Tuber Position in the Ridge in Relation to the Planting Depth with the Technology of Simultaneous Planting and Final Ridge Formation

Simultaneous planting and final ridge formation using a deeper planting depth is necessary in order to achieve good soil cover of tubers and fewer green tubers. Three planting depths were used: planting depth 1 (the shallowest), planting depth 2 (the medium), and planting depth 3 (the deepest). Planting depth 3 led to the largest minimum distance of tubers from the ridge side, and the smallest percentage of tubers in the upper layer of the ridge (0 to 5 cm). However, the highest yield and percentage of green tubers and the smallest marketable yield occurred at the shallowest planting depth (1). The tuber cluster covers 80 to 90% of the area of the ellipse. Empty spaces surrounding the tuber cluster in the ridge also affect the percentage of green tubers in the ridge, which predominantly occur at planting depth 3 and are the rarest at planting depth 1.     

Insect pest management agents: hormonogen esters (juvenogens)

The chemical part of this investigation focused on designing structures and synthesizing a series of six new esters (juvenogens), derived from biologically active insect juvenile hormone bioanalogues (juvenoids, JHAs) and unsaturated short-chain linear and branched fatty acids for possible application as biochemically targeted insect hormonogen agents. The structures of the new compounds were assigned on the basis of a detailed NMR analysis of their (1)H and (13)C NMR spectra. The biological part of this investigation focused on introductory biological screening tests with these compounds against the red firebug (Pyrrhocoris apterus), termites (Reticulitermes santonensis and Prorhinotermes simplex), and the blowfly (Neobellieria bullata). The biological activity of the juvenogens was studied in relation to the fatty acid functionality in the structures. Notable biological activity in topical tests and medium activity in peroral tests was found for the juvenogens 3 and 7 with P. apterus. The compounds 6 and 8 showed the lowest activity in both topical and oral assays with P. apterus. Considerable effect of all tested juvenogens was observed in P. simplex; however, the juvenogens 5 and 6 (derivatives of the only branched short-chain fatty acid) showed no activity against R. santonensis. The effect of the compounds 3-8 on larval hatching of N. bullata was only moderate (larval hatching 80-90%); however, the proliferation effect caused by 5, 6, and 8 is more pronounced than the effect caused by 3, 4, and 7.     

Influence of clay minerals on the formation of humic substances by Epicoccum nigrum and Stachybotrys chartarum

The influence of montmorillonite, kaolinite and finely ground quartz on the formation of humic acid-type polymers by Epicoccum nigrum and Stachybotrys chartarum was studied. The fungi were grown in shake and in deep (4 cm) or shallow (1.5 cm) stationary cultures. In general, clay shortened the time required for the formation of dark colored substances and increased the amounts of humic acid-type polymers in the culture solutions or extracted from the cells with NaOH. In some tests, the time of maximum humic polymer accumulation was much earlier in the presence of clay but total amounts formed in check cultures eventually equalled that of the cultures with clay additions. The ratios of the total humic acid to the total cell substance or to the glucose consumed were also generally increased by montmorillonite. Kaolinite and quartz exerted a similar but less pronounced effect. In deep stationary cultures of S. chartarum, total growth and humic acid formation was sometimes depressed by the higher concentrations of montmorillonite but in shallow cultures biomass and humic acid formation were increased. In cultures with an initial pH of 6.0, humic acid polymers were formed in the cells before they appeared in the solutions. During autolysis, some of the cellular polymers were either released into the medium or became more readily extractable with NaOH. The clays did not appreciably alter the chemical properties of the humic polymers, namely, C and N contents, exchange capacity, COOH groups, total acidity, or phenols released upon sodium amalgam reduction. In the presence of clays, phenols were formed more quickly in the culture solutions, but the kinds and relative amounts did not appear to be altered. Clays did not significantly affect oxygen consumption during autoxidation of phenol mixtures. The observations indicate that, by affecting growth and metabolism, the clays indirectly influence phenolic polymer formation.     

Infrarotspektren der mikrobiellen Biomasse und der Huminsäure im Podsolboden

IR-Spectra of Microbial Biomass and Humic Acid from Podzol IR-examination of soil samples from podzol with or without different pretreatments was carried out in order to check the possibility of humic acid and microbial biomass detection. Pure humic acid and microbial biomass, both isolated or enriched from the soil under controle, showed distinct absorption bands or shoulders at 1730cm^?1, 1620cm^?1 and 1380cm^?1. Only weak absorption bands at the respective wave numbers were detected in the untreated soil sample.     

