Showing papers in "Journal of Agricultural Sciences, Belgrade in 2005"

Characteristics and composition of melon seed oil

Abstract: Dried melon seeds (Citrullus colocynthis L) of the family Cucurbitaceae were investigated for nutritional quality and the oil seed characteristics These melon seeds, on a dry weight basis, consisted of 523% of test and 477% of kernel The moisture content in melon seeds was 545% and the mineral constituents were also determined The oil content of seeds was very high ranging from 221-535%, due to the presence of the hulls, 22% from the seeds and 53% of the kernel, and also the crude protein content was so high as the 218% of the seeds Standard procedures were applied to determine the fatty acids composition of the seed oil The fatty acid profiles of the seed oil showed an unsaturated fatty acid content of 774% and the high content of 632% of PUFA The predominant fatty acid was linoleic (18:2) acid in 622% The presence of other fatty acids ranged in 10-14% for oleic (18:1) stearic (18:0) and palmitic (16:0) acids, respectively Furthermore, the physical and chemical characteristics of the seed oil was also determined as iodine, acid, saponification, peroxide values and specific gravity

Importance of phenological observations and predictions in agriculture

Abstract: Phenology can contribute to many scientific disciplines from climate change, biodiversity, agriculture and forestry to human health. The knowledge of timing of phenological events and their variability can provide valuable data for planning, organizing and timely execution of certain standard and special (preventive and protective) agricultural activities that require advanced information on the dates of specific stages of crop development. Mathematical models are the basic tools to predict the timing of phenological events. There are two types of phenological models: physiologically-based and statistical. Most of the existing models are statistical and serve to predict the onset of different phenophases according to the air temperature. These models are site- and species-specific and cannot be applied to a wide range of species and climatic conditions.

Possibilities for methanol content reduction in plum brandy

Abstract: Several methods for reducing the methanol content of plum brandies were tried: possibilities for its reduced forming during fruit must alcohol fermentation, and employing effective and rational methods in order to decrease the already existing amount of methanol by applying demethanolization column. Apart from numerous valued components, plum brandy also contains some undesirable ingredients, among which methanol has a special place. It appears during hydrolysis of pectin substances under the influence of the specific pectolytic enzymes, pectyn-methyl-esterasis in particular. A certain amount still has to be present in natural brandies in order to maintain the authentic fruit origin. Reduction of the existing methanol amounts by applying demethanolization column was most effective and came to 43-77% in comparison to the starting amount.

Effects of some production factors on chemical composition and sensory qualities of Williams pear brandy

Abstract: Pear is one of the most widely grown fruit species across the world, but of all varieties, the best and most appreciated is for sure Williams pear or Bartlett pear as better known in the West. Those choosy worldwide have been enchanted over decades and centuries by its generous, exuberant and extraordinarily pleasing aroma. Bartlett pear’s qualities are probably best expressed through its far and wide famous, delicious, of the same name, pear brandy. For many people it is a queen of all fruit brandies, while for others it is, in general, the best strong alcoholic drink. However, Williams pear brandy is scarcely present in foreign, particularly domestic, professional and scientific literature. This is the reason why the present paper’s author wants to pay due respect to Williams pear brandy for sensory pleasure it affords. Production of top quality Williams pear brandy (top quality only because it is what this pear deserves) is neither simple nor easy. The present paper deals with the most important stages of pear brandy production, therefore it is a pioneering attempt to acquaint scientific, professional and broader consumer audience with this top quality brandy.

Combining abilities of silage maize grain yield

Abstract: The aim of the present study was to evaluate the following parameters of maize grain yield: variability of inbred lines and their diallel hybrids, superior-parent heterosis and general and special combining abilities. According to obtained results of the two-year study, it can be concluded that variability of this trait is significantly affected by a genotype, year and their interaction. As expected,hybrids had higher average grain yields than inbreds due to the depression of this trait that occurs in inbreds during inbreeding. The highest average value of heterosis for gain yield was detected in the hybrid ZPLB405 x ZPLB406 (123.0% and 178.1% in 1997 and 1998, respectively). The estimation of combining abilities was done on the basis of diallel hybrids after the method established by Griffing, 1956, (method II, mathematical model I). The analysis of variance of combining ability for grain yield indicated highly significant values of GCA and SCA for the observed trait in both study years. Grain yield inheritance was more affected by non-additive genes (dominance and epistasis) as indicated by the GCA to SCA ratio that was smaller than unity. The inbreds ZPLB401 and ZPLB406 had high GCA effects, while the hybrid combinations ZPLB401 x ZPLB402, ZPLB401 x ZPLB403, ZPLB401 x ZPLB405, ZPLB402 x ZPLB406, ZPLB403 x ZPLB406, ZPLB404 x ZPLB406, ZPLB405 x ZPLB406 had high SCA effects in both study years. These hybrid combinations include one parent with high GCA effects and other with low GCA effects. Furthermore, there are combinations ZPLB402 x ZPLB405, ZPLB403 x ZPLB405 and ZPLB404 x ZPLB405 with significant SCA effects that include parents with low GCA effects. This is probably the result of the additive type (additive x additive) of interaction between parents

