Authors:V. Kovačević, M. Rastija, D. Rastija, M. Josipović, and M. Šeput
Five maize (
L.) hybrids were grown for four growing seasons on gleysol characterized by moderate supply with potassium (K). Three rates of KCl were applied in four replicates at the beginning of April 2001 as follows (kg K
O/ha): 150 (control), 650 and 1400. The highest rate of KCl resulted in significant increases of yield of 14%, 24% and 12%, for 2001, 2002 and 2003, respectively; while in the fourth year similar yields to the control were found. The OsSK552 and Bc5982 hybrids (4-year mean 8.70 t/ha) were more susceptible to soil stress in comparison with OsSK444 and OsSK458 (mean 9.07 t/ha). At the same time, Florencia hybrid yielded 9.37 t/ha. Four hybrids responded similarly to applied fertilization (yield increases from 13 to 16% in comparison to the control), while Florencia had low response to KCl (yield increase for 5% only). Under these conditions we recommend combined solution using 1000 kg K
O/ha every third year and a choice of tolerant hybrids.
Authors:V. Kovacevic, D. Banaj, J. Kovacevic, A. Lalic, Z. Jurkovic, and M. Krizmanic
Aim of this study was testing of field crops (maize-maize-sunflower-winter barley rotation) to lime (carbocalk: waste of sugar factory, 39% CaO) application in five rates up to 90 t/ha. Field trial was conducted in autumn 2000 in four replicates. Liming with carbocalk resulted with considerable increases of field crop yields as follows: up to 50% and 36% (maize for 2001 and 2002, respectively), up to 49% (sunflower 2003) and up to 30% (barley 2004). In general, by application of carbocalk to level of 90 t/ha, yields drastically decreased mainly to level of control as affected by over liming. Concerning oil contents in sunflower grain, it was significantly higher compared to control for treatments 15, 30 and 45 t/ha, but similar for control and 60 t/ha. Using of 45 and more lime per hectare decreased grain quality of malting barley because protein contents were significantly increased.
Authors:M. Banović, B. Miličević, K. Kovačević Ganić, and D. Komes
The prospects of quality young wine distillates production have been examined. The base wine was produced from Vitis vinifera L. quantitatively dominating grape varieties within the group of the recommended and permitted varieties of Kutjevo vineyards, located in the eastern part of the continental Croatia. Characterisation of wine and distillates was based on chemical and instrumental methods and on their sensory evaluation. Volatile compounds were analysed and identified by GC-FID and GC-MS. The wine varieties Rhine Riesling, Müller Thurgau and Riesling have the potential for the production of quality distillates, suitable for maturation. Pinot White, Traminer and Chardonnay give more acceptable wines than distillates and it is therefore not advisable to use them for distillates production, while the varieties Pinot Gris, Frankovka and Steinschiller are not suitable for the production of distillates.
Authors:D. Banaj, V. Kovacevic, D. Simic, M. Seput, and B. Stojic
The field experiment with three rates of phosphorus (P) fertilization for maize (OsSK444 and OsSK552 hybrids) up to 2000 kg P
/ha were conducted in the spring 2002. For the next growing seasons (2003 and 2004) only ordinary fertilization was applied. In general, maize yields were independent on applied fertilization. Only application of the highest P rate had residual influences on maize yields for the 2003 growing season. Probably very favorable weather conditions for 2002 and 2004 could be responsible factor for low influences of fertilization on maize yields. Also, maize hybrid OsSK552 yielded more than OsSK444. The ear-leaf of maize at beginning of silking (the 2002 growing season only) was taken for chemical analysis. Leaf P, Mg, Mn and Fe concentrations increased by application of the highest rate of P. At the same time, K, Ca, Zn, Cu and Fe concentrations significantly decreased. Especially influences of P fertilization were found for Zn status in maize leaves (70 and 40 ppm Zn, for the control and 2000 kg P
/ha, respectively). OsSK552 hybrid characterized by the higher K, Ca, Mg, Cu and Fe, as well as the lower Zn concentrations in comparison with the OsSK444 hybrid.
