Aleksandar Stanojkovic

Genetic variability of red clover seedlings in relation to salt stress.

Red clover is highly salt-sensitive plant, especially during germination and early seedling growth stages. The aim of this investigation was to estimate the effects of different saline conditions (0, 50, 100, 150, and 200mM NaCl) on germination and early seedling growth in four red clover varieties (Kolubara, K-32, K-17 and K-39). Germination test was conducted in the laboratory conditions using sterile plastic vessels on filter paper moistened with 10ml of the appropriate salt test solutions. It was observed that the germination energy (GE), germination (G), percentage of dead or infected seeds (DIS), normal seedlings (NS), root length (RL), shoot length (ShL), fresh weight (FW) and dry weight of seedling (DW) and seedling vigor index (SVI) were significantly decreased with increasing concentrations of NaCl in the growing medium. The tested varieties of red clover showed different NaCl tolerance at the seedling stage. Generally, studied red clover varieties are very sensitive to salt, especially K-32 which has the lowest values for GE, G, NS and SVI and highest for DIS. Variety K-17 proved to be a variety that the best tolerates conditions of salt stress because the values for GE, G, NS, RL and SVI were highest. Testing of varieties of red clover in the early seedling growth at different concentrations of NaCl in the growing medium could be helpful in the identification and selection of varieties for cultivation on saline soils. [Projekat Ministarstva nauke Republike Srbije, br. TR 31053]

Evaluation of Mineral and Bacterial Fertilization Influence on the Number of Microorganisms from the Nitrogen Cycle in Soil under Maize

In 2006, the influence of different rates of applied mineral fertilizers and their combinations with bacterial inoculants [nitrogen (N)–fixing Klebsiella planticola and Enterobacter spp.] on the number of microorganisms from the N cycle in a Cambisol and the yield of maize was evaluated in this study. The results obtained implied that high rates of mineral fertilizers brought about an increase in the number of fungi and a decrease in the number of Azotobacter spp., oligonitrophiles, ammonifiers, and nitrifiers in soil. Combined application of microbial inoculants and low rates of mineral fertilizers resulted in the greatest increase in the number of Azotobacter spp., oligonitrophiles, and ammonifiers in soil. The greatest number of soil nitrifiers, as well as the grain yield of maize studied, were determined in the variants where combinations of the microbial inoculants and low and high rates of mineral fertilizers were applied.

Comparative examination of the meat quality of the female cattle of Simmental breed and crosses with Charolais breed

The paper presents the results of a comparative examination of the beef quality obtained from females of two genotype groups: domestic Simmental breed (A) and its crosses with Charolais breed. The sample included a total of 20 heads, 10 in each group. Cattle were slaughtered at the same age with uniform body weights. After slaughtering, warm carcass sides were individually weighed, with and without kidney fat. After cooling, the left carcass sides were cut into the basic parts according to the Rulebook and the three-rib cut was cut off from the back part (9-10-11 rib). The content of tissues in the three-rib cut was statistically different among the groups, the content of muscle tissue was significantly higher (p <0.05) in cattle of the group (A) and the content of fat tissue was statistically (p <0.05) significantly higher in the group (B). The chemical composition of M. longissimus dorsi did not differ statistically between groups. The technological quality of the meat was evaluated through the tenderness of the M. longissimus dorsi which was statistically significantly better (p <0.05) in the cattle of the group (B) and the content of total pigments statistically (p <0.05) significantly higher in the cattle of group (B). The sensory traits of M. longissimus dorsi did not differ statistically significantly between groups.

Chemical composition and yield of maize green biomass as affected by bacterial and mineral fertilization

The purpose of the study was to evaluate the influence of an application of different rates of composite mineral fertilizers and their combination with bacterial inoculants (N-fixing Klebsiella planticola and Enterobacter spp.) on chemical composition and yield of the maize green biomass (without spikes) on acid Eutric Cambisol during the two growing seasons: 2006 and 2008. Unfertilized soil was used as a control. The contents of nitrogen, phosphorus, potassium and crude proteins in biomass samples were determined three times during the maize vegetation season, as follows: stage of intensive growth, milk-waxy maturity stage and full maturity stage. Measuring of the green biomass yield was carried out at the end of the vegetation. The results of the study showed that the use of high rates of composite mineral fertilizers and their combination with bacterial inoculants resulted in increased contents of nitrogen, phosphorus, potassium and crude proteins in the maize biomass during the both study years, which was noticeably observed in the stage of intensive growth. The highest increase in the biomass yield was obtained by the same mentioned treatments, although the combination of bacterial inoculants and lower rates of mineral fertilizers resulted in higher yields comparing to the application of lower rates of the pure mineral nutrients. The data suggest that the studied bacterial inoculants can be used in further investigations as the potential agents of new biofertilizers for improved maize production and other agriculture crops in animal nutrition.

