Lime application reduces potassium and nitrate leaching on sandy soils

Kalium (K)-Auslaugung kommt in leicht strukturierten Böden häufig vor und reduziert die im Boden für die Pflanzen verfügbare Menge K. Diese Studie untersuchte die Auswirkung der Kalkanwendung und der K-Raten (null, 20, 60 kg K/ha) auf die K-Auslaugung und andere Sickerwasserparameter von vier sandigen Böden im Westen Australiens. Drei von vier Böden unterschieden sich in der K-Auslaugung nicht zwischen den Raten von Null und 20 kg K/ha, während 60 kg K/ha die K-Auslaugung in allen vier Böden erhöhten. Bei den Merredin-Böden verzögerte die Kalkanwendung die K-Auslaugung bei 60 kg K/ha deutlich und zeigte einen K-Auslaugungspeak bei 4,75 Porenvolumen (PV) im gekalkten Boden (pHCaCl2: 6,20), jedoch bei 3 PV im nicht gekalkten Boden (pHCaCl2: 4,50), und das Kalken reduzierte auch die Gesamt­menge an ausgelaugtem K und NO3. In ähnlicher Weise trat der Peak der K-Auslaugung bei 2–3 PV in den anderen beiden nicht gekalkten Böden auf. Die maximalen NO3-Konzentrationen von Sickerwasser bei 60 kg K/ha betrugen 46 mg/l bei 2 PV mit Kalk gegenüber 110 mg/l bei 1,25 PV ohne Kalk, während die Menge an ausgelaugtem NO3 aus Böden ohne K-Zugabe größer war als aus den mit K behandelten Böden. Die Ergebnisse legen nahe, dass die Kalkung eines sauren Sandes die K- und NO3-Auswaschung verlangsamen und verringern kann und erhebliche Auswirkungen auf das K-Dünger-Management auf solchen Böden hat.Potassium (K) leaching is common in light-textured soils and reduces soil available K to plants. This study examined the effect of lime application and K rates (nil, 20, 60 kg K/ha) on K leaching and other leachate parameters of four sandy soils in Western Australia. Three out of four soils did not differ in K leaching between the rates of nil and 20 kg K/ha, whereas 60 kg K/ha increased K leaching in all four soils. For the Merredin soils, lime applica­tion markedly delayed K leaching at 60 kg K/ha, showing K leaching peak at 4.75 pore volume (PV) in the limed soil (pHCaCl2: 6.20) but at 3 PV in the non-limed soil (pHCaCl2: 4.50), and liming also reduced total amount of leached K and NO3. Similarly, the peak of K leaching occurred at 2–3 PV in the other two non-limed soils. Maximum leachate NO3 concentrations at 60 kg K/ha were 46 mg/L at 2 PV with lime versus 110 mg/L at 1.25 PV without lime, while the amount of leached NO3 from nil K soils was greater than from the K treated soils. The results suggest that liming of an acid sand can slow down and reduce K and NO3 leaching and have significant implication for K-fertilizer management on such soils

