The progression of primary bud necrosis in the grapevine cv. Shiraz (Vitis vinifera L.): A histological analysis

Primary Bud Necrosis (PBN) is a physiological disorder occurring in the compound axillary buds of grapevines. PBN causes the axillary bud to senesce and in some cases secondary buds can also abort. Since PBN is common in the grapevine variety Shiraz the aim of this study was to characterise anatomical changes at different stages of PBN development in this cultivar. Grapevine buds were collected from a vineyard located at Charleston, South Australia, Australia. Buds were dissected, assessed for the presence of PBN and rated on severity of the disorder. Buds at various stages of PBN were fixed for light microscopy. Cell breakdown was observed in all buds where PBN was visible. Collapse and thickening of cell walls was observed in a region of necrotic tissue and severity of PBN appeared to increase over time. The location of cell breakdown due to PBN appeared to be random and was not isolated to one region within the primary bud. PBN appeared to stop primordial growth, with cells differentiating further and maturing more rapidly without forming whole leaves. This cell region then breaks down and the necrosis can extend into the secondary buds.

Early Sowing and Irrigating of Rape Crops in Cool Temperate Environments Boosts Forage Yield Potential

Forage rape is commonly grown on Tasmanian dairy farms to provide feed during periods of low pasture growth and/or low nutritive value. In these regions, forage crops are generally sown between early spring and late autumn and are commonly rainfed, though farmers may apply a single irrigation at sowing. While the effect of water availability on forage yield has been well characterised for regions in north-western Tasmania (Neilsen 2005), there is a dearth of information for other regions in Tasmania. Hence, the objectives of this study were to identify optimal sowing times for, and determine the extent to which a single irrigation at sowing influences productivity of, rainfed brassica crops across the dairy regions of Tasmania

Impact of Grazing on the Silage Yield of Forage Oat Crops

Winter forage oat crops are increasing in acreage on Tasmanian dairy farms. Such crops can be grazed multiple times during vegetative development in winter then later harvested for silage at the booting or soft dough growth stages in spring. Although effects of grazing on grain yield of winter cereal crops have been well characterised (Harrison et al. 2011), little research has been conducted on the influence of grazing on the forage and silage yield potential of oats grown in Tasmania. We aimed to explore the influence of grazing management on the yields of forage for grazing and ensiling of oat crops using a biophysical crop model

Effect of Nitrogen Fertiliser Applications on Botanical Composition

The diminishing returns associated with nitrogen (N) fertiliser use over time are well recognised, as are the detrimental effect to the environment of excess N fertiliser use (Eckard 1998). However, many Tasmanian dairy farmers apply continually high rates of N fertiliser (e.g. in excess of 500 kg/ha annually) to minimise risk associated with variable pasture dry matter (DM) yields, and this often occurs at the expense of white clover populations within the pasture (Frame 1990; Frame et al. 1998). The responses of botanical composition and perennial ryegrass DM yields to N fertiliser application rate were investigated in the current field plot study, to provide further information for farmers about the production-related effects of their N use

Effect of Defoliation Management on Expression of the ‘High Sugar’ Cultivar Trait in Tasmania

The proposed benefits of perennial ryegrass (Lolium perenne L.) cultivars with a high concentration of water soluble carbohydrates (WSC) for the dairy industry in Australia include enhanced rumen protein metabolism, and potential improvements in milk components (Stewart et al. 2009). Perennial ryegrass cultivars have been developed to express higher levels of WSC, and extensive trials have shown consistent trait expression in Europe (reviewed by Edwards et al. 2007a). In New Zealand and Australia, there has been less consistent expression of the high sugar trait (Smith et al. 1998; Parsons et al. 2004; Francis et al. 2006), possibly reflecting a genotype by environmental interaction (Parsons et al. 2007). The current study was developed to investigate whether the high sugar trait of cultivars Aber-Magic (developed in Aberystwyth) and SF Joule AR1 (developed in Australia), is consistently expressed in cool temperate Tasmania, Australia, and to quantify the effect of contrasting defoliation management on trait expression. It is also important to confirm that any elevation in WSC concentration does not occur at the expense of dry matter (DM) yield, and to consider the relationship between WSC and crude protein (CP) concentrations - thought to be an important contributor to more efficient nitrogen (N) partitioning (Edwards et al. 2007b)

Modelling the resilience of forage crop production to future climate change in the dairy regions of southeastern Australia using APSIM

