South Australian Research And Development Institute

Adelaide, Australia

South Australian Research And Development Institute

Adelaide, Australia

The South Australian Research and Development Institute is a state government funded institute with locations throughout South Australia. SARDI is part of Primary Industries and Resources South Australia Wikipedia.

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Sadras V.O.,South Australian Research And Development Institute | Lemaire G.,French National Institute for Agricultural Research
Field Crops Research | Year: 2014

The nitrogen economy of the crop is a critical driver of biomass and grain production, and its importance is reflected in a large, worldwide research effort to link nitrogen, growth and yield. Particular research questions require measurement of specific traits, hence the need to quantify multiple, often complementary traits including crop nitrogen uptake, nitrogen use efficiency and its components, nitrogen concentration in the crop and its parts, down to relevant enzymes (e.g. nitrate reductase) and other products of gene expression. Nitrogen uptake, however, is co-regulated by both soil nitrogen availability and crop biomass accumulation; hence, crop nitrogen uptake or shoot nitrogen concentration reflect univocally crop nitrogen status only if comparisons are made at similar biomass. Although the allometric relationships between biomass and nitrogen uptake have been established for over two decades, many studies still report results in terms of nominal treatments, e.g. high vs low nitrogen, which are uninformative; curves relating yield and fertiliser rate, which are of local interest but provide little insight on the underlying processes and have low generic value; and nitrogen-related traits that are incomplete or inadequate to quantify crop nutrition status. Often, the allometric relationships between nitrogen and biomass are overlooked. In this opinion paper, we summarise the already well established concepts of dilution curves and nitrogen nutrition index, outline the standard partitioning of nitrogen use efficiency, and highlight the confounded effects in nitrogen use efficiency when the allometric relationship between nitrogen uptake and biomass is ignored. A sample of recent papers is used to survey the most common approaches to characterise nitrogen related traits. We illustrate the application of dilution curves and nitrogen nutrition index in the assessment and interpretation of crop responses to agronomic practices and comparisons of wheat cultivars and maize hybrids. © 2014 Elsevier B.V.

Bradshaw C.J.A.,University of Adelaide | Bradshaw C.J.A.,South Australian Research And Development Institute
Journal of Plant Ecology | Year: 2012

Aims: Australia is among one of the world's wealthiest nations; yet, its relatively small human population (22.5 million) has been responsible for extensive deforestation and forest degradation since European settlement in the late 18th century. Despite most (∼75%) of Australia's 7.6 million-km 2 area being covered in inhospitable deserts or arid lands generally unsuitable to forest growth, the coastal periphery has witnessed a rapid decline in forest cover and quality, especially over the last 60 years. Here I document the rates of forest loss and degradation in Australia based on a thorough review of existing literature and unpublished data. Important Findings: Overall, Australia has lost nearly 40% of its forests, but much of the remaining native vegetation is highly fragmented. As European colonists expanded in the late 18th and the early 19th centuries, deforestation occurred mainly on the most fertile soils nearest to the coast. In the 1950s, southwestern Western Australia was largely cleared for wheat production, subsequently leading to its designation as a Global Biodiversity Hotspot given its high number of endemic plant species and rapid clearing rates. Since the 1970s, the greatest rates of forest clearance have been in southeastern Queensland and northern New South Wales, although Victoria is the most cleared state. Today, degradation is occurring in the largely forested tropical north due to rapidly expanding invasive weed species and altered fire regimes. Without clear policies to regenerate degraded forests and protect existing tracts at a massive scale, Australia stands to lose a large proportion of its remaining endemic biodiversity. The most important implications of the degree to which Australian forests have disappeared or been degraded are that management must emphasize the maintenance of existing primary forest patches, as well as focus on the regeneration of matrix areas between fragments to increase native habitat area, connectivity and ecosystem functions. © 2012 The Author. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China. All rights reserved.

Sadras V.O.,South Australian Research And Development Institute | Petrie P.R.,Treasury Wine Estates Ltd.
Australian Journal of Grape and Wine Research | Year: 2011

Background and Aim: Early maturity of grape crops associated with recent warming is well documented but poorly understood. Here, we ask the question: is early maturity associated with early onset of ripening or with increased rate of sugar accumulation? Methods and Results: We used records of grape juice total soluble solids (TSS) for Chardonnay, Shiraz and Cabernet Sauvignon collected in commercial vineyards between 1995 and 2009. The combination of 15 vintages and three climatic regions yielded a range of average seasonal temperature between 15.5 and 20.5°C. Using boundary functions of TTS versus time, we derived the onset and rate of increase in TSS, and the time of maturity set at 12 °Bé for comparative purposes. Pooled across varieties, the rate of change in maturity was -9.8±0.94°C/d. Shifts in onset accounted for 86% of the variation in time of maturity and the rate of ripening for the remaining variation. Conclusion: Early maturity associated with higher temperature (and related factors including higher radiation and higher vapour pressure deficit) is primarily driven by early onset of ripening under a wide range of production systems in south-eastern Australia. Significance of the Study: Viticultural practices aiming at delaying maturity to counteract the effect of high temperature, high radiation and high vapour pressure deficit are more likely to be successful if they target the onset of ripening. © 2011 Australian Society of Viticulture and Oenology Inc.