Crop Updates 2006 - Oilseeds

This session covers thirteen papers from different authors: 1. INTRODUCTION, Graham Walton, CONVENOR, Department of Agriculture 2. The performance of new TT canola varieties in National Variety Testing (NVT) WA, Fiona Martin, Research Agronomist, Agritech Crop Research 3. Comparison of TT Canola Varieties in Oilseeds WA Trials – 2005, Collated by G.H. Walton, Department of Agriculture, WA, from a collaboration between Oilseeds WA, Seed Companies, Agronomists and Growers 4. An overview of the potential for a Biofuels Industry in Western Australia, Anne Wilkins and Nathan Hancock, Department of Agriculture 5. Retrieval of fertile progeny from interspecific crosses between Brassica napus and B. carinata using microspore culture, Matthew Nelson, Marie-Claire Castello, Linda Thomson, Anouska Cousin, Guijun Yan and Wallace Cowling; School of Plant Biology (M084), The University of Western Australia 6. Advances in canola blackleg epidemiology and its implication in understanding and managing the disease, Moin Salam, Bill MacLeod, Ravjit Khangura, Jean Galloway and Art Diggle, Department of Agriculture 7. Effect of fertiliser phosphorus and nitrogen on grain yields and concentration of oil and protein of canola grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 8. Effect of applying fertiliser potassium and nitrogen on canola grain yields and concentration of oil and protein in grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 9. Effect of fertiliser nitrogen and sulfer on canola yields and concentration of oil in grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 10. Uptake of K from topsoil and subsoil by canola, P.M. Damon and Z. Rengel, Faculty of Natural and Agricultural Sciences, The University of WA 11. Accumulation of P and K by canola plants, Terry Rose, Zed Rengel and Qifu Ma, Faculty of Natural and Agricultural Sciences, The University of WA 12. Varied response from applying nitrogen at late flowering in canola! Dave Eksteen, Agronomist, United Farmers Cooperative 13. To investigate the timing, rate and placement of nitrogen on canola – Jerdacuttup 2005, Dave Eksteen, Agronomist, United Farmers Cooperativ

Top scoring pairs for feature selection in machine learning and applications to cancer outcome prediction

<b>Background</b> The widely used k top scoring pair (k-TSP) algorithm is a simple yet powerful parameter-free classifier. It owes its success in many cancer microarray datasets to an effective feature selection algorithm that is based on relative expression ordering of gene pairs. However, its general robustness does not extend to some difficult datasets, such as those involving cancer outcome prediction, which may be due to the relatively simple voting scheme used by the classifier. We believe that the performance can be enhanced by separating its effective feature selection component and combining it with a powerful classifier such as the support vector machine (SVM). More generally the top scoring pairs generated by the k-TSP ranking algorithm can be used as a dimensionally reduced subspace for other machine learning classifiers.<p></p> <b>Results</b> We developed an approach integrating the k-TSP ranking algorithm (TSP) with other machine learning methods, allowing combination of the computationally efficient, multivariate feature ranking of k-TSP with multivariate classifiers such as SVM. We evaluated this hybrid scheme (k-TSP+SVM) in a range of simulated datasets with known data structures. As compared with other feature selection methods, such as a univariate method similar to Fisher's discriminant criterion (Fisher), or a recursive feature elimination embedded in SVM (RFE), TSP is increasingly more effective than the other two methods as the informative genes become progressively more correlated, which is demonstrated both in terms of the classification performance and the ability to recover true informative genes. We also applied this hybrid scheme to four cancer prognosis datasets, in which k-TSP+SVM outperforms k-TSP classifier in all datasets, and achieves either comparable or superior performance to that using SVM alone. In concurrence with what is observed in simulation, TSP appears to be a better feature selector than Fisher and RFE in some of the cancer datasets.<p></p> <b>Conclusions</b> The k-TSP ranking algorithm can be used as a computationally efficient, multivariate filter method for feature selection in machine learning. SVM in combination with k-TSP ranking algorithm outperforms k-TSP and SVM alone in simulated datasets and in some cancer prognosis datasets. Simulation studies suggest that as a feature selector, it is better tuned to certain data characteristics, i.e. correlations among informative genes, which is potentially interesting as an alternative feature ranking method in pathway analysis

