SASEV Journal Abstracts

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SASEV Journal Abstracts

The following research results, of which the abstracts are provided here, have been published in the South African Journal of Enology and Viticulture.

Cover Crop Management in a Chardonnay/99 Richter Vineyard in the Coastal Region, South Africa. 3. Effect of Different Cover Crops and Cover Crop Management Practices on Organic Matter and Macro-nutrient Content of a Medium-textured Soil
J.C. Fourie¹, G.A. Agenbag² & P.J.E. Louw¹ ¹ ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa ² Department of Agronomy, Stellenbosch University, Stellenbosch 7600, South Africa
The trial was conducted over a period of 10 years (1993/94 to 2002/03) on a medium-textured soil in a Chardonnay/99 Richter vineyard near Stellenbosch (33°55’S, 18°52’E), which is situated in the Coastal wine grape region of the Western Cape, South Africa. Sixteen treatments, consisting of three cereals and five legumes, managed according to two cover crop management practices, were included. These treatments were compared to a control, in which no cover crop was sown and the weeds were controlled mechanically in the work row and chemically in the vine row from bud break to harvest (approximately the first week of February). A treatment in which no cover crop was sown and full-surface post-emergence chemical weed control was applied from before bud break to harvest (BB) (weedchem) was also included. After five seasons, the soil organic matter (SOM) content in the 0 to 300 mm soil layer increased in all the cover crop management treatments. In weedchem and in the control, SOM remained unchanged and decreased by 16% respectively. The SOM content in the 0 to 150 mm soil layer of the cover crop treatments was, with the exception of Vicia dasycarpa Ten. (grazing vetch), significantly higher than that of the mechanically-cultivated control after a period of 10 years. The SOM content in the 0 to 300 mm soil layer of Secale cereale L. v. Henog and the treatments in which the N-fixing cover crops were sown (with the exception of grazing vetch) was significantly higher than that of weedchem. The total inorganic N (TIN) concentration of the 0 to 150 mm soil layer in the BB treatments of the two Medicago species and Trifolium subterraneum L. v. Woogenellup, as measured for the 1996/97 season during full bloom of the grapevines, was significantly higher than that of the control, weedchem, and the treatments in which full-surface chemical control was applied after bud break (AB). The TIN concentration of the 0 to 600 mm soil layer in the AB treatment of a species, measured after harvest in 2002/03, tended to be higher than that of the BB treatment of that species. The applied treatments had no significant effect on the exchangeable K, Ca and Mg.
South African Journal of Enology and Viticulture Volume 28 No. 1 2007 61 - 68

Fingerprinting and Identification of Bacteria Present in UASB Granules Used to Treat Winery, Brewery, Distillery or Peach-lye Canning Wastewater
M. Keyser, T.J. Britz & R.C. Witthuhn
Department of Food Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
The effective operation of the anaerobic digestion process in an upflow anaerobic sludge blanket (UASB) bioreactor is dependent on the microbial composition of the UASB granules. The granules contain a consortium of bacteria, with a specific metabolic function for each group, contributing to the overall efficiency and stability of the bioreactor. The aim of this study was to fingerprint and identify the bacteria present in four different types of South African UASB granules that are used to treat winery, brewery, distillery and peach-lye canning wastewaters. This was done by combining conventional microbiological platings with PCR-based denaturing gradient gel electrophoresis (DGGE) and DNA sequence analysis. Each granule type showed distinct PCR-based DGGE fingerprints with unique bands, while other bands were found to be present in all the granules, regardless of the wastewater being treated. Sixty-eight different bacteria (40 pure isolates and 28 clones) were partially sequenced and identified from the winery, brewery, distillery and peach-lye canning granules. Thirty-five percent of the identified bacteria represented the unculturable bacteria and 65% represented the culturable bacteria, which included members of the following genera: Bacillus, Pseudomonas, Bacteroides, Enterococcus, Alcaligenes, Clostridium, Shewanella, Microbacterium, Leuconostoc, Sulfurospirillum, Acidaminococcus, Vibrio, Aeromonas, Nitrospira, Synergistes, Rhodococcus, Rhodocyclus and Syntrophobacter. A DGGE marker was successfully constructed, representing members of the bacterial consortium in UASB granules.
South African Journal of Enology and Viticulture Volume 28 No. 1 2007 69 - 79

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