Wechselbeziehungen zwischen Mikroorganismen und Pflanzen—eine Übersicht

Relationships between microorganisms and plants—a review Relationships between microorganisms and plants are considered to be an important part of microbial ecology. At present, their study is more concerned with the rhizosphere and less with the phyllosphere. Different microecological aspects of these relationships, furthermore the relationships between individual groups of microorganisms and also biochemical effects of microorganisms on plants are thoroughly examined. Nitrogen fixing bacteria, mycorrhizal fungi and phytopathogenic microorganisms are emphasized because of their particular importance for plant growth. Modern working methods (i.e. scanning electron microscopy, radiometry, gas chromatography, etc.) are widely used. For a closer examination of very complex problems, the micro-organisms-plants relationships should be consequently considered to be a part of an open ecological system with mostly continual nutrient cycling.     

Entwicklungen in der Ökologie der Bodenmikroorganismen—eine Übersicht

Developments in the ecology of soil microorganisms - a review In the ecology of soil microorganisms, much interest is focussed at present to the factors of soil microenvironment. The ability of solid particles to adsorb different microorganisms, their nutrients and metabolites is investigated. Furthermore, the macroecological factors, such as geographic locality, climate, soil temperature, moisture etc., which influence the distribution of different microorganisms in soils are considered. Microorganisms and their activity in soils of tropical and arctic regions are also investigated. Concerning the temperate zone, the extensive research of microbial ecology is continued, in order to maintain soil fertility and to solve different environmental problems.     

Modeling acidification and recover in the roofed catchment at Lake Gårdsjön

The dynamic, biogeochemical model SAFE was applied to a roofed subcatchment G1 at Gårdsjön, Sweden. The roof was installed in 1991, and deposition of anthropogenic S and N reduced by ca. 90%. Initiated from pre-industrial steady-state conditions, SAFE predicts present levels of biologically relevant chemical properties (pH, inorganic Al and base cations). SAFE overestimates the short-term effects of the manipulation on runoff pH, while the modeled decline in inorganic Al and and base cations are comparable to observations. Temporal variability and too few years of measured data make model to data comparison difficult. Sulfate desorption, which is not included in SAFE, may introduce a time lag between modeled and measured data. Reductions of S and N inputs by 90% will lead to a recovery in pH, low A1 but extremely low base cations concentrations due to replenishment of exchange sites.     

Adhesion of Salmonella enterica serotype Enteritidis isolates to chicken isthmal glandular secretions

The ability of Salmonella enterica serotype Enteritidis isolates to adhere to immobilized secretions of the isthmus of the laying hen was determined in an ELISA-type assay. One-third of the 56 isolates tested in the logarithmic growth phase, adhered to the isthmal secretions. Using a binding assay of the isolates to thin paraffin sections of the oviduct, we demonstrated that the receptor of the adhesion was localized inside the tubular gland cells of the isthmus. The adhesion to immobilized isthmal secretions as well as to the paraffin sections was blocked by the addition of mannose. A fimD mutant of S. Enteritidis, lacking type 1 fimbriae, did not adhere, confirming that the adhesion was mediated by type 1 fimbriae. Mannosylated glycoproteins were demonstrated in the isthmus glandular cells using confocal laser scanning microscopy by FITC-labelled Lens culinaris lectins. It is hypothesized that the binding of S. Enteritidis to isthmal secretions could play a role in the contamination of eggs through incorporation of the bacteria in the shell membranes.     

Modeling the nucleus and jets of comet 81P/Wild 2 based on the Stardust encounter data

We interpret the nucleus properties and jet activity from the Stardust spacecraft imaging and the onboard dust monitoring system data. Triangulation of 20 jets shows that 2 emanate from the nucleus dark side and 16 emanate from sources that are on slopes where the Sun's elevation is greater than predicted from the fitted triaxial ellipsoid. Seven sources, including five in the Mayo depression, coincide with relatively bright surface spots. Fitting the imaged jets, the spikelike temporal distribution of dust impacts indicates that the spacecraft crossed thin, densely populated sheets of particulate ejecta extending from small sources on the rotating nucleus, consistent with an emission cone model.