Soil organic matter and sorption capacity under different soil management practices in a productive vineyard

The effect of soil organic matter (SOM) on sorptive parameters under different soil management practices in Rendzic Leptosol was studied. In 2006, an experiment of different management practices in a productive vineyard was established in the locality of Nitra-Dra?ovce (Slovakia). The following treatments were established: (1) control (grass without fertilization), (2) T (tillage), (3) T + FYM (tillage + farmyard manure), (4) G + NPK3 (grass + 3rd intensity of fertilization for vineyards), (5) G + NPK1 (grass + 1st intensity of fertilization for vineyards). Soil samples were collected every month during the year 2010. Obtained results showed increased hydrolytic acidity (by 23%), sum of basic cations (by 37%) and decreased total cation exchange capacity (CEC) (by 36%) with higher doses of fertilization in comparison to control. Application of farmyard manure had a positive effect on the increase in the SOM cation sorption capacity. Positive correlations between pH and sum of basic cations (SBC) (r = 0.493, p ≤ 0.001), CEC (r = 0.498, p ≤ 0.001) and cation sorption capacity of SOM (r = 0.391, p ≤ 0.01) were observed. Higher values of labile carbon:potentially mineralizable nitrogen (C_L:N_pot) ratio corresponded with lesser CEC, SBC and base saturation values in the soil. With increased humus quality (higher values of humic acid:fulvic acid (C_HA:C_FA) ratio), cation sorption capacity of SOM significantly increased (r = 0.329, p ≤ 0.01). The results of this study proved that the application of farmyard manure had a positive effect on the increase of SOM sorption capacity, but higher doses of mineral fertilizers added to soil had a negative effect.     

Influence of variety and growing location on the development of off-flavor in precooked vacuum-packed potatoes.

Development of potato off-flavor (POF) was examined in precooked vacuum-packed potatoes by GC and sensory analyses. The experiments comprised four varieties grown at two locations. Aroma compounds shown to be potential contributors to POF were determined quantitatively, and their relative importance was interpreted by aroma values based on odor detection threshold values determined in water. There were statistically significant differences in the content of POF compounds between the growing locations and among some of the varieties. The results from the sensory analyses concurred roughly with the GC analyses. (E,E)-2,4-Nonadienal and (E, E)-2,4-decadienal were shown to be the most potent of the POF compounds examined, in addition with hexanal, (E)-2-octenal, and (E)-2-nonenal. Lowering the development of POF in precooked vacuum-packed potatoes should be possible by optimizing the environmental conditions and breeding for suitable varieties.     

Comparison of isolation methods for the determination of important aroma compounds in black currant (Ribes nigrum L.) juice, using nasal impact frequency profiling

The influence of isolation method on the determination of important aroma compounds in black currant juice was investigated by surface of nasal impact frequency (SNIF) gas chromatography-olfactometry (GC-O). The applied methods were solvent extraction, static headspace, and purge and trap using 15 and 60 min of purge time. By the four methods, a total of 59 odors were observed, and, of these, 44 corresponded to compounds that could be identified. For the headspace methods increasing purge volumes resulted in recoveries of additional, less volatile compounds. The main compound groups recovered by the headspace methods were esters and terpenes, whereas compounds recovered by solvent extraction were not as dominated by fruity odors. For most compounds there was agreement between the size of the SNIF value obtained by GC-O and the amount of the measurable compound found by gas chromatography-mass spectrometry.     

Volatile monoterpenes in black currant (Ribes nigrum L.) juice: effects of heating and enzymatic treatment by beta-glucosidase

Changes of terpenes in black currant juice induced by the action of heat were investigated in the present study. Limonene, alpha-terpinene, linalool, alpha-terpineol, 4-terpineol, and menthol added to either black currant juice or a model system were thermally treated at 90 degrees C for 30 min. Similar heat-induced decreases in the concentration of the terpenes were observed in the two systems. The concentration of a range of terpene hydrocarbons and oxygenated terpenes increased, alpha-terpineol being a main conversion product of most of the examined compounds. In the main, the measured loss of compounds exceeded the detected concentrations of products formed. In addition, determination of glycosidically bound terpenes in the juice was carried out by two methods of enzymatic hydrolysis, namely, addition of beta-glucosidase to an Amberlite XAD-2 isolate or directly to black currant juice. The two methods gave the same patterns of seven released volatile aglyconic terpenes. However, none of the released terpenes are important for the odor of black currant juice.     