A chaotic economic growth model and the agricultural share of an output

Abstract: The agricultural share of a total output generally declines in the process of economic growth. The major reason for this is that consumer demand for food increases only slightly with rising incomes. However, a small, open economy can overcome this constraint to the growth of agricultural production by expanding its net exports. The basic aim of this paper is to set up a chaotic growth model of the gross domestic product that is capable of generating stable equilibria, cycles, or chaos depending on parameter values.

Effects of different substrates on basil seedlings quality (Ocimum basilicum L.)

Abstract: In this study five different substrates were used, such as: compost; mixture of compost, Lumbrikus H and garden soil; mixture of compost and Lumbrikus H; mixture of compost, Lumbrikus H and peat Galicina and Seedling Klassman substrate. Basil seedling was produced in containers according to "speeding" system. The studies have shown that the best quality of basil seedling of varieties Genovese and Lattuga is achieved when the mixture of substrates Compost, Lumbrikus H and Galicina peat are applied in the volume proportion of 50% : 30% : 20%.

Application of microbiological fertilizers in viticulture: Grape yield and quality of wine cv. Riesling

Abstract: The recommended cultivars for top quality wines Riesling in the vineyards of Grocka is in full crop. It was grafted on Kober 5 BB stock and planted on the soil type cambysoil. The content of total nitrogen is 0.1-0.15%. Supply of easily available potassium varies between 12.3-15 mg/100g a.d.s.2, i.e. phosphorus 0.4-3.6 mg/100g a.d.s. in layer up to 40 cm. Microbiological fertilizer was used in the study - biological preparation prepared with mixed natural populations Azotobacter chroococcum, Bacillus megaterium and Bacillus circulons. The space in row is idle land and the space between rows was sown each year (March-April) with a mixture of field pea and barley and ploughed in the inflorescence phase of legumes. Grape yield varied between 8772-6804 kg/ha. Microbiological fertilizer with Azotobacter had the highest yield and the control treatment had the lowest yield, where only grass mixture was sown. Extremely dry climatic conditions in the trial period caused the grape yield in cv. Riesling to be extremely low. In combination of fertilizers Bacillus megaterium + Bacillus circulons wine with the most ethanol, extracts and polyphenols was obtained. The wine obtained from the control treatment had a typical taste.

Analysis of drying potato kinetics in laboratory conditions

Abstract: Chemistry is in its nature a fundamental science, but nowadays its results are increasingly used in practice. In such a way, many syntheses of important nutrition and industrial compounds (chemical technology), or destruction of harmful substances (chemical ecology) have been developed. The analytic part of chemistry (analytical chemistry) has found a significant usage even in optimization of technological processes of food technology. One of the oldest ways of food preservation is drying (dehydration). The basis of this process of preservation is to vaporize water, to dry enough the product, in order to stop the activity of enzymes and possibility of microorganisms’ development. Water in agricultural products is not free but bound to dry matter. Therefore, for its vaporizing it is necessary to bring enough heat. The part of the brought heat is used for vaporizing water, but one part of it becomes the energy for activation of several chemical reactions that decrease the nutritive values and the quality of future food. Therefore, the important engineering problem emerges: determination of optimal conditions for drying. For optimization of technological process of drying, it is necessary to do mathematical modeling of dependence of water vaporizing speed from environmental conditions beforehand. The aim of this paper is to determine potato pieces drying kinetics in laboratory dryer, in order to determine the optimal conditions for its industrial dehydration. It was established that in the first quarter of the time of drying evaporated 28.3% of total evaporation of water, and then in order by quarters: 53%, 14.1% and 4.6%, respectively. The greatest speed of drying was realized at moisture of potatoes about 50%.

Terminology used in sensory evaluation of plum brandy šljivovica quality

Abstract: Sensory evaluation of sljivovica quality is a demanding and responsible task To carry out the evaluation satisfactorily, certain specific conditions must be fulfilled. To clearly define all necessary sensory characteristics of sljivovica, an official vocabulary of professional terms and concepts should be established in both theory and practice. The development of an official vocabulary is becoming an imperative, especially when it is evident that subjectively uttered words and concepts and their use can lead to lack of understanding or misunderstanding. The motivation for initiating work on such vocabulary derives from the fact that all renowned world drinks like Cognac, Calvados, Whisky etc have had it for a long time, while Serbian sljivovica has never had it. Due to the lack of an official professional vocabulary, and for the needs of the present paper, the author has taken liberty to present to the research and professional public the vocabulary he has compiled for sensory description of basic parameters of plum brandy sljivovica quality. The vocabulary comes from personal experience and participation in numerous official commissions for evaluating the quality of alcoholic drinks and wines in Yugoslavia. The proposed terms for the plum brandy sljivovica vocabulary or dictionary should be taken as a pioneering attempt and initiative for compiling a more comprehensive Serbian plum brandy dictionary. The author strongly believes that a committee of experts would be able to fulfill the task in the best possible way.