Authors:G. Boskovic, A. Zarubica, M. Kovacevic, and P. Putanov
Properties of two catalysts tailored in the laboratory conditions by sulfation of commercial Zr-hydroxide and Zr-hydroxide
of nitrate origin were compared with those of commercial SO4-Zr-hydroxide. Equally thermally treated samples in the temperature interval 500–700°C, and having the same amount of sulfur,
show different properties indicating memory effect of their solid parent materials. The catalyst obtained by sulfation of
commercial Zr-hydroxide differs in amount of residual sulfates upon calcination from other two catalysts. The instability
of sulfates in the previous case might be connected to the lowest surface area values of catalyst and the highest fraction
of monoclinic phase observed at all applied calcination temperatures.
Authors:M. Rastija, V. Kovacevic, D. Rastija, and D. Simic
Drought and soil acidity are two major abiotic stress factors limiting maize production worldwide, generating imbalances in the manganese (Mn) and zinc (Zn) status in plants. This study was conducted to determine the effects of drought stress on the Mn and Zn status in maize genotypes grown on acid and non-acid soils and how the Mn and Zn status affects the changes in grain yield caused by drought stress and soil acidity. Seventeen genotypes were grown at two locations differing in soil acidity in Eastern Croatia in 2003 and 2004. Positive values of an aridity index indicated drought stress in 2003. The genotypes had much higher Mn and Zn concentrations on acid soil than on nonacid soil: more than twice as high in both seasons for Zn and about 6 and 9 times higher in normal and in dry seasons, respectively, for Mn. This demonstrates that drought combined with soil acidity led to the excessive accumulation of Mn in maize plants. However, variation was observed between the maize genotypes for the Mn accumulation on soils differing in acidity when drought occurred. Some genotypes accumulated Mn on acid soil irrespective of drought. The Mn and Zn status had no discernible effect on the changes in grain yield caused by drought stress and/or soil acidity.
Authors:M. Marković, P. Pepó, M. Sárvári, V. Kovačević, J. Šoštarić, and M. Josipović
In the decade from 2000 to 2009, the yield of maize grain in Croatia varied from 4.2 t ha−1 (2003) to 8.0 t ha−1 (2008). The yield variation was mainly caused by weather conditions unfavourable for maize production, meaning lack of precipitation, unevenly distributed during the vegetation season, and mean air temperatures above the long-term mean. Irrigation has become a justified and essential agrotechnical measure that minimizes the damage caused by water deficit during critical plant growth stages and ensures high yields with good quality. In this paper two vegetation seasons (2006 and 2007) with quite different weather conditions for maize production were analysed in order to examine the importance of irrigation in terms of yield increase, irrigation water use efficiency (IWUE), irrigation efficiency (IE) and irrigation water use index (IWUI) in years favourable (2006) or too dry (2007) for maize production. The yield surpluses achieved with irrigation ranged from 8.54 t ha−1 to 9.62 t ha−1 in the average crop year (2006) and from 8.43 t ha−1 to 10.7 t ha−1 in the dry year (2007), depending on the irrigation method. In the dry year the values of IWUE where higher than in the average year (6.16 and 13.75 kg ha−1/mm, respectively, averaged over the hybrids).
