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Zeleke K.T.,Charles Sturt University | Luckett D.J.,Graham Center for Agricultural Innovation
Agronomy Journal | Year: 2017

Canola (Brassica napus L.) is a major temperate crop in Australia, and there is a dynamic commercial breeding industry producing new cultivars for growers. Improved stress tolerance in canola cultivars is of increasing importance, but it is difficult to detect and to breed for. Public-sector researchers need reliable information on which existing cultivars possess good stress tolerance and can be used as germplasm sources for traits worthy of pre-breeding research. We utilized the Australian National Variety Trial (NVT) data for released canola cultivars to examine two aspects of canola performance. First, the stress tolerance of cultivars was examined using low-yielding vs. high-yielding environments. Second, the genotype × environment interactions of cultivars were investigated and whether or not they exhibited significant crossover interaction, indicating general or specific adaptation. The NVT dataset consisted of results for 144 cultivars tested over 7 yr (2008–2014) at 101 locations and in 782 field plot experiments. Large differences in stress tolerance were seen in the data, and certain cultivars are recommended as candidates for further investigation. Many cultivars showed genotype × environment crossover interactions, indicating specific rather than general adaptation, although a few exceptional cultivars were high yielding and stable. © 2017 by the American Society of Agronomy.

Emebiri L.C.,Graham Center for Agricultural Innovation | Oliver J.R.,Graham Center for Agricultural Innovation | Mrva K.,University of Adelaide | Mares D.,University of Adelaide
Molecular Breeding | Year: 2010

Late maturity α-amylase (LMA) is a genetic defect of wheat which results in the production of α-amylase, shown as substandard falling numbers, in the absence of preharvest rain and under cool temperatures during ripening. The present study is an attempt to use a whole-genome scan with DArT markers to identify chromosomal regions influencing LMA in synthetic hexaploid wheat (SHW). A high heritability estimate of 86.6% was calculated for LMA phenotype measured as optical density in a collection of 91 SHWs. Linkage disequilibrium extended up to 10 cM, and with controls for false positives, significant markers were detected at the chromosome 7B region previously linked to LMA in bread wheat, but not at the chromosome 3B region. Of potentially great interest is a region on chromosome 6B, which was identified as having a significant association with LMA phenotypes in the SHW accessions. Previous investigations suggested existence of an LMA gene on the long arm of 6B, but this is the first time it has been mapped to lie within the centromeric region of chromosome 6B, a region that harbours the Amy-1 genes and whose expression governs activity of the high pI α-amylase isoenzymes. © 2010 Springer Science+Business Media B.V.

Bellis G.A.,Fisheries and Forestry | Dyce A.L.,CSIRO | Gopurenko D.,Australian Department of Primary Industries and Fisheries | Gopurenko D.,Graham Center for Agricultural Innovation | Mitchell A.,College Street
Zootaxa | Year: 2013

The Immaculatus Group of Culicoides encompassing four species from Australia, New Caledonia, Fiji, Solomon Islands, New Guinea and the Malay archipelago is revised. A diagnosis for the group, descriptions of males and females of C. shivasi sp. n. and C. collessi sp. n., a description of the male of C. immaculatus Lee & Reye, a redescription of the female of C. immaculatus and a diagnosis of C. agas Wirth & Hubert together with keys for their specific determination are presented. Specific separation of the morphologically similar C. shivasi and C. immaculatus is supported by DNA barcodes (mitochondrial cytochrome oxidase I or COI) and nuclear carbomoylphosphate synthetase (CAD) sequence data. Copyright © 2013 Magnolia Press.

