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McRae J.M.,Australian Wine Research Institute | Dambergs R.G.,Australian Wine Research Institute | Dambergs R.G.,Tasmanian Institute of Agriculture | Kassara S.,Australian Wine Research Institute | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

The phenolic composition of red wine impacts upon the color and mouthfeel and thus quality of the wine. Both of these characteristics differ depending on the age of a wine, with the purple of young wines changing to brick red and the puckering or aggressive astringency softening in older wines. This study investigated the color parameters, tannin concentrations and tannin composition of a 50 year series of Cabernet Sauvignon wines from a commercial label as well as 30 year series of Cabernet Sauvignon and Shiraz wines from a separate commercial label to assess the impact of wine age on phenolic composition and concentration. The wine color density in wines of 40 to 50 years old was around 5 AU compared with 16 AU of wine less than 12 months old, which correlated well with the concentration of non-bleachable pigments and pigmented polymers. Conversely, the anthocyanin concentrations in 10 year old wines were substantially lower than that of recently bottled wines (around 100 mg/L compared with 627 mg/L, respectively), adding further evidence that non-bleachable pigments including pigmented polymers play a much larger role in long-term wine color than anthocyanins. No age-related trend was observed for tannin concentration, indicating that the widely noted softer astringency of older red wines cannot necessarily be directly related to lower concentrations of soluble wine tannin and is potentially a consequence of changes in tannin structure. Wine tannins from older wines were generally larger than tannins from younger wines and showed structural changes consistent with oxidation. © 2012 American Chemical Society.


Harrison M.T.,French National Institute for Agricultural Research | Harrison M.T.,University of Queensland | Harrison M.T.,Tasmanian Institute of Agriculture | Tardieu F.,French National Institute for Agricultural Research | And 3 more authors.
Global Change Biology | Year: 2014

Global climate change is predicted to increase temperatures, alter geographical patterns of rainfall and increase the frequency of extreme climatic events. Such changes are likely to alter the timing and magnitude of drought stresses experienced by crops. This study used new developments in the classification of crop water stress to first characterize the typology and frequency of drought-stress patterns experienced by European maize crops and their associated distributions of grain yield, and second determine the influence of the breeding traits anthesis-silking synchrony, maturity and kernel number on yield in different drought-stress scenarios, under current and future climates. Under historical conditions, a low-stress scenario occurred most frequently (ca. 40%), and three other stress types exposing crops to late-season stresses each occurred in ca. 20% of cases. A key revelation shown was that the four patterns will also be the most dominant stress patterns under 2050 conditions. Future frequencies of low drought stress were reduced by ca. 15%, and those of severe water deficit during grain filling increased from 18% to 25%. Despite this, effects of elevated CO2 on crop growth moderated detrimental effects of climate change on yield. Increasing anthesis-silking synchrony had the greatest effect on yield in low drought-stress seasonal patterns, whereas earlier maturity had the greatest effect in crops exposed to severe early-terminal drought stress. Segregating drought-stress patterns into key groups allowed greater insight into the effects of trait perturbation on crop yield under different weather conditions. We demonstrate that for crops exposed to the same drought-stress pattern, trait perturbation under current climates will have a similar impact on yield as that expected in future, even though the frequencies of severe drought stress will increase in future. These results have important ramifications for breeding of maize and have implications for studies examining genetic and physiological crop responses to environmental stresses. © 2013 John Wiley & Sons Ltd.


McPhee J.E.,Tasmanian Institute of Agriculture | Neale T.,CTF Solutions | Aird P.L.,Serve Ag Pty Ltd
Biosystems Engineering | Year: 2013

Controlled traffic farming (CTF) maintains the same machinery wheel tracks in cropping fields year after year, thereby isolating the impacts of traffic compaction from the soil used for crop growth. The benefits of CTF include reduced energy use, improved soil health and crop yield, better timeliness of field operations and improved economics.The simplest adoption of CTF occurs in flat landscapes, and mildly sloping landscapes are an advantage in relation to surface drainage. The adoption of CTF in the Australian grain and cane industries has, to a large extent, been in flat to mildly sloping topographies. The Tasmanian vegetable industry faces a very different scenario, with topographies ranging from very flat, which present potential drainage issues, to steeply undulating, which present machine tracking and erosion challenges.Two significant challenges to the adoption of CTF in a vegetable and mixed cropping based industry were investigated - (1) working and track width compatibility of current equipment, and (2) farm layouts suited to steeply undulating topography.Farm layout can dictate success or failure in the adoption of CTF, with the risk of concentrated runoff and consequent erosion in wheel tracks. Mapping of representative farms in north-west Tasmania showed effective CTF layouts are possible, despite undulating topography and infrastructure challenges. The direction of run for many fields is already close to that required for CTF.Issues related to machinery aspects of this topic are covered in a companion paper (McPhee & Aird, 2013). © 2013 .