Authors:I. Liović, A. Mijić, M. Krizmanić, P. Pepó, V. Kovačević, A. Markulj, T. Duvnjak, and G. Krizmanić
Environmental conditions (soil, weather) have the greatest impact on the production of all crops, so it is necessary to check the behaviour of new hybrid combinations under diverse environmental conditions. In 2009 and 2010, field trials were sown at various locations in Croatia to test new sunflower hybrid combinations bred at the Agricultural Institute in Osijek. In both years, the trials were conducted in Beli Manastir (BM09 and BM10), Nova Gradiška (NG09 and NG10) and Osijek (Os09 and Os10), while in 2010, a trial was also sown in Vukovar (Vu10). The genotypes included three cytoplasmic male sterile lines (cms 1–3) as female parent with a set of 8 fertility restorer lines (four branching restorers: oG1–4 and four single-headed restorers: oM5–8). The grain yield data were processed for years and locations (7 environments) using analysis of variance (ANOVA) and Additive Main effects and Multiplicative Interactions (AMMI) analysis with the SAS for Windows 9.1 statistical software. To obtain a better picture of the grain yield stability of the hybrid combinations in different environments, AMMI1 and AMMI2 biplots were made using IRRISTAT for Windows 5.0 software. No significant differences were found between the hybrid combinations of the female lines (cms 1–3). Among the environments, the significantly highest grain yield was recorded in the environment Os09 (4.220 t ha−1), followed by BM09 and Os10. As regards the restorers the highest grain yields (statistically on par with each other) were found for hybrid combinations involving oG2 and oM7 (3.726 and 3.666 t ha−1). Together, the first two interaction principle components (IPC) explained 85.4, 76.6 and 64.8% of the variability for crosses involving cms1, cms2 and cms3, respectively. The AMMI1 and AMMI2 biplots showed that the highest yielding hybrid combinations did not have the most stable grain yield. The greatest stability was shown by restorer line oM7 in cross combinations with inbred lines cms1 and cms2, while the same restorer line exhibited a large genotype × environment interaction and low stability when crossed with cms3.
Authors:Tijana B. Kovačević, Slavica S. Borković, S. Z. Pavlović, R. M. Radojičić, and Zorica S. Saičić
We examined the concentrations of vitamin E (vit E), sulphydryl groups (-SH), total protein and protein electrophoretic profiles in the hepatopancreas, the gills and muscle of three freshwater crayfish species: Noble crayfish (Astacus astacus), stone crayfish (Austropotamobius torrentium) and spiny cheek crayfish (Orconectes limosus). Vit E concentration in the hepatopancreas of O. limosus was lower compared to A. astacus, while in the gills of O. limosus it was lower compared to both A. astacus and A. torrentium. The concentration of -SH groups was lower in the hepatopancreas of A. astacus compared to A. torrentium and O. limosus. In the gills of A. astacus and A. torrentium the concentration of -SH groups was higher compared to O. limosus. Protein concentration was higher in the hepatopancreas of A. torrentium compared to A. astacus and O. limosus. A lower protein concentration in muscle of A. torrentium was found compared to O. limosus and A. astacus. Electrophoretic analysis of proteins indicated species and tissue specifities between investigated crayfish species. Our results represent the first study of its kind and provide the basis for future studies that will consider our reported parameters as potential biomarkers for biomonitoring of basic environmental conditions and some anthropogenic impacts.
Authors:M. Drobac, J. Arsenijević, and N. Kovačević
Cinnamon bark is used worldwide due to its characteristic flavour and medicinal properties. Ceylon cinnamon or “true” cinnamon bark refers to the dried inner bark of the shoots of Cinnamomum verum J. Presl, originated from Sri Lanka. The bark of some other species of this genus, Cinnamomum cassia Blume (Chinese cinnamon), C. burmanni (Nees & T. Nees) Blume (Indonesian cinnamon), and C. loureiroi Nees (Saigon cinnamon) are also marketed and sold as cinnamon. They are characterised by a significantly higher amount of coumarin compared to Ceylon cinnamon bark. Since coumarin may be potentially hepatotoxic, the aim of this study was to determine coumarin level in commercial samples of cinnamon bark and in cinnamon-containing dietary supplements present on the Serbian market. HPLC analysis showed lowest coumarin content in Ceylon cinnamon bark samples (0.08-0.15 mg g-1), whereas other samples contained a significantly higher amounts of coumarin (1.38-5.80 mg g-1). Cinnamon based dietary supplements contained 0.007-1.19 mg coumarin/tablet. The obtained results indicate that the majority of commercial samples of cinnamon bark on the Serbian market do not originate from the Ceylon cinnamon but from other species of this genus, and that consumed amount of certain products should be taken into account since the tolerable daily intake of coumarin is limited.