Moody P.W.,Science Delivery | Speirs S.D.,Graham Center for Agricultural Innovation | Scott B.J.,Charles Sturt University | Mason S.D.,University of Adelaide
Crop and Pasture Science | Year: 2013

The phosphorus (P) status of 535 surface soils from all states of Australia was assessed using the following soil P tests: Colwell-P (0.5m NaHCO3), Olsen-P (0.5m NaHCO3), BSES-P (0.005m H2SO4), and Mehlich 3-P (0.2m CH3COOH+0.25m NH4NO3+0.015m NH4F+0.013m HNO3+0.001m EDTA). Results were correlated with soil P assays selected to estimate the following: soil solution P concentration (i.e. 0.01m CaCl2 extractable P; Colwell-P/P buffer index); rate of P supply to the soil solution (i.e. P released to FeO-impregnated filter paper); sorbed P (i.e. Colwell-P); mineral P (i.e. fertiliser reaction products and/or soil P minerals estimated as BSES-P minus Colwell-P); the diffusive supply of P (i.e. P diffusing through a thin gel film, DGT-P); and P buffer capacity (i.e. single-point P buffer index corrected for Colwell-P, PBICol). Across all soils, Colwell-P and BSES-P were highly correlated with FeO-P (r≤0.76 and 0.58, respectively). Colwell-P was moderately correlated with mineral P (r≤0.24), but not solution P. Olsen-P and Mehlich-P were both highly correlated with FeO-P (r≤0.80 and 0.78, respectively) but, in contrast to Colwell-P and BSES-P, also showed moderate correlations with soil solution P (r≤0.29 and 0.34, respectively) and diffusive P supply (r≤0.31 and 0.49, respectively). Correlation coefficients with mineral P were r≤0.29 for Olsen-P and r≤0.17 for Mehlich-P. Soils were categorised according to their pH, clay activity ratio, content of mineral P and CaCO3 content, and the relationships between the empirical soil P tests examined for each soil category. Olsen-P and Colwell-P were correlated across all soil categories (r range 0.66-0.90), and a widely applicable linear equation was obtained for converting one soil test to the other. However, the correlations between other soil tests varied markedly between soil categories and it was not possible to develop such widely applicable conversion equations. Multiple step-up linear regressions were used to identify the key soil properties affecting soil solution P, P buffer capacity, and diffusive P supply, respectively. For all soil categories, solution P concentration (measured by CaCl2-P) increased as rate of P supply (measured as FeO-P) increased and P buffer capacity decreased. As an assay of sorbed P, Colwell-P alone did not significantly (P>0.05) explain any of the variability in soil solution P, but when used in the index (Colwell-P/P buffer index), it was highly correlated (r≤0.74) with CaCl2-P. Soil P buffer capacity was dependent on different properties in different soil categories, with 45-65% of the variation in PBI accounted for by various combinations of Mehlich-Al, Mehlich-Fe, total organic C, clay content, clay activity ratio, and CaCO3 content, depending on soil category. The diffusive supply of P was primarily determined by rate of P supply (measured as FeO-P; r range 0.34-0.49), with significant (P<0.05) small improvements due to the inclusion of PBICol and/or clay content, depending on soil category. For these surface soil samples, key properties of pH, clay activity ratio, clay content, and P buffer capacity varied so widely within individual Australian Soil Orders that soil classification was not useful for inferring intrinsic surface soil P properties such as P buffer capacity or the relationships between soil P tests. © CSIRO 2013.

Speirs S.D.,Graham Center for Agricultural Innovation | Scott B.J.,Graham Center for Agricultural Innovation | Moody P.W.,Science Delivery | Mason S.D.,University of Adelaide
Crop and Pasture Science | Year: 2013