Interaction of minerals,organic matter,and microorganisms during biogeochemical interface formation as shown by a series of artificial soil experiments

Our understanding of the interactions between minerals, organic matter, and microorganisms at so-called biogeochemical interfaces in soil is still hampered by the inherent complexity of these systems. Artificial soil maturation experiments can help to bridge a gap in complexity between simple abiotic sorption experiments and larger-scale field experiments. By controlling other soil-forming factors, the effect of a particular variable can be identified in a simplified system. Here, we review the findings of a series of artificial soil incubation experiments with the aim of revealing general trends and conclusions. The artificial soils were designed to determine the effect of mineral composition and charcoal presence on the development of abiotic and biotic soil properties during maturation. In particular, the development of soil aggregates, organic matter (OM) composition and turnover, sorption properties, and the establishment of microbial community composition and function were considered. The main objectives of the research were to determine (1) how surface properties and sorption of chemicals modify biogeochemical interfaces; (2) how much time is required to form aggregates from mixtures of pure minerals, OM, and a microbial inoculum; and (3) how the presence of different mineral and charcoal surfaces affects aggregation, OM turnover, and the development of microbial community composition.     

A versatile flow cytometry-based immunofluorescence inhibition assay for the detection of bovine viral diarrhea virus-specific antibodies

A fast, sensitive and reliable flow cytometry-based (FACS = fluorescence activated cell sorting) immunofluorescence inhibition assay (FACS-IFI) for the detection of virus-specific antibodies in sera is described. The method was evaluated using sera from cattle experimentally infected with bovine viral diarrhea virus (BVDV). Virus-infected cells, which were fixed and permeabilized, were incubated with diluted sera from immunized or control animals. Monoclonal antibodies (mabs) against different viral proteins were added, and detected with ALEXA488-conjugated goat-antimouse antibodies. The fluorescence signals were detected by flow cytometry and determined as mean channel values. Results were expressed as percent fluorescence inhibition compared to standardized negative sera. The FACS-IFI test with sera from experimentally infected animals was highly sensitive and specific. Comparison of the FACS-IFI results with a commercially available blocking ELISA, an indirect ELISA and the standard serum neutralization test showed a strong correlation. Furthermore, the detection of protein-specific antibodies was possible using the FACS-IFI test.     

The production and growth of young apple compact mutants induced by ionizing radiation

The main purpose of this work was to produce compact mutants of apple, i.e. mutants which had shorter internodes and often shorter shoots than is normal for the variety.Scions of the apple varieties Cortland, Ingrid Marie, Gråsten, Close, Golden Delicious and Ildrød Pigeon were treated with gamma radiation (3000–7000rad). Following two propagations compact mutants were selected on the basis of internode length. All mutants, whose internode length was significantly shorter than that of the normal variety, are included in Tables 3, 4, 5 and 6. Most of these mutants had shorter shoots and thicker shoot diameters than the normal variety.The correlation between shoot length and internode length has made necessary the introduction of the term degree of compactness to characterize the mutants. If the relationship between internode length and shoot length of a mutant is similar to that of the normal variety then it has a low degree of compactness. If, however, the mutant's internode length is considerable less than is normal for the variety (still in relation to shoot length), then the degree of compactness is great. The selected mutants are grouped according to degree of compactness in Tables 3, 4, 5 and 6, beginning with mutants which are less compact.In all 8 Cortland, 11 Ingrid Marie, 9 Gråsten, 3 Close, 1 Golden Delicious and 1 Ildrød Pigeon compact mutants were found.     

A new inactivated BVDV genotype I and II vaccine. An immunisation and challenge study with BVDV genotype I

An inactivated vaccine containing BVDV I and II strains (PT810; BVDV I, and 890; BVDV II) and using different adjuvants and antigen dosages was tested in a cattle challenge model. Groups of six healthy, seronegative cattle were vaccinated twice with a low dose (10(6.6) TCID(50) PT810 and 10(7.2) TCID(50) 890) vaccine with the adjuvant Bay R1005 or a high dose (10(7.8) TCID(50) PT810 and 10(8. 2) TCID(50) 890) vaccine with two different adjuvants (Bay R1005 or Polygen). Thirty-eight days after the second vaccination, immunised animals (n=18) and non-vaccinated control animals (n=3) were challenged intranasally with 10(6) TCID(50) BVDV strain PT810. For a period of 16 days, virus was isolated from blood leukocytes and nasal swabs, and neutralising antibody titres were determined.The induction of antibodies following immunisation was strongly dependent on the antigen dosage in the vaccine. The high dose formulation induced high serum neutralising antibody titres against both genotypes of up to 32000 after the second immunisation. Animals with neutralising antibody titres >512 (n=14) did not show any marked leukopenia after challenge and only very little or no virus could be isolated from blood leukocytes and/or nasal swabs when compared to control cattle. Furthermore, some of these animals did not show any boost of neutralising or even NS3-specific antibodies, which renders viral replication unlikely and thus would prevent infection of the fetus. Both adjuvants (Bay R1005 or Polygen) were similarly efficient and induced nearly identical antibody responses. In contrast, four of the six low dosage vaccinates had a marked leukopenia and viraemia as well as detectable nasal virus shedding for several days.We conclude that the selected strains and the system of vaccine preparation with high BVDV antigen dosages and highly efficient new adjuvants provide an effective means of protection against BVDV I infections. Investigations to demonstrate the protection against BVDV II infections, the duration of immunity and the ability of fetal protection by using the high dose vaccine in a fetal challenge model will follow.