Howie J.H.,South Australian Research And Development Institute
Crop and Pasture Science | Year: 2012

Boron (B) is present at toxic levels in the subsoils of much of the semiarid south-eastern Australian cereal-livestock zone. Boron toxicity is typically associated with alkaline soils, where annual medics (Medicago spp.) are generally the best-adapted pasture legume. New medic cultivars have been developed for which there is no published B tolerance information. Five species of annual medic represented by 13 cultivars were grown in soil amended with B and evaluated for B tolerance. A rating system based on expression of symptoms was modified from earlier research. There was a wide range of response to B, both between and within species. Cultivars varied widely in their expression of symptoms; from showing no or few leaf symptoms (tolerant) to significant leaf necrosis (very sensitive). An integrated summary of both published and previously, unpubl. data for these and other medics is presented to provide a comprehensive and up-to-date comparison between different species and most commercial cultivars. This information will be useful for plant breeders, agronomists and farmers who manage soils with high B levels. Journal compilation © CSIRO 2012.

Sadras V.O.,South Australian Research And Development Institute | Richards R.A.,CSIRO
Journal of Experimental Botany | Year: 2014

Crop yield in dry environments can be improved with complementary approaches including selecting for yield in the target environments, selecting for yield potential, and using indirect, trait- or genomic-based methods. This paper (i) outlines the achievements of direct selection for yield in improving drought adaptation, (ii) discusses the limitations of indirect approaches in the context of levels of organization, and (iii) emphasizes trade-offs and synergies between nitrogen nutrition and drought adaptation. Selection for yield in the water- and nitrogen-scarce environments of Australia improved wheat yield per unit transpiration at a rate of 0.12kg ha-1 mm-1 yr-1; for indirect methods to be justified, they must return superior rates of improvement, achieve the same rate at lower cost or provide other cost-effective benefits, such as expanding the genetic basis for selection. Slow improvement of crop adaptation to water stress using indirect methods is partially related to issues of scale. Traits are thus classified into three broad groups: those that generally scale up from low levels of organization to the crop level (e.g. herbicide resistance), those that do not (e.g. grain yield), and traits that might scale up provided they are considered in a integrated manner with scientifically sound scaling assumptions, appropriate growing conditions, and screening techniques (e.g. stay green). Predicting the scalability of traits may help to set priorities in the investment of research efforts. Primary productivity in arid and semi-arid environments is simultaneously limited by water and nitrogen, but few attempts are made to target adaptation to water and nitrogen stress simultaneously. Case studies in wheat and soybean highlight biological links between improved nitrogen nutrition and drought adaptation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Bice C.M.,South Australian Research And Development Institute | Zampatti B.P.,South Australian Research And Development Institute
Ecological Engineering | Year: 2011

River regulation can advantage non-native aquatic biota at the expense of native species. Nevertheless, flow regulating structures are sometimes used with the aim of achieving positive environmental outcomes in aquatic ecosystems. In the lower River Murray, Australia, drought-induced water level recession and acid sulfate soil exposure prompted the construction of an earthen levee, isolating a section of river channel (the Goolwa weir pool (GWP)) within which water levels were managed to mitigate a risk of water body acidification. The present study aimed to determine the impact of water level management on the fish community by investigating variation in species abundance and recruitment between sites subject to water level management in the GWP and unmanaged sites in Lake Alexandrina. Prior to levee construction, in August 2009, the abundance of the non-native common carp was similar in the GWP and Lake Alexandrina. Following water level management, in December 2009 and April 2010, the abundance of common carp in the GWP was approximately 1000 and 250 times greater than abundance in Lake Alexandrina, as a result of recruitment of young-of-year fish. No native freshwater species were significantly more abundant in the GWP in August 2009, December 2009 or April 2010. The results of this study suggest that the isolation of a river reach and a managed rise in water level facilitated spawning and recruitment of a non-native fish species. As such, the ecological benefits and risks of restoration and mitigation projects that involve the construction of flow regulating structures and water level management should be carefully considered. © 2011 Elsevier B.V.