The performance of a wide range of soil phosphorus (P) testing methods that included established (Colwell-P, Olsen-P, BSES-P, and CaCl2-P) and more recently introduced methods (DGT-P and Mehlich 3-P) was evaluated on 164 archived soil samples corresponding to P fertiliser response experiments with wheat (Triticum aestivum) conducted in south-eastern Australia between 1968 and 2008. Soil test calibration relationships were developed for relative grain yield v. soil test using (i) all soils, (ii) Calcarosols, and (iii) all 'soils other than Calcarosols'. Colwell-P and DGT-P calibration relationships were also derived for Calcarosols and Vertosols containing measureable CaCO3. The effect of soil P buffer capacity (measured as the single-point P buffer index corrected for Colwell-P, PBICol) on critical Colwell-P values was assessed by segregating field sites based on their PBICol class: very very low (15-35), very low (36-70), low (71-140), and moderate (141-280). All soil P tests, except Mehlich 3-P, showed moderate correlations with relative grain yield (R-value ≥0.43, P<0.001) and DGT-P exhibited the largest R-value (0.55). Where soil test calibrations were derived for Calcarosols, Colwell-P had the smallest R-value (0.36), whereas DGT-P had an R-value of 0.66. For 'soils other than Calcarosols', R-values >0.45 decreased in the order: DGT-P (r≤0.55), Colwell-P (r≤0.49), CaCl2-P (r≤0.48), and BSES-P (r≤0.46). These results support the potential of DGT-P as a predictive soil P test, but indicate that Mehlich 3-P has little predictive use in these soils. Colwell-P had tighter critical confidence intervals than any other soil test for all calibrations except for soils classified as Calcarosols. Critical Colwell-P values, and confidence intervals, for the very very low, very low, and low P buffer capacity categories were within the range of other published data that indicate critical Colwell-P value increases as PBICol increases. Colwell-P is the current benchmark soil P test used in Australia and for the field trials in this study. With the exception of Calcarosols, no alternative soil P testing method was shown to provide a statistically superior prediction of response by wheat. Although having slightly lower R-values (i.e. <0.1 difference) for some calibration relationships, Colwell-P yielded tighter confidence intervals than did any of the other soil tests. The apparent advantage of DGT-P over Colwell-P on soils classified as Calcarosols was not due to the effects of calcium carbonate content of the analysed surface soils. © CSIRO 2013.

Packer E.L.,Charles Sturt University | Clayton E.H.,Australian Department of Primary Industries and Fisheries | Clayton E.H.,Graham Center for Agricultural Innovation | Cusack P.M.V.,Australian Livestock Production Services
Australian Veterinary Journal | Year: 2011

Objective To determine the prevalence of subacute rumen acidosis (SARA) in beef cattle grazing lush pasture and the effect of monensin on reducing SARA and improving animal performance. Design Commercial Angus and Murray Grey steers received a monensin slow-release capsule (n = 19) or remained untreated (n = 19). Cattle grazed an oats crop or tetraploid ryegrass pasture for a total of 91 days. Rumen fluid pH, volatile fatty acids (VFA) and lactic acid concentrations and body weight data were collected prior to treatment and again 28, 56 and 91 days after treatment. Changes in measures over time were analysed using mixed model repeated measures analysis. Differences in average daily gain between treatment groups were determined. Results The prevalence of SARA was low during the study, with only one animal satisfying criteria for SARA at one time point. Cattle treated with monensin capsules were 11.9kg heavier at the completion of the study compared with untreated controls (414.5 ± 3.88kg vs 402.6 ± 4.03kg, P = 0.04). Rumen VFA and L- and D-lactate levels did not differ between cattle treated with monensin and untreated cattle. However, the ratio of propionate to acetate plus two times butyrate was higher (P < 0.001) when cattle were treated with monensin. Conclusions Subacute rumen acidosis was not consistently detected under the conditions of the study. The higher body weight of cattle treated with monensin may have been due to improved energy utilisation of the pasture, indicated by increased propionate proportions in the rumen, rather than prevention of SARA. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Bell R.,Murdoch University | Reuter D.,Reuter and Associates | Scott B.,Graham Center for Agricultural Innovation | Sparrow L.,University of Tasmania | And 2 more authors.
Crop and Pasture Science | Year: 2013

