A method of analysis for the determination of binapacryl,bupirimate and diflubenzuron on apple foliage and fruit,and its application to persistence studies

A rapid, sensitive and specific high-pressure liquid chromatographic method was developed to analyse residues of binapacryl, bupirimate and diflubenzuron on mature foliage and fruit at intervals after application of the compounds to Worcester and Cox apple trees. The three compounds were applied as commercial formulations in trials to compare integrated pest management with routine farm spray-programmes. The identities of the residues were confirmed by a combination of thin-layer chromatography, ultraviolet spectrometry and gas chromatography/mass spectrometry. Only diflubenzuron persisted on foliage until leaf-fall. None of the applied compounds was detectable on harvested fruit, the minimum quantifiable residue levels being 1, 5 and 2.5 μg kg^?1 fresh weight for binapacryl, bupirimate and diflubenzuron, respectively.     

Training in animal handling for veterinary students at Charles Sturt University, Australia

Charles Sturt University in New South Wales, Australia, is responding to a national need for veterinarians with the skills and attributes to fulfill roles in rural practice and the large-animal industries. Rural practitioners must competently and confidently handle a range of large animals if they are to build a relationship of mutual trust with clients and deliver effective animal-health services. Training in animal handling begins in the first year of the course with highly structured small-group practical classes involving cattle, horses, sheep, dogs, cats, pigs, poultry, and laboratory animals (rats and mice). Other experiences with animals in the first three years build on basic animal-handling skills while performing other veterinary activities. Students who provide documented evidence of prior animal-handling experiences are admitted, and learning and teaching strategies aim to enhance skills and knowledge. Rigorous examinations use a competency-based approach prior to extramural placements on farms and in veterinary practices. A continuing process of evaluation, review, and refinement will ensure continual improvement and graduate veterinarians with strong skills in animal handling.     

Identifying declines in waterbirds: The effects of missing data, population variability and count period on the interpretation of long-term survey data

To manage and conserve wildlife populations effectively it is necessary to use methods that identify the often non-linear trends in populations, have an inbuilt assessment of trend quality and can analyse count data from a range of spatial scales. We present a method of trend analysis using generalised additive models. These produce smoothed indices of abundance that can be used to assess population change from one or more sites or time periods, with any number of estimates of abundance per index period. We apply this method to count data collected under the Wetland Bird Survey, a national scheme that monitors waterbirds in the United Kingdom. To highlight declining populations, ‘alerts’ were raised if the population decline was equal to or greater than 50%. Significance was determined using bootstrapped confidence intervals for analyses that included many sites, or a novel Monte-Carlo method for single site analyses. The impact of missing data, species count variability and the number of months used to calculate the population change was greater at individual sites than for national datasets, which were relatively insensitive to changes in the above parameters. For single sites it is essential that three or more counts be made per index period if reliable estimates of population change are required. We propose that the method presented could be applied to a wide range of national or other monitoring schemes for a variety of taxa.     

Effect of soil pH on mineral element concentrations of two erythroxylum species

Erythroxylum coca var. coca Lam. (E. coca) and Erythroxylum novogranatense var. novogranatense (Morris) Hieron (E. n. novogranatense) are two of four Erythroxylum species grown in the tropics of South America for cultural medicines and the alkaloid benzoylmethylecgonine. In a published study of biomass production over a soil pH range of 3.5 to 7.0, E. coca grew best at a pH equal to and below 5.5, and E. n. novogranatense grew best within the pH range of 4.7 to 6.0. Erythroxylum coca was tentatively classified as more tolerant to metal toxicities [aluminum (Al) and manganese (Mn)] than E. n. novogranatense, however, concentration patterns of mineral elements for E. coca and E. n. novogranatense tissue have not been reported, nor have the mechanisms of differential acid‐soil‐tolerance been elucidated. In the current study, the effects of soil pH on concentrations of Al, calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), Mn, and zinc (Zn) in leaves, stems, and roots were investigated. At pH 3.5, roots of both species accumulated high concentrations of Al that decreased as soil pH increased, however, there was no pH × species interaction. The highest concentration of Ca was found in the leaves of both species, however, E. coca accumulated more Ca as soil pH increased than did E. n. novogranatense. Manganese and Zn levels were highest in roots of both species (E. coca and E. n. novogranatense); levels in all tissues decreased with increasing pH. Manganese concentration was highest in roots of E. coca and Zn concentration was highest in tissues of E. n. novogranatense. Copper, Fe, K, and Mg levels were erratic with increasing pH, indicating that sufficient amounts of these nutrients are acquired at low pH levels. Root concentrations of Fe and K in E. coca increased markedly between pH 3.5 and 4.7. At pH 3.5, E. coca demonstrated no symptoms of mineral deficiency and/or toxicity, however, chlorosis, leaf distortion and root atrophy were prevalent at pH 6.5 and 7.0. By contrast, E. n. novogranatense demonstrated diminished growth and root atrophy at soil pH 3.5, whereas at pH 6.5 and 7.0, although biomass production was reduced, no symptoms of mineral deficiency and/or toxicity were present. The species obviously behave differentially at pH extremes and E. coca appears to be most tolerant of extremely acid soils; the two species may also differ in mineral sensitivities between the species at higher pH levels. Erythroxylum coca may compete more effectively with Al for Ca binding sites within the root, and may have greater internal tolerance of Mn, compared with E. n. novogranatense.     

Bulb Formation in Onions as Affected by Photoperiod and Spectral Quality of Light

In glasshouse experiments bulb formation occurred in 5 north-temperate onion cultivars in photoperiods of 14–15 h and longer. Some response was obtained by giving 14 long days, but a greater response was obtained when the plants were kept in continuous long days. Three cultivars in the Rijnsburger group all differed from each other in the extent of their bulb development in all of several photoperiodic regimes tried, but there was no cultivar × photoperiod interaction. Thus it is possible that cultivars could usefully be compared in the glasshouse for earliness by providing any one of a wide range of photoperiodic treatments.

When grown in controlled environments with artificial light, little or no bulb formation occurred in cv. Rijnsburger with warm-white fluorescent lamps, but with de-luxe warm-white lamps it occurred when the photoperiods were 17 or more hours long. These lamps appeared to be elfective because they emitted a greater proportion of far-red light than the warm-white lamps, although not as much as sunlight. Because it is possible that the sensitivity of cultivars to the spectral composition of light may vary, it is concluded that attention should be given to this in comparative studies of the photoperiodic requirements of different cultivars.