108 research outputs found
Phosphine fumigation of cool grain
The biosecurity problem addressed was the need to understand and evaluate phosphine fumigation of cool grain (i.e. 20°C or less) as a means of controlling resistant biotypes of insect pests of stored grain which are major EPPs threatening the grain industry. The benefits of cooling and phosphine fumigation are that cooling preserves grain quality and reduces insect population growth, and phosphine kills insects and has a residue free status in all major markets.
The research objectives were to:
- conduct laboratory experiments on phosphine efficacy against resistant insects in cool grain, and determine times to population extinction.
- conduct laboratory experiments on phosphine sorption in cool grain and quantify.
- complete fumigation trials in three states (Queensland, WA and NSW) on cool grain stored insealed farm silos.
- make recommendations for industry on effective phosphine fumigation of cool grain.
Phosphine is used by growers and other stakeholders in the grain industry to meet domesticand international demands for insect-free grain. The project aim was to generate new information on the performance of phosphine fumigation of cool grain relevant to resistant biotypes. Effective control of resistant biotypes using phosphine to fumigate cool grain will benefit growers and other sectors of the grain industry, needing to fumigate grain in the cooler months of the year, or grain that has been cooled using aeration
How to make a milk market: A case study from the Ethiopian highlands
Some smallholders are able to generate reliable and substantial income flows through small-scale dairy production for the local market; for others, a set of unique transactions costs hinders participation. Co-operative selling institutions are potential catalysts for mitigating these costs, stimulating entry into the market, and precipitating growth in rural communities. Trends in co-operative organisation in East African dairy are evaluated. Empirical work focuses on alternative techniques for effecting participation among a representative sample of peri-urban milk producers in the Ethiopian highlands. The techniques considered are a modern production practice (crossbred cow use), a traditional production practice (indigenous cow use), three intellectual-capital-forming variables (experience, education and extension) and the provision of infrastructure (as measured by time to transport milk to market). A Tobit analysis of marketable surplus generates precise estimates of non-participants distances to market and their reservation levels of the covariates measures of the inputs necessary to sustain and enhance the market. Policy implications focus on the availability of crossbred stock and the level of market infrastructure, both of which have marked effects on participation, and, inevitably, the social returns to agro-industrialisation
INTERACTIVE EFFECT OF COWPEA VARIETY, DOSE AND EXPOSURE TIME ON BRUCHID TOLERANCE TO BOTANICAL PESTICIDES
Callosobruchus maculatus has for years remained a serious menace in
cowpea in Sub-Sahara Africa. The objective of this study was to
investigate the effect of genotypic cowpea ( Vigna unguiculata (L.)
Walp) varieties, time and dose on C. maculatus exposed to powders of
Piper guineense and Eugenia aromatica . Irrespective of duration and
botanicals, bruchid reared on KDV showed the highest tolerance to both
plant materials; while their counterparts from IAR48V were the most
susceptible. Median lethal time (LT50) also varied according to the
plant materials; with the highest in KDV reared bruchid [P. guineense:
KDV (18.31), IAR48V (9.27), IFBV (13.17); E. aromatica: KDV (76.01),
IAR48V (5.59), IFBV (6.49)]. There was a significant impact of cowpea
variety (V), exposure time (T) and dose (D) on the tolerance of C.
maculatus to both plant materials. The effect of all two-way (VxT, VxD,
DxT) and three way interactions (V
7T
7D) on the tolerance of
C. maculatus to both plant materials was also significant. Varietal
effect was more pronounced in bruchids exposed to E. aromatica; while
exposure time was more pronounced in bruchids exposed to P. guineense.Callosobruchus maculatus a \ue9t\ue9 pendant plusieurs
ann\ue9es une menace pour la culture du ni\ue9b\ue9 en Afrique au
Sud du Sahara. L\u2019objectif de cette \ue9tude est
d\u2019\ue9valuer l\u2019effet des g\ue9notypes de
ni\ue9b\ue9 ( Vigna unguiculata (L.) Walp), le temps
d\u2019exposition et la dose de poudre de Piper guineense and
Eugenia aromatica administr\ue9e sur C. maculatus.