Soil testing is the most widely used tool to predict the need for fertiliser phosphorus (P) application to crops. This study examined factors affecting critical soil P concentrations and confidence intervals for wheat and barley grown in Australian soils by interrogating validated data from 1777 wheat and 150 barley field treatment series now held in the BFDC National Database. To narrow confidence intervals associated with estimated critical P concentrations, filters for yield, crop stress, or low pH were applied. Once treatment series with low yield (<1t/ha), severe crop stress, or pHCaCl2 <4.3 were screened out, critical concentrations were relatively insensitive to wheat yield (>1t/ha). There was a clear increase in critical P concentration from early trials when full tillage was common compared with those conducted in 1995-2011, which corresponds to a period of rapid shift towards adoption of minimum tillage. For wheat, critical Colwell-P concentrations associated with 90 or 95% of maximum yield varied among Australian Soil Classification (ASC) Orders and Sub-orders: Calcarosol, Chromosol, Kandosol, Sodosol, Tenosol and Vertosol. Soil type, based on ASC Orders and Sub-orders, produced critical Colwell-P concentrations at 90% of maximum relative yield from 15mg/kg (Grey Vertosol) to 47mg/kg (Supracalcic Calcarosols), with other soils having values in the range 19-27mg/kg. Distinctive differences in critical P concentrations were evident among Sub-orders of Calcarosols, Chromosols, Sodosols, Tenosols, and Vertosols, possibly due to differences in soil properties related to P sorption. However, insufficient data were available to develop a relationship between P buffering index (PBI) and critical P concentration. In general, there was no evidence that critical concentrations for barley would be different from those for wheat on the same soils. Significant knowledge gaps to fill to improve the relevance and reliability of soil P testing for winter cereals were: lack of data for oats; the paucity of treatment series reflecting current cropping practices, especially minimum tillage; and inadequate metadata on soil texture, pH, growing season rainfall, gravel content, and PBI. The critical concentrations determined illustrate the importance of recent experimental data and of soil type, but also provide examples of interrogation pathways into the BFDC National Database to extract locally relevant critical P concentrations for guiding P fertiliser decision-making in wheat and barley. © CSIRO 2013.

Watmuff G.,Geographic Web Solutions Pty Ltd | Reuter D.J.,Reuter and Associates Pty Ltd | Speirs S.D.,Graham Center for Agricultural Innovation
Crop and Pasture Science | Year: 2013

During the past 50 years, 3800 field experiments yielding over 5200 treatment series were conducted in Australia examining yield responses to applied N, P, K, or S fertiliser applications to cereal, oilseed and pulse crops. The experiments all had accompanying soil test data. These data were entered into multiple Microsoft Access® database templates and then consolidated into a single national online MYSQL® database. A web application (named the BFDC Interrogator) was also developed to rapidly access the national database (BFDC National Database) and construct soil test calibrations between percentage of the maximum grain yield achieved (hereafter called percentage relative yield) and soil test values recorded for specified ranges of regional or national experiments. Search parameters were applied to define soil test calibrations. These included farming system (dryland or irrigated), year of experiment, soil type, crop type, soil test, depth of soil sampling and soil test units. Other data filters based on site metadata, such as method of nutrient placement, can be applied to enable more definitive calibrations. The calibrations are used to derive critical soil test values at 80, 90 and 95% relative crop yield with 95% confidence limits. However, the soil test criteria at 90% relative crop yield with 70% confidence limits have been chosen as the single calibration and reliability standard for all crops and soil tests. Corresponding yield increase (t/ha)-soil test relationships for an applied nutrient can also be accessed. The BFDC National Database and BFDC Interrogator can now be accessed online by trained, registered users. This paper describes the methodologies that underpinned the progressive development of this tool. Through the commitment of the grains and fertiliser industries, it is anticipated that the calibrations will be used to improve decision support systems used to generate fertiliser recommendations for Australian cropping industries. © CSIRO 2013.