EFFECT OF FOLIAR FERTILIZATION ON SOYBEAN GRAIN YIELD

The aim of this investigation was to estimate the effects of foliar fertilization on quantitative traits (plant height, first pod height, number of nodes per plant, number of pods per plant, number of grain per plant, grain yield per plant, 1000-grain weight and grain yield) in two soybean cultivars (Balkan and Becejka). Studied cultivars belong to different maturity groups (Balkan - I and Becejka - 0). Four treatments of fertilization were tested: control (no fertilization), Urea (46 kg N ha-1), Urea (46 kg N ha-1) + Wuxal super (5 l ha-1) and Urea (46 kg N ha-1) + Ferticare I (5 kg ha-1). Wuxal super and Ferticare I were foliar applied two times at the R2-R3 growth stage. The field experiments were carried out in dry land farming in the region of Vojvodina province at location Putinci (45° 00′ N Lat., 19° 58′ E Long.), during the years 2007 and 2008. In both research years, Balkan had higher values for all investigated traits than Becejka. Results showed that foliar fertilizers significantly increased the values for all quantitative traits. Ferticare I is more effective than Wuxal super in soybean because this fertilizer has higher concentration of macronutrients. Foliar fertilization of soybean reduced the negative impact of small amounts of rainfall during the summer months on grain yield. [Projekat Ministarstva nauke republike Srbije, br. TR 31053]

CARCASS QUALITY OF CHICKENS OF DIFFERENT CONFORMATION

The aim of this study was to investigate the effect of conformation of chickens of different genotype on the yield of breast meat. As a typical example of the chickens of very poor conformation pure breed Naked neck chickens were taken, fattened 8 and 10 weeks (groups K8 and K10). As an example of good conformation, an imported hybrid of chickens was taken, known for its broiler qualities and as medium growing hybrid, Red Bro (R). The second experiment included commercial hybrids of fast growth (Ross, Cobb and Hubbard) reared according to all technological standards of intensive fattening until the age of 42 days. The results obtained were contrary to the conclusion obtained a few decades ago, at the beginning of the study the conformation of chicken, by Scots and Darrow (1953), according to which the selection of chickens of heavy type, despite the fact that, to some extent, it had improved meat yield of the breast, did not significantly improve slaughter traits of fattening chickens, confirming that better conformation and higher body weight had a positive impact on improving relative share of breast, i.e. white meat. The results regarding the slaughter traits of chicken genotypes of different conformation suggest that breeding - selection work to improve the conformation of broilers significantly improved slaughter yields and breast meat yield. In this sense, the conformation can be treated as an indicator of the slaughter value of carcasses, rather than an aesthetic category. [Projekat Ministarstva nauke Republike Srbije, br. TR-31033]

The possibilities of intensive field crop production on the pseudogley type of soil using the complex amelioration measures.

In Republic of Serbia the pseudogley type of soil outspreads on approximately 443.000 ha or 4,7 % of the total area. At the area of West and North-West Serbia this type of soil outspreads on approximately 360.000 ha or 20% of the total area. The main characteristics of Pseudogley are unfavorable chemical properties, heavy mechanical composition, compaction and low hydraulic conductivity, which result in an unregulated water-air regime. An ameliorative action that could regulate unfavorable water regime of these soil types is the implementation of the horizontal pipe drainage. On experimental drainage field Varna near Sabac, owned by Institute of Soil Science, on the pseudogley type of soil, it was established an experiment in order to follow the effect of different spaces of the horizontal pipe drainage on increase of the yields of main crops (wheat and maize) in relation to the undrained areas. The processing of data of the realized yields in the period 2004-2009 shows that on the plots on which the pipe drainage was implemented, compared to the undrained areas, the yield of wheat increased 8-60%, while the yield maize increased 6-43%. Regarding the areas at which this type of soil outspreads, by implementation of the complex amelioration measures this potentially productive soil would enable economically profitable agricultural production, especially crops for animal food. This will increase the opportunity for intensifying animal production.