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: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:V. Guberac, S. Maric, M. Bede, J. Kovacevic, G. Drezner, A. Lalic, M. Josipovic, M. Krizmanic, T. Juric and D. Kis
The aim of this research was to examine influence of sowing rate on grain yield of four new winter wheat cultivars, taking in account their genetic characters. Statistical analysis of the obtained results showed that the sowing rate influence on the grain yield was not statistically significant. On the other hand, various sowing rates had highly significant influence on the ear number per a unit area. The largest number of ears was achieved by the sowing rate of 700 germinable seeds/m
).Difference in grain yield between examined cultivars was highly significant (P<0.01) while the difference in number of ears per a unit area was significant (P<0.05). The highest average yield and highest number of ears in the two-year period were achieved by the cultivar AG 5.12 (8.56 t/ha and 770 ears/m
).Since a satisfactory and statistically significant grain yield was achieved, even with a lower sowing rate, both during and in the average of the two year research, the author’s advice wheat producers to apply the above mentioned. In this way total production costs would be decreased to a lower rate.