McPhee J.E.,Tasmanian Institute of Agriculture | Aird P.L.,Serve Ag Pty Ltd
Biosystems Engineering | Year: 2013

Controlled traffic farming (CTF) maintains the same machinery wheel tracks in cropping fields year after year, thereby isolating the impacts of traffic compaction from the soil used for crop growth. Benefits of CTF include improved energy efficiency, soil health, crop yield, timeliness and economics.The successful adoption of CTF in the Australian grain and cane industries has been largely based on a limited equipment suite and flat to mildly sloping topography. The Tasmanian vegetable industry faces a very different scenario, with a wide diversity of machinery, and topography ranging from gently to steeply undulating.Two key technical challenges to the adoption of CTF in vegetable and mixed cropping were investigated - 1) working and track width compatibility of current equipment, and 2) farm layouts suited to steeply undulating topography.Almost no machines are currently compatible with a common track or working width, although some are suitable for modification to enable CTF operation. Some harvest machinery (e.g. single row potato harvesters) provides few options for change. Seasonal CTF represents a possible starting place for adoption until more compatible machinery is available.Findings in relation to farm layouts are reported in a companion paper (McPhee, Neale, & Aird, 2013). © 2013 .


Measham P.F.,University of Tasmania | Wilson S.J.,University of Tasmania | Gracie A.J.,University of Tasmania | Bound S.A.,Tasmanian Institute of Agriculture
Agricultural Water Management | Year: 2014

This study explores vascular influx of water in sweet cherry (Prunus avium L.) fruit because water is a key component of fruit quality and has been implicated in cherry fruit cracking. Flow to fruit is influenced by changing water potential of the fruit, and of potential gradients between the fruit and the spur. Water potential was influenced by vapour pressure deficit. In all seasons of this study, the most negative fruit water potential occurred in mid-afternoon when the magnitude of fruit water potential (ΨF) was greater than leaf water potential (ΨL) and analysis showed that there was a significant difference in this potential gradient between days with and without rainfall. Frequency analysis of days monitored over seasons further showed a significant association between the incidence of natural or simulated rainfall and the direction of sap flow to the fruit. This implies that manipulation of the driving forces within sweet cherry trees could be a viable management strategy for the prevention of cracking in cherry fruit. Furthermore, it suggests a role for orchard irrigation, in avoiding development of water potential gradients of fruit that favour rapid vascular influx of water following rainfall. © 2014.


Jones J.E.,Tasmanian Institute of Agriculture | Lee G.,University of Tasmania | Wilson S.J.,Tasmanian Institute of Agriculture
American Journal of Enology and Viticulture | Year: 2013

A statistical model to estimate and describe bud fruitfulness in Pinot noir in cool environments was developed. The study compared Pinor noir fruitfulness at three different sites during winter dormancy by light microscopy and actual fruitfulness established three weeks after budburst. Strong differences were observed between inflorescence primordia counts and actual inflorescence number after budburst. When examined microscopically, fruitfulness was evenly distributed along the cane with the exception of the first two nodes, which were significantly lower. In contrast, actual fruitfulness after budburst showed site differences and interactions between fruitfulness and node position. Cane starch was a significant predictor for inflorescence count. © 2013 by the American Society for Enology and Viticulture. All rights reserved.


Measham P.F.,University of Tasmania | Bound S.A.,Tasmanian Institute of Agriculture | Gracie A.J.,University of Tasmania | Wilson S.J.,University of Tasmania
Advances in Horticultural Science | Year: 2012

Yield loss from rain-induced fruit cracking is a perpetual risk associated with the production of sweet cherries, and is difficult to manage due to the unpredictability of fruit responses to late season rainfall. The aim of this five-year study was to investigate the relationship between fruit crop load and incidence of cracking. The results showed a negative correlation between crop load and incidence of fruit cracking, and it was found in both natural and manipulated crop load trials for all varieties studied and in all seasons assessed. The effect of crop load on final cracking levels are determined post cell division. Results from this study showed that fruit width was positively correlated with cuticular cracking but, contrary to what has been purported in literature, no relationship between concentration of soluble sugars or firmness with the incidence of cracking was found. This study has confirmed that crop load should be a major consideration in orchard practices in developing strategies to manage fruit cracking.


Rowe B.A.,Tasmanian Institute of Agriculture | Neilsen J.E.,Tasmanian Institute of Agriculture
Crop and Pasture Science | Year: 2016

Irrigation was applied at different rates and frequencies during five consecutive periods of vegetative growth of the forage turnip Brassica rapa var. rapa cv. Barkant, grown in the field in north-west Tasmania, Australia, during the spring and summer of 1999-2000 (Season 1) and 2000-01 (Season 2). Irrigation applied before root expansion did not increase the dry matter (DM) of turnips (leaf plus root) in either season. At the following four harvests in each season, DM increased linearly in proportion to the cumulative amount of irrigation applied before the harvests. Irrigation water use efficiency, as measured by the slopes of the linear regressions, ranged from 5.7 to 17.2kgDMha-1mm-1 in Season 1 and from 19.2 to 26.0kgDMha-1mm-1 in Season 2. The effective use of water (EUW; yield increase/evapotranspiration within a period) was calculated for each of the five periods in Season 2 to identify the vegetative growth periods when the response (kgDMha-1mm-1) was greatest and limited irrigation water could be applied most effectively. EUW of irrigated turnip increased from 16.8kgDMha-1mm-1 at the onset of root expansion to 53.5kgDMha-1mm-1 when root growth rate was a maximum, but declined thereafter. Scarce irrigation should be applied between the onset of root expansion and approximately 8 weeks later, when the response to irrigation (kgDMha-1mm-1) was greatest. © CSIRO 2016.


