtained in rows spaced 60 cm (14.39 inflorescences/stem) and 20 cm apart (9.94 inflorescences/stem), respectively. The widest row spacing of 60 cm (8.14 pods/inflorescence) resulted in the highest number of pods per inflorescence, whereas the lowest number was produced at 20 cm spacing (5.96 pods/inflorescence). Grain number per pod ranged from 3.64 (at 20 cm row spacing) to 4.18 (at 60 cm). The highest quality of alfalfa seed during the three years of research was obtained at the widest row spacing (60 cm). Thousand-seed weight was highest at 60 cm and lowest at 20 cm (2.05 g and 1.99 g, respectively). The highest average values for seed germination rate were reported for 60 cm row spacing (86.92%) and the lowest for 20 cm row spacing (83.83 %)

Influence of different nutrition systems on yield and other parameters of productivity of potato

In this paper results of studies of the effects of different combinations of mineral fertilizers and rotted farmyard manure on yield and other parameters of the productivity of potato are presented. The experiments were conducted in 2008 and 2009 in mountainous regions of Montenegro (Kolašin), on the alluvial-diluvial soil, at an altitude of about 900 m. The results obtained suggested that the application of manure had significant impact on increasing the productivity of the studied parameters of potato. The influence of mineral nutrition was also very distinct. The highest values of the studied parameters of potato productivity were obtained by applying fertilizers with humic acids (NPK 15:15:15 400 kg.ha-1 + MCB 300 kg.ha-1 and MCB 800 kg.ha-1 + KMg 100 kg.ha-1), which were, compared to the other treatments, statistically justified. The highest number, average weight and tuber yield in two years studied was obtained in the variant treated individually with MCB 800 kg.ha-1 + KMg 100 kg.ha-1 or the same variant combined with the manure. In all variants application of combination of organic and mineral fertilizers resulted in higher number and average weight of tubers, as well as the higher yield per hectare compared to the non-fertilized variant

The Influence of Row Spacing on Yield and Quality Levels of Sainfoin (Onobrychis viciifolia Scop.) Seed in Agroecological Conditions of South Serbia

In agroecological conditions of South Serbia, the influence that row spacing has on sainfoin seeds yield and quality was examined. The Makedonka cultivar was sown at the row spacing of 20,40 and 60 cm. The three year average seed yield of 483.5 kg ha-1 was made. The first year yielded the lowest (256.1 kg ha-1), whereas the highest was in the third and last year of research (649.0 kg ha-1). With respect to the row spacing, the highest yields were achieved at 40 cm (514.3 kg ha-1), and the lowest at 20 cm (428.7 kg ha-1). The row spacing had a significant effect on the quality of the seed. The highest germination energy (86.7%), seed germination (90.4%), 1000 kernel weight (25.2 g), along with the lowest hard share of hard kernels (3.5 %) were obtained at 60 cm of row spacing