10 articles in this issue
W.J. Conradie
A field trial with two Vitis vinifera L. cultivars, viz. Bukettraube (white) and Heroldrebe (red), grafted onto Ramsey, was carried out over a nine-year period on a sandy, duplex soil. The control (No) received no N, while three other treatments each rece... see more
The effects of timing of nitrogen fertilisation and of different sources (organic vs inorganic) on leaf analysis, juice analysis and wine quality for grapevines on a sandy soil with low organic material were investigated over a period of nine years. Two V... see more
K. MacNamara,C.J. van Wyk,O.P.H. Augustyn,A. Rapp
A vacuum fractional distillation procedure is described for separating both the matrix components and flavour compounds of a whiskey into well-defined groups based on differences in azeotropic boiling points. The distillation was carried out at near ambie... see more
The volatile compounds isolated from whiskey by fractional vacuum distillation were identified by two-dimensional capillary gas chromatography/mass spectrometry. Changing levels with ageing were quantified for the most abundant compounds by direct split i... see more
K. MacNamara,C.J. van Wyk,P. Brunerie,O.P.H. Augustyn,A. Rapp
The low-volatility wood-originating compounds isolated from whiskey by vacuum fractional distillation were analysed by high-resolution gas chromatography and mass spectrometry (GC-MS). Three phenolic esters previously unreported in whiskey were identified... see more
M. Manley,A. van Zyl,E.E.H. Wolf
Fourier transform near-infrared (FT-NIR) spectroscopy can be used as a rapid method to measure the percentage of sugar and to discriminate between different must samples in terms of their free amino nitrogen (FAN) values. It can also be used as a rapid me... see more
M. Garcia,P. Gallego,C. Daverède,H. Ibrahim
In order to study the lack of acidity in wines made out of cv. Negrette, a problem partially due to a high potassium content, this cultivar was grafted onto three different rootstocks, which were then grown in a nutrient solution. Although cation nu... see more
M. Garcia,H. Ibrahim,P. Gallego,P.H. Puig
The cultivar was found to have high potassium content in leaves, musts and wines. To study the contribution of rootstock to this problem, Negrette was grafted onto 101-14 Mgt, 3309 C and SO 4 and grown in the same nutrient solution. The Negrette/330... see more
V.M. Walton,K.L. Pringle
The effects of frequently used grapevine insecticides and fungicides on adults of the predatory beetle Nephus 'boschianus' of vine mealybug, Planococcus ficus (Signoret), were determined under laboratory conditions. When applied as cover sprays the pestic... see more
F. Halleen,G. Holz
Grape powdery mildew, caused by Uncinula necator, is the most widespread and destructive disease of grapevine. The disease can be found in most grape-growing areas of the world, including the tropics. In South Africa, grape powdery mildew was first ... see more