Alcock D.J.,Graz Prophet Consulting | Harrison M.T.,Tasmanian Institute of Agriculture | Rawnsley R.P.,Tasmanian Institute of Agriculture | Eckard R.J.,University of Melbourne
Agricultural Systems | Year: 2015

Farm intervention strategies that reduce greenhouse gas (GHG) emissions from the livestock industries may reduce global emissions associated with agriculture, though farmers are unlikely to adopt new practises unless they also improve farm profitability. Here our objective was to explore the effect of manipulating enterprise management or animal genotype on whole-farm production, profitability, enteric methane emissions and wool emissions intensities of sheep enterprises in southern Australia. Two enterprises that differed in lamb sale age were simulated using the model GrassGro; surplus animals were sold at either 18weeks (weaner) or 12months old (yearling). We examined the influence of lambing time (LT), joining maiden ewes at 7months instead of 19months of age (JA), increasing lamb weaning rates (WR), or superior genotypes with 10% improvement in fleece weight (FW), feed efficiency (FE) and/or methane yield (MY).Annual wool production, methane emissions, wool emissions intensities and profitability averaged across the baseline enterprises were 55kg clean wool/ha, 3.2tCO2-eq/ha, 31kgCO2-eq/kg clean wool and $569/ha. Relative to these values average profitability increased by up to 18%, 15%, 10%, 9%, 8% and 0% for the JA, WR, FW, FE, LT and MY strategies; associated changes in wool production were 0%, -3%, 11%, 0%, 2% and 0%, and wool emissions intensities changed by -4%, -8%, -5%, -7%, 0% and -10%, respectively.Increasing weaning rate and introducing genotypes with lower methane yield afforded the greatest reductions in wool emissions intensities. Divergence between the relative effects of alternative strategies on farm economics, production and wool emissions intensities suggests that farm adaptations will depend on the goal of the individual farmer. If the goal is to increase profitability, flock management interventions are most beneficial; if the goal is to reduce emissions intensity, superior breeds containing improvements in several genetic traits have the greatest potential. We demonstrate that no intervention - to farm management, animal genotype or otherwise - is likely to achieve simultaneous improvements in all of production, profitability, net farm emissions and wool emissions intensity. Under current carbon prices, subsidies greater than $150/tCO2-eq would be required if economic returns from GHG abatement were to equal those from increased productivity, suggesting there would be little incentive for wool producers to participate in the Carbon Farming Initiative under the intervention strategies modelled here. © 2014 Elsevier Ltd.


Dambergs R.G.,Australian Wine Research Institute | Dambergs R.G.,Tasmanian Institute of Agriculture | Mercurio M.D.,Australian Wine Research Institute | Kassara S.,Australian Wine Research Institute | And 2 more authors.
Applied Spectroscopy | Year: 2012

Information relating to tannin concentration in grapes and wine is not currently available simply and rapidly enough to inform decision-making by grape growers, winemakers, and wine researchers. Spectroscopy and chemometrics have been implemented for the analysis of critical grape and wine parameters and offer a possible solution for rapid tannin analysis. We report here the development and validation of an ultraviolet (UV) spectral calibration for the prediction of tannin concentration in red wines. Such spectral calibrations reduce the time and resource requirements involved in measuring tannins. A diverse calibration set (n = 204) was prepared with samples of Australian wines of five varieties (Cabernet Sauvignon, Shiraz, Merlot, Pinot Noir, and Durif), from regions spanning the wine grape growing areas of Australia, with varying climate and soils, and with vintages ranging from 1991 to 2007. The relationship between tannin measured by the methyl cellulose precipitation (MCP) reference method at 280 nm and tannin predicted with a multiple linear regression (MLR) calibration, using ultraviolet (UV) absorbance at 250, 270, 280, 290, and 315 nm, was strong (r 2val=0.92; SECV=0.20 g/L). An independent validation set (n = 85) was predicted using the MLR algorithm developed with the calibration set and gave confidence in the ability to predict new samples, independent of the samples used to prepare the calibration (r 2val = 0.94; SEP = 0.18 g/L). The MLR algorithm could also predict tannin in fermenting wines (r 2val=0.76; SEP=0.18 g/L), but worked best from the second day of ferment on. This study also explored instrument-to-instrument transfer of a spectral calibration for MCP tannin. After slope and bias adjustments of the calibration, efficient calibration transfer to other laboratories was clearly demonstrated, with all instruments in the study effectively giving identical results on a transfer set. © 2012 Society for Applied Spectroscopy.

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