Anaerobic Soil Disinfestation and Brassica Seed Meal Amendment Alter Soil Microbiology and System Resistance

ABSTRACT

Brassica seed meal amendments and anaerobic soil disinfestation (ASD) control a spectrum of soil-borne plant pathogens via a diversity of mechanisms. Transformations in microbial community structure and function in certain instances were determinants of disease control and enhanced plant performance. For instance, in strawberry field soils, increased strawberry yields in response to ASD were attained in a carbon-source input-dependent manner. ASD conducted with rice bran as the carbon input, but not molasses, resulted in significantly greater yields. Effective ASD treatments, but not ineffective treatments, resulted in increased abundance of bacteria in phylum Bacteroidetes in treated soils, specific genera of which are known to provide biological disease control. Brassica seed meal amendment resulted in development of a soil system suppressive towards disease incited by the root pathogen Macrophomina phaseolina. Brassica seed meal treated orchard soil systems exhibit resistance to re-infestation by soil-borne pathogens, including the plant parasitic nematode Pratylenchus penetrans. System resistance is associated with significant and prolonged changes in rhizosphere microbiology and specifically amplification of specific organisms with potential to parasitize P. penetrans.     

Lead exposure induces pycnosis and enucleation of peripheral erythrocytes in the domestic fowl

Lead (Pb) shot were administered orally to young chickens to determine the effects on red blood cells (RBCs). The concentrations of Pb in the blood of young chickens rose rapidly after Pb administration and were maintained at high levels for several days. The number of RBCs with pycnotic nuclei, reticulocytes and enucleated RBCs increased concurrently. Pycnotic nuclei were surrounded by enlarged nucleolemmal cisternae, which sometimes opened to the extracellular space. Gel electrophoresis showed that the presence of pycnotic nuclei was not associated with DNA fragmentation typical of apoptosis. It was concluded that exposure to lead shot changes nuclear morphology in the peripheral blood of domestic fowl.     

New Modified Dipping Method Using 4-hexylresorcinol for Preventing Blackspot Formation in Prawns

Industry acceptance of alternative sulphite treatments for preventing blackspot in prawns is limited. This study demonstrated that dipping prawns (Penaeus monodon and Fenneropenaeus merguiensis) in a less concentrated solution for longer times provides better control of blackspot formation than the recommended 2 minute dip in 50 mg/L 4-hexylresorcinol. Protection improved as modified dipping times and solution concentrations increased. Blackspot protection provided by most of the modified dip methods was more effective than a 1 minute dip in 1% sodium metabisulphite. The recommended 2 minute dip method should be limited to 125 kg when used on consecutive 25-kg batches of prawns. Yields increased by less than 10% even after 72-hour exposure in the modified dip. The new dipping method meets most international residue standards when applying the modified treatments evaluated.     

The abundance of common bottlenose dolphins (Tursiops truncatus) in the former special marine reserve of the Cres‐Lošinj Archipelago,Croatia

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