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

Silage fermentation characteristics of grass-legume mixtures harvested at two different maturity stages

The objective of our study was to investigate the diversity of individual parameters of quality of grass-legume mixture silages harvested in two stages of crop utilization and the impact of the interaction of studied factors on the quality. Legumes as an important source of protein are very difficult to ensilage. However, in mixture with grasses their fermentable characteristics are improved. During the growth and development of plants, their chemical composition changes, hence their ability and suitability for ensiling also changes. In regard to the studied factors, the phase of exploitation had a highly significant impact on almost all quality parameters in both years. By delaying the harvest period, dry matter content in silage has significantly increased and the level of crude protein and NH3-N decreased. In regard to the content of lactic acid, the studied silages fall into category of good quality silages. Its content in the first year ranged from 24.3-31.5 in the early harvest stage and from 27.9-36.2 g kg-1 DM at the late harvest stage, and in the second year from 27.4 to 31.4 in the early harvest stage and from 28.2- 31.9 g kg-1 DM at the stage of late harvest. According to the content of acetic and butyric acids, studied silages can also be considered as silages of good quality

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 Bečejka). Studied cultivars belong to different maturity groups (Balkan - I and Bečejka - 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 Bečejka. 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

Management practices effect on seed features of Italian ryegrass following storage period

Italian ryegrass seed crop was established in 2007 with two sowing densities (D1 = 60 cm row spacing and 5 kg ha-1 seeding rate; D2 = 20 cm row spacing and 20 kg ha-1 seeding rate) and using two spring nitrogen rates (0 and 150 kg N ha-1). Seed germination and thousand seed weight (TSW) of Italian ryegrass was observed in first production year. After harvest in June, seeds were stored under standard storage conditions and sampled 90 days after harvest (DAH), and then 2000 DAH. At 90 DAH, seeds were tested for TSW, as well as germination energy and total germination percentage at incubation temperatures of 10, 15, 20 and 25°C. Ryegrass seeds had the best germination energy 90 DAH at 20°C and maximum total germination at 15°C, which implies that early autumn (September-October) is proper sowing period for freshly harvested seeds of Italian ryegrass. Italian ryegrass seeds could maintain satisfactory germination energy (59.3%) and total germination (77.3%) up to 2000 DAH. High seed quality was obtained and applied treatments did not change seed quality significantly unlike storage period which had considerable influence on seed quality. The data can serve for the determination of a proper storage duration management between harvest and sowing of the tested species under ambient conditions of Serbia

Presence of deoxynivalenol in winter wheat treated with fungicides

Natural occurrence of Fusarium spp. and concentrations of mycotoxin deoxynivalenol (DON) in the grain of the winter wheat moderately susceptible to Fusarium head blight (FHB) has been studied. Grain samples were collected from wheat crops intended mainly for human consumption. All wheat crops were treated with fungicides before (a.i. flutriafol - formulated as Fluoco, applied in dose of 0.5 l ha-1) and during the flowering phase of growing (a.i. thiophanate-methyl + epoxiconazole formulated as Eskorta plus and a.i. thiophanate-methyl formulated as Funomil, applied in doses of 0.75 and 0.5 l ha-1, respectivily). Among of Fusarium species only F. graminearum, as a well known producer of DON, was identified. This fungus was identified in 15 of 19 samples (78.9%) with incidence in positive samples of 2 to 28% (average, 14.0%). Presence of DON was established in 13 of a total 19 investigated wheat grain samples (68.4%). In positive samples DON was detected in concentrations from 69 to 918 μg kg-1 (average, 478 μg kg-1). DON showed a significant and positive correlation at P≥0.05 with grain moisture content (r = 0.52*). Between the frequency of F. graminearum and concentration of DON and between the frequency of F. graminearum and grain moisture content, positive correlation was determined, but without statistical significance (r = 0.44 and r = 0.29, respectively)

The effect of crop density on yield of forage maize

The aim of this investigation was to estimate the effects of crop density on the plant height (PH), stem diameter (SD), number of leaves per plant (NL), forage yield hectare-1 (FY), dry matter yield hectare-1 (DMY), stem percentage (SP), leaf percentage (LP) and ear percentage (EP) in two maize hybrids of FAO maturity group 600 (ZP 684 and NS 6010). Field trials were carried out in rainfed farming in the Srem region (location Putinci: 44° 59' 19' North and 19° 58' 11' East) during years 2007 and 2008. Three crop densities were compared: G1 - 51,020 plants ha-1, G2 - 59,524 plants ha-1 and G3 - 71,429 plants ha-1 (corresponding to spacing of 70 × 28, 70 × 24, and 70 × 20 cm). Plots were organized as completely randomized block system design in four replications. PH (265.45 cm), SD (2.40 cm), FY (68.63 t ha-1) and DMY (24.63 t ha-1) were significantly higher in 2007 than in 2008 (261.78 cm, 2.32 cm, 61.17 t ha-1 and 21.04 t ha-1, respectively). Hybrid NS 6010 had significantly higher PH (266.23 cm), SD (2.39 cm) and NL (14.75) than hybrid ZP 684 (261.0 cm, 2.33 cm and 13.99, respectively). Increasing crop density significantly increased the PH, FY, DMY and SP, and significantly decreases the SD and EP. Therefore, crop density of 71,429 plants ha-1 (70 x 20 cm) can be recommended for growing hybrids of FAO 600 maturity group in climatic conditions of Srem in order to achieve high yields of forage and dry matter