Ind\ue9pendamment au temps d\u2019exposition, les bruches
\ue9lev\ue9es sur KDV se sont montr\ue9es les plus
tol\ue9rantes aux poudres des deux plantes; tandis que leur
homologues \ue9lev\ue9es sur IAR48V \ue9taient les plus
susceptibles. Le temps de demi-vie (LT50) aussi varie selon la plante
dont la poudre est administr\ue9e; avec le temps de demi-vie le plus
\ue9lev\ue9 observ\ue9 chez les bruches d\ue9velopp\ue9es sur
KDV [P. guineense: KDV (18.31), IAR48V (9.27), IFBV (13.17); E.
aromatica: KDV (76.01), IAR48V (5.59), IFBV (6.49)]. L\u2019\ue9tude
a r\ue9v\ue9l\ue9 une tr\ue8s grande influence sur les
vari\ue9t\ue9s de ni\ue9b\ue9 (V), le temps d\u2019exposition
(T) et la dose (D) sur la tol\ue9rance de C. maculatus aux deux
esp\ue8ces v\ue9g\ue9tales. L\u2019effet de toutes les
interactions de deux (VxT, VxD, DxT) ou des trois facteurs
(V
7T
7D) sur la tol\ue9rance de C. maculatus aux deux
esp\ue8ces v\ue9g\ue9tales \ue9tait aussi significatif.
L\u2019effet de g\ue9notype \ue9tait plus prononc\ue9 sur les
bruches expos\ue9es \ue0 E. aromatica; tandis que l\u2019effet de
temps d\u2019exposition \ue9tait plus prononc\ue9 sur les bruches
soumises \ue0 P. guineense
An artificial diet for butterflies, including Bicyclus species, and its effect on development period, weight and wing pattern
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Chemical defence in ladybird beetles (Coccinellidae). I. Distribution of coccinelline and individual variation in defence in 7-spot ladybirds (Coccinella septempunctata)
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Ab initio Quantum and ab initio Molecular Dynamics of the Dissociative Adsorption of Hydrogen on Pd(100)
The dissociative adsorption of hydrogen on Pd(100) has been studied by ab
initio quantum dynamics and ab initio molecular dynamics calculations. Treating
all hydrogen degrees of freedom as dynamical coordinates implies a high
dimensionality and requires statistical averages over thousands of
trajectories. An efficient and accurate treatment of such extensive statistics
is achieved in two steps: In a first step we evaluate the ab initio potential
energy surface (PES) and determine an analytical representation. Then, in an
independent second step dynamical calculations are performed on the analytical
representation of the PES. Thus the dissociation dynamics is investigated
without any crucial assumption except for the Born-Oppenheimer approximation
which is anyhow employed when density-functional theory calculations are
performed. The ab initio molecular dynamics is compared to detailed quantum
dynamical calculations on exactly the same ab initio PES. The occurence of
quantum oscillations in the sticking probability as a function of kinetic
energy is addressed. They turn out to be very sensitive to the symmetry of the
initial conditions. At low kinetic energies sticking is dominated by the
steering effect which is illustrated using classical trajectories. The steering
effects depends on the kinetic energy, but not on the mass of the molecules.
Zero-point effects lead to strong differences between quantum and classical
calculations of the sticking probability. The dependence of the sticking
probability on the angle of incidence is analysed; it is found to be in good
agreement with experimental data. The results show that the determination of
the potential energy surface combined with high-dimensional dynamical
calculations, in which all relevant degrees of freedon are taken into account,
leads to a detailed understanding of the dissociation dynamics of hydrogen at a
transition metal surface.Comment: 15 pages, 9 figures, subm. to Phys. Rev.
Fungicide resistance management in Australian grain crops
Fungicide resistance is a serious and increasing problem in cropping systems worldwide. Fungicides are an important component of integrated disease management strategies for the protection of crops from the impacts of fungal diseases. However, as their use has increased, the effectiveness of some fungicides has been reduced by the development of fungicide resistant pathogen populations. Without intervention, more fungicides are likely to become ineffective
Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4
Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events
We present a measurement of the W+W- production cross section using 184/pb of
ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the
Collider Detector at Fermilab. Using the dilepton decay channel W+W- ->
l+l-vvbar, where the charged leptons can be either electrons or muons, we find
17 candidate events compared to an expected background of 5.0+2.2-0.8 events.
The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-)
= 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the
Standard Model expectation.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review
Letter
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