A warmer and potentially drier future climate is likely to influence the production of forage crops on dairy farms in The southeast dairy regions of Australia. Biophysical modelling was undertaken to explore the resilience of forage production of individual forage crops to scalar increases in temperature, atmospheric carbon dioxide (CO2) concentration and changes in daily rainfall. The model APSIM was adapted to reflect species specific responses to growth under elevated atmospheric CO2 concentrations. It was then used to simulate 40 years of production of forage wheat, oats, annual ryegrass, maize grown for silage, forage sorghum, forage rape and alfalfa grown at three locations in southeast Australia with increased temperature scenarios (1, 2, 3 and 4 °C of warming) and atmospheric CO2 concentration (435, 535, 640 and 750 ppm) and decreasing rainfall scenarios (10, 20 or 30% less rainfall). At all locations positive increases in DM yield compared with the baseline climate scenario were predicted for lucerne (2·6–93·2% increase), wheat (8·9-37·4% increase), oats (6·1–35·9% increase) and annual ryegrass (9·7–66·7% increase) under all future climate scenarios. The response of forage rape and forage sorghum varied between location and climate change scenario. At all locations, maize was predicted to have a minimal change in yield under all future climates (between a 2·6% increase and a 6·8% decrease). The future climate scenarios altered the seasonal pattern of forage supply for wheat, oats and lucerne with an increase in forage produced during winter. The resilience of forage crops to climate change indicates that they will continue to be an important component of dairy forage production in southeastern Australia

Geometric quantization of completely integrable Hamiltonian systems in the action-angle variables

We provide geometric quantization of a completely integrable Hamiltonian system in the action-angle variables around an invariant torus with respect to polarization spanned by almost-Hamiltonian vector fields of angle variables. The associated quantum algebra consists of functions affine in action coordinates. We obtain a set of its nonequivalent representations in the separable pre-Hilbert space of smooth complex functions on the torus where action operators and a Hamiltonian are diagonal and have countable spectra.Comment: 8 page

Coherent states for Hopf algebras

Families of Perelomov coherent states are defined axiomatically in the context of unitary representations of Hopf algebras possessing a Haar integral. A global geometric picture involving locally trivial noncommutative fibre bundles is involved in the construction. A noncommutative resolution of identity formula is proved in that setup. Examples come from quantum groups.Comment: 19 pages, uses kluwer.cls; the exposition much improved; an example of deriving the resolution of identity via coherent states for SUq(2) added; the result differs from the proposals in literatur

Climate change effects on pasture-based dairy systems in south-eastern Australia

Increases in temperature, along with possible decreases in rainfall will influence the production of forage on Australian dairy farms. A biophysical simulation study was undertaken to compare the performance of perennial pastures and annual forage cropping systems under historical and two possible future climate scenarios for three key dairy locations of south-eastern Australia. Pastures and forage cropping systems were simulated with the biophysical models DairyMod and APSIM, respectively for a location with a heavy reliance on irrigation (Dookie, Victoria), a location with a partial reliance on irrigation (Elliott, Tasmania) and a dryland location (Terang, Victoria). The historical climate scenario (baseline scenario) had no augmentation to climate data and an atmospheric CO2 concentration of 380 ppm, while the two future climate scenarios had either a 1oC increase in temperatures (with an atmospheric CO2 concentration of 435 ppm) and a concurrent 10% decrease in rainfall (+1/-10 scenario) or a 2oC increase in temperatures (with an atmospheric CO2 concentration of 535 ppm) and a concurrent 20% decrease in rainfall and (+2/-20 scenario). Mean annual dry matter (DM) yields (t DM/ha) at Dookie of the forage cropping options and the pasture systems increased under both the future climate scenarios but more irrigation was required. At Terang, the forage cropping systems increased yield while the yield of the pasture systems decreased under the future climate senarious. At Elliott, irrigated pastures and cropping systems increase yield while there was minimal or a negative impact on dryland pastures and cropping systems yields under the futre climate senarious. At all three locations forage production in the colder months of the year increased with a decrease in production during the warmer months. This study indicates that double cropping and irrigated pasture systems at all three locations appear resilient to projected changes in climate, however, for irrigated systems this assumes a reliable supply of irrigation water. The systems implications of how a shift in the seasonality of forage supply within these options impacts on the farm system as a whole warrants further investigation

Alignment of the ISAC-II Medium Beta Cryomodule with a Wire Monitoring System

Publisher Summary This chapter discusses a system that has been designed to monitor changes in the alignment of the cavities and solenoids during pump out and cool down. TRIUMF is developing ISAC-II, a superconducting (SC) linac. It will comprise 9 cryomodules with a total of 48 niobium cavities and 12 SC solenoids. They must remain aligned at liquid He temperatures: cavities to ±400 μm and solenoids to ±200 μm after a vertical contraction of ∼4 mm. A wire position monitor (WPM) system based on a TESLA design measures the signals induced in stripline pickups by a 215 MHz signal carded by a position reference wire. The sensors, one per cavity and two per solenoid, monitor their motion during pre-alignment, pumping, and cool down. System accuracy is ∼7 μm. The device is giving a wealth of information over and above the data collected with the installed optical targets. The use of optical targets involves personnel and the readings can be taken only periodically. Conversely the WPM data is monitored continuously providing detailed data that is extremely valuable to help characterize a new structure