Orchard P.W.,Graham Center for Agricultural Innovation | Hackney B.,Graham Center for Agricultural Innovation
Landscape Ecology | Year: 2016

Context: This short communication responds to calls for greater input from agronomists into landscape research as a means of contributing to managing the positive and negative effects of farming systems. This was recognised in New South Wales, Australia in relation to the management of soil acidity in landscapes of variable topography. Objective: The response was the development of a structured course (Landscan) aimed at educating land managers to match land use with landscape capability. The course characteristics are briefly presented in terms of reading, measuring and interpreting landscape features, understanding degradation processes, assessing available management tools and prioritising actions to balance production, profit and sustainability. Method: The main features of the course content and mode of delivery are detailed including evaluation of participants in regards to increased knowledge, skills and potential changes in practice. Results: Over 1000 land managers have completed the course with most indicating that they will alter priorities, change strategies and adjust goals as a result and 97 % indicated they would recommend the workshops to others. The Landscan framework also provides a means for researchers to incorporate their results for rapid uptake as well as identifying research gaps. The course has been used to deliver integrated group outcomes in areas of soil health, biodiversity, water quality and weed management. Conclusion: The framework addresses the issue of greater involvement of agronomists in landscape research and has successfully initiated dialogue with other disciplines. While the emphasis to date has been on livestock production in variable landscapes the model should be applicable in other farming systems. © 2015, Springer Science+Business Media Dordrecht.

Dowling C.W.,Back Paddock Company P L | Speirs S.D.,Graham Center for Agricultural Innovation
Crop and Pasture Science | Year: 2013

Scientists readily suggest that research and development is not complete until findings and conclusions are reported in the peer-reviewed literature. The authors suggest that industry-specific relevant research and development is actually not complete until the key outputs are extended to primary stakeholder groups. In the case of 'Making Better Fertiliser Decisions for Cropping Systems in Australia' (BFDC), this meant training key members of the grains and fertiliser industries, where nitrogen, phosphorus, potassium, and sulfur recommendations are derived from soil tests and provided to farmers. The BFDC project applied a two-part cascading approach to extension and training to reach the grains and fertiliser industries. The train-the-trainer program (Level 1) was undertaken and targeted at influential and experience persons such as technical leaders and those who influenced crop-nutrition decision support systems (DSS) within interested organisations. Level 2 activities targeted individuals within organisations who had direct discussion with farmers about soil testing, and their training was facilitated by a Level 1 trained colleague. Development of extension plans, training course structure, and training resources was conducted in parallel with the development of the BFDC National Database and BFDC Interrogator from the commencement of the project. In so doing, it was agreed that controlled access to the information should be established to maintain a consistent standard of use and to provide a platform for gathering feedback to guide future developments (e.g. of the BFDC Interrogator or prioritising future experimental investment). The BFDC extension approach targeted 100 individuals from the Level 1 audience and 30 individuals from the Level 2 audience through seven train-the-trainer level workshops conducted across Australia. As a result of reaching this audience, it was expected that the cumulative effect of the cascading extension strategy and input of BFDC Interrogator critical nutrient concentrations in commercial soil analysis interpretation software would indirectly and directly influence the crop nutrient management decisions of up to 5000 Australian grain farmers in the year after the commencement of training activities. Exit survey results, conducted as part of the BFDC train-the-trainer workshops, were aggregated across all Level 1 workshops. These survey results showed that the most significant benefit of the training was the usefulness of the BFDC Interrogator training manual and the additional teaching aids supplied. The importance and significance to the industry of the collation of data through BFDC was also highlighted as a benefit. Reflecting industry knowledge gaps (e.g. crop×nutrient×geographic region interactions), the lowest ranking survey results focused on the ability of the BFDC National Database to provide usable critical soil test criteria for several situations. Yet despite this reported shortcoming, participants recognised the significance of the structure, tools, skills, and knowledge gained through the training workshop and the importance of the established critical levels. While face-to-face training enables robust discussion, the 'time-poor' nature of roles for agricultural professionals appeared to limit the uptake of training opportunities. Therefore, training materials are being developed into an online course focused particularly on university requirements and the development of agricultural professionals. © CSIRO 2013.

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