Crop Updates 2011 - Nutrition, Precision Agriculture & Climate and Forecasting

This session covers sixteen papers from different authors: Nutrition 1. Balance® used in conventional cropping practice with half of the upfront fertiliser rate can sustain crop yield and build soil biological fertility, Deb Archdeacon1, Andrew Gulliver2 and David Cullen2, 1Agronomica, Wellington Mill, WA, 2Custom Composts, Nambeelup, WA 2. Effects of potassium (K) supply on plant growth, potassium uptake and grain Yield in wheat grown in grey sand, Qifu Ma1, Richard Bell1, Ross Brennan2 and Craig Scanlan2, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food 3. Improving fertiliser management: redefining the relationship between soil tests and crop responses for wheat in WA, Wen Chen1, 2, Ross Brennan2, Geoff Anderson2, Richard Bell1 and Mike Bolland2, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food 4. Improved phosphorus and potassium management: redefining the soil test and lupin response relationships in WA, Wen Chen1, 2, Ross Brennan2, Geoff Anderson2, Richard Bell1 and Mike Bolland2, 1School of Environmental Science, Murdoch University, Western Australia, 2Department of Agriculture and Food 5. Converting phosphorus retention index (PRI) to phosphorus buffering index (PBI) for Western Australian soils, Peter Rees and Sandy Alexander, Summit Fertilizers 6. Variability of radiometric potassium and Colwell potassium relationships across the Great Southern, Frank D’Emden, Precision Agronomics Australia 7. Rotary spading and mouldboard ploughing of water-repellent sandplain soils fulfils promise, Stephen Davies, Craig Scanlan and Breanne Best, Department of Agriculture and Food 8. Soil nitrous oxide (N2O) fluxes are low from a grain legume crop grown in a semi-arid climate Louise Barton1, Klaus Butterbach-Bahl2, Ralph Kiese2 and Daniel Murphy1, 1 School of Earth & Environment, University of Western Australia, 2 Karlsruhe Institute of Technology, Institute for Meteorology & Climate Research, Garmisch-Partenkirchen, Germany, 9. Mouldboard ploughing of sandplain soils – more grain, fewer weeds, Peter Newman Department of Agriculture and Food Precision Agriculture 10.What’s preventing growers from implementing precision agriculture (PA)? Roger Mandel1, Roger Lawes2 and Michael Robertson2, 1Curtin University, 2CSIRO 11. On how many paddocks does precision agriculture (PA) deliver a return? Roger Lawes1, Michael Robertson1 and Roger Mandel2, 1CSIRO Ecosystem Sciences, Floreat, WA, 2Curtin University 12. Demonstration pf precision agriculture (PA) principles in the Great Southern, Western Australia, Derk Bakker1, Jeremy Lemon1, Alison Lacey1, John Paul Collins1, Roger Mandel2, Frank D’Emden3, Glen Riethmuller1, 1Department of Agriculture and Food, 2Curtin University, 3Precision Agronomics Australia Climate and Forecasting 13. Statistical seasonal rainfall forecasts for south west Australia, Fiona H Evans Department of Agriculture of Food 14. How has changing climate recently affected Western Australia’s capacity to increase crop productivity and water use efficiency? David Stephens, Department of Agriculture and Food 15. Is Yield Prophet® a useful tool in Western Australia? — an agribusiness perspective, Caroline Peek, Department of Agriculture and Food 16. A season of Yield Prophet® — how it saw the dry, Tim Scanlon and Caroline Peek Department of Agriculture of Foo

Indole Alleviates Diet-induced Hepatic Steatosis and Inflammation in a Manner Involving Myeloid Cell PFKFB3

Background and aims: Indole is a microbiota metabolite that exerts anti-inflammatory responses. However, the relevance of indole to human non-alcoholic fatty liver disease (NAFLD) is not clear. It also remains largely unknown whether and how indole acts to protect against NAFLD. The present study sought to examine the association between the circulating levels of indole and liver fat content in human subjects and explore the mechanisms underlying indole actions in mice with diet-induced NAFLD. Approach and results: In a cohort of 137 subjects, the circulating levels of indole were reversely correlated with body mass index. In addition, the circulating levels of indole in obese subjects were significantly lower than those in lean subjects and were accompanied with increased liver fat content. At the whole-animal level, treatment of high-fat diet (HFD)-fed C57BL/6J mice with indole caused significant decreases in the severity of hepatic steatosis and inflammation. In cultured cells, indole treatment stimulated the expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a master regulatory gene of glycolysis, and suppressed macrophage proinflammatory activation in a PFKFB3-dependent manner. Moreover, myeloid cell-specific PFKFB3 disruption exacerbated the severity of HFD-induced hepatic steatosis and inflammation and blunted the effect of indole on alleviating diet-induced NAFLD phenotype. Conclusions: Taken together, our results demonstrate that indole is relevant to human NAFLD and capable of alleviating diet-induced NAFLD phenotypes in mice in a myeloid cell PFKFB3-dependent manner. Therefore, indole mimetic and/or macrophage-specific PFKFB3 activation may be the viable preventive and/or therapeutic approaches for inflammation-associated diseases including NAFLD

