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The field experiment with three rates of phosphorus (P) fertilization for maize (OsSK444 and OsSK552 hybrids) up to 2000 kg P 2 O 5 /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 2 O 5 /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.
Influences of irrigation rates and N fertilization on soybean grain yield and N leaching were tested under field conditions on Osijek, during the growing seasons 2001, 2003 and 2005 (A). The irrigation started on level of 80% field water capacity, A1 (FWC) and at level of 65% FWC, A2 and irrigate up to FWC, and non-irrigated, A3. Increased rates of N: 0, B1; 100, B2 and 200 kg N ha −1 , B3 were applied. The experiment was conducted by split-plot method. Ebermeier’s lysimeters (open type: 80 × 80 × 10 cm) were conducted for collecting leachate for measuring nitrogen leaching. The soybean grain yield showed statistical very significant differences in growing season, irrigation and interaction of growing season and irrigation. Mean leaching NO 3 -N varied from 0.32 kg N ha −1 to 7.88 kg N ha −1 in year 2001, while were greater in year 2005 and varied form 2.41 kg N ha −1 to 23.71 kg N ha −1 .
Abstract
The activity concentration of beryllium-7 (7Be), a naturally occurring cosmogenic radionuclide produced in the upper atmosphere, was measured in plants on the Loess plateau of China during the growing season of 2005. The 7Be mass activity concentration on July 27 ranged from 34.8 to 147.1 Bq kg−1 in herbaceous plants, from 47.6 to 116.1 Bq kg−1 in subshrubs, and from 15.7 to 56.8 Bq kg−1 in crop plants. The 7Be mass and areal activity concentrations of a mixture of herbaceous plants increased from 66.8 to 288.7 Bq kg−1 and from 0.7 to 46.5 Bq m−2, respectively, during the growing season. On an areal basis, the fraction of 7Be in plants in the soil–plant system increased from 0.4 to 8.4% during the growing season. Positive linear correlations were found between the increases of 7Be mass and areal activity concentrations in the inter-sampling intervals and the amount of precipitation.
The objective of the investigation was testing of sunflower hybrids in different environmental conditions. Trials were set up at three locations (Osijek —Eastern Slavonia county, Karanac — Baranja county, and Feričanci — Western Slavonia county) during the 2002 and 2003 growing season. Fourteen sunflower hybrids were tested. Stability and adaptability analysis was performed using two parameters — regression coefficient (b i ) and deviations mean square (s 2 di ). Determined were hybrids characterized by high and stable grain yield and wide general adaptability and hybrids for low and high yielding environments. The investigation showed no significant differences among single cross and three-way cross hybrids regarding grain yield stability.
Field experiments were conducted during the two growing seasons of 1999 and 2000 at the research farm of the Jordan University of Science and Technology (JUST) to study the effect of the time of weed removal on the yield and yield components of faba bean (Vicia faba L.). Removing weeds from 25 to 75 days after crop sowing led to significantly larger yields than on plots which were not weeded. Maximum yield was obtained in both years when weeds were removed thrice at 25, 50 and 75 days after crop sowing.
Nine bitter vetch selection lines were evaluated in three successive years to determine their yield and seed index (100-seed weight) stabilities, based on three parameters: phenotypic index (P), regression coefficient (bi), and least deviation from regression (S2 di). The line Sel. 2517 (L7) was identified as the most stable one for the growing seasons, while Sel. 2509 (L2) and Sel. 2511 (L4) were found to be stable for seed yield under favourable climatic conditions. For seed index Sel. 2515 (L6) was identified as the most stable line. Selection line 2513 (L5), which originated from Cyprus, had the highest degree of responsiveness to changing environments.