Drying of the aqueous extract of acorn Quercus robur in a spout-fluid bed

Abstract: The results of the chemical investigations of variously treated acorn samples are presented in this paper with the aim of obtaining data on the amount of nutritious components and biologically active substances. The Quercus robur acorn, which belongs to the Fagaceae family, was investigated in a raw, thermally treated form and as an extract that was subsequently dried in a dryer with a fluidized bed. The obtained results regarding the content of tannin, nitrogen containing compounds, macro- and microelements indicate that acorn maintains its functional characteristics after the investigated treatments.

Effect of greenhouse conditions on Zn, Fe and Cu content in tomato fruits

Abstract: Tomato investigations were carried out under greenhouse and field conditions. The aim was to determine the extent to which greenhouse conditions influence the chemical composition of tomato fruits. Plants grown under field conditions were used as the control. Tomato trials were performed during different periods. Greenhouse trials were carried out in the winter and the spring period (January-June), and field trials in the spring and the summer period (May-September). Zinc (Zn), iron (Fe) and copper (Cu) content was established in ripe tomato fruits. Greenhouse conditions were found to effect zinc and iron content in tomato, whereas copper content was unaltered.

Effect of the use of synthetic sound during incubation in chicken

Abstract: In the present work the effect of the use of synthetic sound during incubation in chicken of the Hampshire breed was studied. For the stimulation, an electronic sound generator with amplitude of power 1250 mV and time interval of 134 ms, 176 ms, 210 ms and 380 ms was used. The study was carried out in three experiments. In the 1 st experiment we tried to determine the influence of sound stimulation on the hatching of chickens from egg set of the variant of weight. In the 2 nd experiment we tried to determine the influence of the variant of the beginning of sound stimulation on chicken hatching. In the 3 rd experiment we tried to determine the influence of sound stimulation with constant amplitude of power and the variant of the time interval on chicken hatching. The most suitable eggs to be used for the stimulation with synthetic sound are the ones with the weight of 58.0-60.0g. In this weight category, the chickens hatched earliest of all the groups and there was no decrease in hatchability either. In order to achieve an earlier beginning of beak clapping, a faster whole group beak clapping time, and a shorter hatching time of chickens, sound stimulation should begin at the 433 rd hour of hatching. At the constant amplitude of power of the stimulating sound, the earliest hatching was observed when the time interval was 176 ms. Less suitable for stimulation are the time intervals 134 ms and 380 ms.

Effects of the use of formic acid in different doses as the conserving in Lucerne ensiling

Abstract: The influence of formic acid added in three doses (3,5 and 7 g/kg fresh mass) in the intensity of proteolysis and fermentation in Lucerne silages was investigated. On the basis of chemical analyses, it is observed that with the increase of conserving dose the lower pH value, limited proteolysis and increased preservation of proteins was achieved. The amino acid content varied very much due to their degradation and biosynthesis. In treated silages a statistically significant increase of lactic acid was observed while silages with maximum dose of conserving had significantly less free and total acetic acid. Presence of bonded butyric acid only in the control silage had no statistical significance. According to Dulphy and Demarquilly (1981) method, control silage with minimum dose of conserving was estimated as III class and silages with medium and high dose of formic acid were estimated as II quality class.

Conservation of soil moisture in deep tillage rigosol under wheat and maize

Abstract: At the experimental field "Radmilovac" of the Faculty of Agriculture of the University of Belgrade the study of the conservation of soil moisture in deep tillage Rigosol was carried out. The so called type of soil Rigosol was covered by wheat and maize. The Rigosol was formed by special treatment of the parent soil the Eutric Cambisol. The researches have been conducted during the most important phenophases of the crop growth, including formation of kernels, flowering, fertilization, grain filling and maturity. Special attention was paid to the measurements of soil moisture in the period when crop water requirements are the greatest. The conservation of the soil moisture was observed along the vertical profiles of soil. The following parameters were monitored: time intervals without rainfall, precipitation rate and the rate of crop phenophase development. Very favorable soil moisture conservation was observed, both for wheat and maize covered soil. The greatest content of soil moisture was measured at the depths from 10 to 30 cm, in the zone of crop roots. As the consequence, the favorable conditions for crop growth and yields were observed. Deep tillage of soil had positive effects on homogeneous distribution of soil moisture along the vertical profile, independently of the crop type. It was shown that the Rigosol ensures better conservation of the soil moisture than the parent soil (Eutric Cambisol), if all agriculture measures are applied in the proper time.