Sadras V.O.,South Australian Research And Development Institute | Lawson C.,South Australian Research And Development Institute
European Journal of Agronomy | Year: 2013

We used a collection of Australian wheats released between 1958 and 2007 to probe for time trends in evapotranspiration and nitrogen uptake, and the efficiencies in the use of water and nitrogen to produce grain yield. Yield increased linearly with year of cultivar release at a rate of 18kgha-1y-1; this rate aligned with the relationship between rate of genetic gain and environmental yield from breeding programs worldwide. No time trend was apparent for seasonal evapotranspiration, hence the linear increase in yield per unit evapotranspiration with year of release which was fully accounted for by yield improvement. Under our experimental conditions, yield per unit transpiration of current varieties was ∼24kgha-1mm-1, highlighting the need to update the 20kgha-1mm-1 ratio commonly used in agronomic benchmarking. Yield per unit nitrogen uptake was largely unchanged as a consequence of increased nitrogen uptake that paralleled the increase in yield, and a secondary contribution of reduced grain protein concentration particularly under environmental conditions that favoured high protein. The nitrogen nutrition index, accounting for the effect of biomass on nitrogen uptake, increased linearly with year of cultivar release, hence supporting the conclusion that breeding for yield improved the nutrition status of wheat in association with an increased capacity to uptake nitrogen in equal-sized crops. © 2012 Elsevier B.V.

Sadras V.O.,South Australian Research And Development Institute | Moran M.A.,South Australian Research And Development Institute
Australian Journal of Grape and Wine Research | Year: 2012

Background and Aim: We tested the hypothesis that elevated temperature decouples anthocyanins and total soluble solids (TSS) in developing berries and explored the effects of fruit load and water supply on the putative decoupling. Methods and Results: We established three 22 factorial experiments where two thermal regimes (elevated temperature, control) where combined with varieties (Shiraz, Cabernet Franc), fruit loads (bunch removal, control) or water regimes (irrigated, water deficit). The relationship between anthocyanins and TSS had a lag phase where TSS increased with no change in anthocyanins and an approximately linear phase where both traits increased in parallel for TSS>11.4°Brix. Mean residuals in the linear phase were 0.065mg/g in controls compared with -0.064mg/g in the heated treatment, hence demonstrating the thermal decoupling of anthocyanins and TSS across varieties fruit loads and water regimes (P<0.0001). Delayed onset of anthocyanin accumulation at elevated temperature explained the decoupling. Water deficit increased the anthocyanin:TSS ratio. Conclusion: Elevated temperature decoupled anthocyanins and sugars in berries by a relative shift in onset rather than rate of accumulation of these berry components. Significance of the Study: Warming trends are likely to disrupt the anthocyanin:sugar ratio in berries with consequences for colour:alcohol balance in red wines. Water deficit established shortly before veraison could partially restore these ratios. © 2012 Australian Society of Viticulture and Oenology Inc.

Latta R.A.,South Australian Research And Development Institute
Crop and Pasture Science | Year: 2015

In mixed cropping and livestock dryland farming systems in southern Australia, grazing of cereals during their vegetative growth stages (typically during winter) can provide a valuable contribution of high-quality feed during a period of low pasture growth. This paper reports results from a series of experiments investigating the impact of defoliation on the grain production of cereals in the Eyre Peninsula region of South Australia. The comparative dry matter production and grain yield of wheat, barley and oats cultivars, with and without defoliation, at a range of growth stages were measured in four experiments over three growing seasons, two of which were water-deficient. The barley varieties evaluated produced up to twice the dry matter of the wheat or oats cultivars to the time of defoliation. Mowing following stem elongation more than halved grain yield (1.9 to 0.9tha-1) relative to no defoliation in an early-maturing variety, but with less reduction in later maturing varieties. Defoliation before stem elongation in two seasons of very low growing-season rainfall (<100mm) caused no or very little loss in grain yields, which were generally <1tha-1. A long-season winter wheat produced similar grain yields irrespective of defoliation and timing, but with no yield advantage over the defoliated spring cereals. The results suggest opportunities to incorporate the grazing of cereals to fill a winter feed-gap in the low-rainfall zone of southern Australia. © 2015 CSIRO.

Mayfield S.,South Australian Research And Development Institute
Fisheries Research | Year: 2010

Effective management of commercial fisheries is dependent on the reliability of fishery assessments that, in turn, are determined by the quantity and quality of the available data. Data on the length-structure of the catch provide important information on exploited stocks, but representative sub-sampling is difficult to achieve, especially where numerous licence holders fish over large areas. This study evaluates the potential for routinely collected, commercial, weight-grade data to overcome this challenge and enhance assessment of the Western Zone blacklip (Haliotis rubra) and greenlip (Haliotis laevigata) abalone fisheries in South Australia. Current weight-grade data for blacklip abalone are inaccurate. However, the accuracy, rigour and consistency of the data for greenlip abalone confirm they are sufficiently reliable for aiding fishery assessments on this species. The greenlip abalone data were highly representative of the catch and the fishery and have been obtained in a consistent manner for >20 years. Changes in the composition of the grades in the catch provide a meaningful measure of change in the harvested stock. Similarly, measures of mean weight and number harvested, derived from the weight-grade data, are valuable as additional indices of stock status. These attributes substantially enhance the credibility of these data for use in assessing changes in stock status through time, and suggest these data should be used to supplement current assessments of this species. The value of the weight-grade data would increase substantially if the resolution was improved by using automated weighing and grading systems. The analysis of weight-grade data, routinely collected from numerous fisheries, is likely to benefit their assessment. © 2010 Elsevier B.V.

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