The effect of four rhizobacterial strains on the severity of spot blotch disease caused by cochliobolus sativus was evaluated for two growing seasons under rainfed conditions. Three barley genotypes were used as host plant. All strains reduced C. sativus severity, with effect more pronounced when Pseudomonas putida BTP1 and Bacillus subtilis Bs2508 were used. The disease reduction was up to 56% in Arabi Abiad / P. putida BTP1. The grain yield was not obviously affected by the presence of the rhizobacteria, except some signifitive increase in season 2. Raising the resistance by soaking seed with rhizobacterial strains might be of ultimate value in agriculture.
The relationship between the soil seed bank at the onset of the growing season and the structure of the ensuing vegetation under grazing was investigated in an eastern Mediterranean grassland. Species responses to two contrasting cattle grazing regimes were studied through plant trait analyses. Traits included plant size, phenology, seed size and germination fraction. Changes in species composition of the soil seed bank and the vegetation were analyzed using a plant functional group approach. The results showed that seed bank and relative cover of tall annual and perennial grasses increased when grazed late in the growing season. The opposite was noted for short annual grasses, annual legumes, annual thistles, annual crucifers and other annual forbs. Grazing treatments little affected plant cover of herbaceous perennials. Tall annual and tall perennial grasses have large seeds and germination rates over 90%. Short annual grasses showed similarly high germination rates but with smaller seeds. Annual legumes were characterized by medium size seeds and lower germination fractions (<50%). Tall annual grasses showed high competition capabilities at late grazed paddocks due to a combination of regeneration traits that included: high germination fraction, larger seed and seedling size, and inflorescence with morphological defenses. It is proposed that in addition to plant size and palatability, regeneration traits such as seed dormancy, seed and seedling size play an important role in determining the vegetation structure under different grazing regimes, thus contributing to the high plant species diversity characteristic to Mediterranean grasslands.
Wheat is the second most important field crop on arable lands in Hungary and Croatia. Yield variations between years are high in both countries. In the short term these variations are mainly the result of the weather parameters specific to individual growing seasons. The aim of this study was to compare variations in winter wheat yields over years in four counties in Hungary and five in Croatia, with the emphasis on the impact of rainfall and mean air temperature regimes. The results showed that rainfall in spring was most decisive for winter wheat yields. The highest winter wheat yields were obtained when the rainfall in the winter half-year ranged from 230–260 mm and the spring rainfall from 180–230 mm. The precipitation in the growing season is much higher in eastern Croatia than in eastern Hungary, so water shortage is a more pronounced environmental problem for wheat in Hungary. This is probably why wheat yields were lower in eastern Hungary than in eastern Croatia in the period tested. Pearson correlation analysis on the yields and meteorological data between 1990 and 2009 revealed a positive correlation between spring rainfall and the yield, and a negative correlation between spring temperature and the yield. The results proved that yields were determined not only by weather conditions, but by many other factors (crop rotation, tillage, fertilization, variety, crop protection, etc.).
Quality of wheat grain is a complex trait that depends mostly on the quantity and quality of protein and unified interactions between high molecular glutenin, gliadin, low molecular glutenins and abiotic stresses. The objective of this study was to evaluate the effects of genotype, environment and genotype × environment interaction on quality and some agronomic traits in wheat. Twenty divergent genotypes of winter wheat, per five from Serbia, Russia, France and Hungary were analysed in this paper. Variability was observed for quality (grain protein content and sedimentation) and agronomic traits (thousand-grain weight and test weight) in three growing seasons (2007/08, 2008/09 and 2009/10). Genotypes were statistically analysed [basic statistical parameters, AMMI biplot for the content of protein, correlation and Principal Component Analysis (PCA)] in order to assess the impact of different growing seasons on selected cultivars. AMMI analysis determined that 2008/09 was very significant for most of the genotypes. The Hungarian cultivar GK-Zugoly had the highest grain protein content (14.4%). Correlation analysis showed different relationships between the traits. PCA indicated that the total variation reflected the first two components represented with 80%, but the first principal component was more important. Results of this paper indicate that the varieties MV-Csardas and Pamyati Kalinenko can be used as a good source of genetic material for future breeding program for agro-ecological conditions of Vojvodina.