Impact of additives on corrosion rate of cans filled with pieces of apricot

Abstract: Polarization techniques are used for testing the impact of different compounds (additives) on tinplate corrosion, using pieces of apricot dipped in syrup with and without nitrate addition as electrolyte solution, at the same time using filled cans as electrolytic cell and operating electrode. This procedure determined the intensity of inhibiting tin dissolving with some of the used additives like sodium-benzoate, potassium-sorbate sodium-lauril-sulphate and p-aminobenzoate acid. Adding these additives to canned pieces of apricot in syrup led to inhibiting of tin dissolving, which was experimentally proved.

Changes in leaf water status in grapevine graftlings treated with growth regulators

Abstract: The effect of foliar application of plant growth regulators, paclobutrazol (1000 mg/L), chlorcholine chloride (200 mg/L) and gibberellic acid (100 mg/L) on leaf water status in grapevine graftlings of cv Cardinal was investigated After stratification and waxing, young vines were planted into vegetation pots and grown in a glasshouse Foliar treatments were applied once, twice or three times during the vegetative period, starting on 25 July and every 15 days thereafter Values of total water potential (Tl) and of relative water content (RWC) were measured over the same period Results indicate a tendency of increased TL values in leaves of plants repeatedly treated with a growth inhibitor paclobutrazol (-118 Mpa) compared with untreated (-136 Mpa) as well as plants treated twice with gibberellic acid (-137 Mpa) RWC in leaves was significantly increased in the second half of the vegetative period when paclobutrazol was applied twice (78%) in comparison with control (75%) Values of both investigated indices point to a more favorable water status of plants treated during the vegetative period with growth inhibitors compared with untreated and plants treated with gibberellic acid

Plasticity of pseudogley soils in Ub community

Abstract: The paper includes the results of determination of Atterberg plasticity limits of arable (0-25 cm) and subarable (25-50 cm) horizons in 53 pseudogley profiles from the community of Ub. On the basis of performed laboratory investigations, it has been found that the pseudogley belongs to the group of moderately plastic soils, with plasticity index higher than 17. In the arable horizon, average moisture at the plastic limit is about 20 %, and in the subarable horizon - about 19 %. Average values of the liquid limit in the arable horizon are about 38 %, and in the subarable horizon about 40 %. The optimal moisture for machine tillage of the investigated pseudogley and for other field operations varies between 19 and 22 %. Several other physical and textural characteristics are presented, including clay activity index and potential mechanical instability and soil susceptibility to treading.

Possibility of growing elecampane in conditions of non-watering field crop production

Abstract: Intensively researching different populations of elecampane, we are able to present the results of yield achieved during three years' microexperiments (2001, 2002, 2003) realized in non-watering field crop production. Comparing the results of yield, it was concluded that all five populations had higher yield, both fresh and dry elecampane root mass, compared to standard cultivars called "Domaca". The highest yield of 28,617 kg ha"1 of fresh, and 8,301 kg ha"1 of dry root had the population "NS", and it was more than standard. Considerable results were achieved by the population "SŽ" (77 % higher yield of fresh mass, and 70 % of dry mass), also the population "BM " (62 % higher yield of fresh mass, and 84 % of dry mass). The lowest yield had the population "SG" and standard cultivars "Domaca", mostly because of late planting in the second study year.

Some properties of Guyon's method for drain spacing determination on the marshy gley soil

Abstract: The aim of this work is to show out some properties of Guyon's method for drain spacing determination in unsteady state of flow. The analysis has been carried out in the marshy gley soil of the experimental field with drain spacing of 10 m, 20 m and 30 m. The method assumed modeled dynamics of water recharge, which hasn't been observed during the experimental trial. Therefore, its application is limited.

Effects of agricultural policy on the development of Slovenian agriculture during the transition and the process of accession to the European Union

Abstract: The thesis analyzes the development of agricultural policy and agriculture in Slovenia in the period from 1992 to 2002. The analysis is based on the classification of agricultural policy and its measures, standard indicators used for analysis of development of agricultural policy and agriculture, and specific methods for evaluating the efficiency of agricultural policy (evaluation methods, simulation methods). The results show that the transition in Slovenia caused no marked shocks for agricultural production. The development goals for agriculture were set forth early (in 1992) and were modeled on the EU standards, and they remained unchanged throughout the transition. A protectionist development concept of agricultural policy was adopted, which assured a relatively high level of support to agriculture. Under this concept, the agricultural policy was substantially reoriented during the transition, but this happened gradually and was reflected above all in the re-instrumentation of policy and changes of the structure of support to agriculture. Agricultural policy was relatively successful. It managed to achieve most of the strategic development goals of agriculture and a high degree of compatibility with the Common Agricultural Policy (CAP).