The production of volatiles on steamed rice by Australian isolates of Fusarium oxysporum f. sp. cubense correlated well with race and vegetative compatibility group (VCG). All race 4 isolates (VCGs 0120, 0129) produced distinctive volatile odours which gave characteristic gas chromatograms where the num- ber of peaks equated to VCG. Race 1 (VCGs 0124, 0125) and race 2 (VCG 0128) isolates, as well as non-pathogenic isolates of F. oxysporum from the banana rhizosphere, did not produce detectable volatiles and gave chromatograms without significant peaks.

The accurate calculation of iron loss from finite element analysis in electrical machines is essential if optimal machines are to be designed. This paper conducts a holistic review of the extensive literature field before examining, in detail, several methods in order to recommend an optimum engineering solution. Both frequency domain and time domain methods are discussed including the use of different orthogonal components as well as the relative merits of using all, or some, of the Eddy Current, Anomalous and Hysteresis loss components. A theoretical cubic meter of iron is simulated to quickly demonstrate the inaccuracies of Cartesian coordinate methods before calculation on several manufactured machines are undertaken showing the superior accuracies of major/minor loop calculation. Calculation undertaken using the radial tangential orthogonal plane is shown to have less than 1% average difference to the major/minor loop yet is over 6 times quicker. The peak percentage error in an individual element is shown to be less than 5%. Discussions are also made regarding the method of curve fitting to gain loss constants and any possible sources of inaccuracy particularly during manufacture.

This paper examines efficient methods for the calculation of open circuit voltage distortion in salient pole synchronous generators with damper windings. It then proceeds to examine the role of damper bars in the level of distortion. The simplified finite element method employed is inclusive of eddy current effects, dynamic field current and full interaction of all MMF sources. It allows accurate total harmonic distortion values to be calculated approximately 25 to 30 times quicker than a fully rotating finite element simulation. Tests have been conducted on eight built machines and results compared to both analytical and alternative finite element methods. The proposed mehtod has an average reduction in error of 55%, compared to an existing analytical method. The presence of damper bars and their position within the pole face is examined, and shown to have a large influence over the level of total harmonic distortion produced.

Effectiveness and length of weed control with atrazine and chlorsulfuron can be variable in the field. While some of this may be due to climatic variations, differences in soil properties may also be important. We tested this by recording changes in control of mintweed (Salvia reflexa Hornem.) and turnip weed (Rapistrum rugosum L.) with time in different soils, and comparing these results with the measured changes in plant-available herbicide in the soils. Length of weed control with the same herbicide rate varied from 0 to >15 weeks. Mintweed and turnip weed were controlled (85-100%) only when the soils had ¸ 0·1µ#9839;g available atrazine/g and 0·8 ng available chlorsulfuron/g, respectively. This agreed with the sensitivity data for these weeds when grown in a soil-free system. The herbicides were initially more available in grey clays than in black earths, and soil pH accounted for most of the variations in the persistence of the available residues. Thus, the efficacy of these herbicides in different soils could be estimated if the available residues in the root-zone could be predicted and the sensitivity of different weeds was known.