The influence of genotype and osmotic stress on germination and seedling of maize

The aim of this research was to estimate the influence of different NaCl osmotic solutions (0, -0.3 MPa, -0.6 MPa, -0.9 MPa, -1.2 MPa, -1.5 MPa) on seed germination, and early seedling growth in two maize hybrid different maturity groups (ZP 560 - FAO 500 and ZP 666 - FAO 600). Germination was tested in sterile plastic vessels on filter paper moistened with different NaCl solutions, in the dark at 20 ± 1°C, in laboratory. Results of ANOVA indicated that hybrid ZP 666 had significantly higher root length (RL) (6.37 cm), shoot length (ShL) (2.06 cm), shoot fresh weight (ShFW) (43.86 mg), root dry weight (RDW) (7.56 mg), shoot dry weight (ShDW) (5.97 mg), seedling vigor index (SVI) (706.55) and dry matter stress tolerance index (DMSI) (55.85%) than hybrid ZP 560 (4.18 cm, 1.14 cm, 32.50 mg, 6.54 mg, 4.15 mg, 457.61 and 48.86%, respectively). Contrary, hybrid ZP 560 had significantly higher relative seedling water content (RSWC) (83.83%) and phytotoxicity of shoot (PhSh) (69.77%) than hybrid ZP 666 (81.16% and 62.51%, respectively). Generally, hybrid ZP 666 had better tolerance to salt stress than hybrid ZP 560. Germination energy (GE), germination (G), RL, ShL, root fresh weight (RFW), ShFW, RDW, ShDW, rate germination index (RGI), SVI, RSWC and DMSI were significantly decreased with the increase in osmotic stress induced by NaCl. Contrary, phytotoxicity of root (PhR) and PhSh significantly increased with the increase in osmotic stress

Natural mycobiota and aflatoxin B1 presence in bee pollen collected in Serbia

Total fungal count, incidence of fungi and aflatoxin B1 (AFB1) concentration were studied in 33 samples of bee pollen randomly collected from beekeepers in Serbia. The total number of fungi was determined by dilution method whereas AFB1 was detected using the Enzyme-Linked Immuno-Sorbent Assay (ELISA). The mycological estimation showed the presence of nine genera of fungi as followed: Acremonium, Alternaría, Aspergillus, Cladosporium, Epiccocum, Fusarium, Mucor, Pénicillium and Rhizopus, with total number ranging from 1 x 103 to 1 x 105 CFU g-1. The results have shown the predominance of the fungi from the genera Aspergillus and Alternaria. Among Aspergillus species it was observed that the most frequent species was A. flavus with incidence of 27.27 %. Mycotoxin AFB1 was detected as 100% positive in all samples (100%) with an average concentration of 8.61 μg kg-1. The obtained results indicated that honey bee pollen must be strictly controlled during its manipulation in the harvesting and manufacturing. Therefore, the implementation of good manufacturing (beekeeping) practice to define procedures for honeybee products could be crucial to reduce the risk of possible contamination and provide natural and safety product without risk on the human health

Fungal contamination and natural occurrence of ochratoxin A (OTA) in poultry feed

Total fungal count, the presence of potentially toxigenic fungi and natural occurrence of ochratoxin A (OTA) were studied in 30 poultry feed samples (14 samples of feed for chickens and 16 samples of feed for laying hens), which were collected from different farms in Serbia at the beginning of year 2014. The total number of fungi was determined by the method of dilution and OTA was detected using the imunoadsorption enzymatic assay (ELISA). In most of the samples of chickens feed (50%) the total number of fungi was 1 - 3 x 102 CFU g-1, and in feed for laying hens the highest number of samples (37.50%) had the total fungal count from 1.4 to 4.8 x 104 CFU g -1. The species of genera Aspergillus and Pénicillium were identified as producers of OTA in 21.43% and 42.86% of chickens feed samples and in 68.75% and 25% of samples of feed for laying hens. The presence of OTA was detected in 100% of samples of feed for chickens and laying hens, with average concentrations of 34.40 μg kg-1 (feed for chickens) and 43.89 μg kg-1 (feed for laying hens). The total fungal count and content of OTA were not above the maximum allowed quantities, even though the presence of Aspergillus and Penicillium species was found in a large number of samples (up to 68.75%). These results indicate that the tested samples of poultry feed were mycologically and mycotoxicologically correct

Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training

The protection of human health and the preservation of the environment are topics that form anintegral part of the primary school curriculum in Serbia. However, research studies have shown thatstudents do not have enough knowledge to contribute to the development of a healthy lifestyle andenvironmental awareness. The latest changes in school policy and curricula confirm that the relevanceof environmental education has been recognized, but changes in school practice are yet to come. Thisarticle discusses the challenges encountered in the implementation of the intended curriculum andoffers suggestions for changes to the curriculum, pedagogy, and teacher training in order to enhanceenvironmental educationThis is the peer-reviewd version of the artivle: Stanišić, Jelena, и Slavica Maksić. 2014. „Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training“. Journal of Environmental Education 45(2):118–31. doi: 10.1080/00958964.2013.829019.Related to published version: [ http://ipir.ipisr.org.rs/handle/123456789/240