Crop Updates 2007 - Lupins, Pulses and Oilseeds

This session covers forty eight papers from different authors: 2006 REGIONAL ROUNDUP 1. South east agricultural region, Mark Seymour1 and Jacinta Falconer2, 1Department of Agriculture and Food, 2Cooperative Bulk Handling Group 2. Central agricultural region, Ian Pritchard, Department of Agriculture and Food 3. Great Southern and Lakes region, Rodger Beermier, Department of Agriculture and Food 4. Northern agricultural region, Wayne Parker and Martin Harries, Department of Agriculture and Food LUPINS 5. Development of anthracnose resistant and early flowering albus lupins (Lupinus albus L) in Western Australia, Kedar Adhikari and Geoff Thomas, Department of Agriculture and Food 6. New lupins adapted to the south coast, Peter White, Bevan Buirchell and Mike Baker, Department of Agriculture and Food 7. Lupin species and row spacing interactions by environment, Martin Harries, Peter White, Bob French, Jo Walker, Mike Baker and Laurie Maiolo, Department of Agriculture and Food 8. The interaction of lupin species row spacing and soil type, Martin Harries, Bob French, Laurie Maiolo and Jo Walker, Department of Agriculture and Food 9. The effects of row spacing and crop density on competitiveness of lupins with wild radish, Bob French and Laurie Maiolo, Department of Agriculture and Food 10. The effect of time of sowing and radish weed density on lupin yield, Martin Harries and Jo Walker, Department of Agriculture and Food 11. Interaction of time of sowing and weed management in lupins, Martin Harries and Jo Walker, Department of Agriculture and Food 12. Delayed sowing as a strategy to manage annual ryegrass, Bob French and Laurie Maiolo, Department of Agriculture and Food 13. Is delayed sowing a good strategy for weed management in lupins? Bob French, Department of Agriculture and Food 14. Lupins aren’t lupins when it comes to simazine, Peter White and Leigh Smith, Department of Agriculture and Food 15. Seed yield and anthracnose resistance of Tanjil mutants tolerant to metribuzin, Ping Si1, Bevan Buirchell1,2 and Mark Sweetingham1,2, 1Centre for Legumes in Mediterranean Agriculture, Australia; 2Department of Agriculture and Food 16. The effect of herbicides on nodulation in lupins, Lorne Mills1, Harmohinder Dhammu2 and Beng Tan1, 1Curtin University of Technology and 2Department of Agriculture and Food 17. Effect of fertiliser placements and watering regimes on lupin growth and seed yield in the central grain belt of Western Australia, Qifu Ma1, Zed Rengel1, Bill Bowden2, Ross Brennan2, Reg Lunt2 and Tim Hilder2, 1Soil Science & Plant Nutrition UWA, 2Department of Agriculture and Food 18. Development of a forecasting model for Bean Yellow Mosaic Virus in lupins, T. Maling1,2, A. Diggle1, D. Thackray1,2, R.A.C. Jones2, and K.H.M. Siddique1, 1Centre for Legumes in Mediterranean Agriculture, The University of Western Australia; 2Department of Agriculture and Food 19. Manufacturing of lupin tempe,Vijay Jayasena1,4, Leonardus Kardono2,4, Ken Quail3,4 and Ranil Coorey1,4, 1Curtin University of Technology, Perth, Australia, 2Indonesian Institute of Sciences (LIPI), Indonesia, 3BRI Australia Ltd, Sydney, Australia, 4Grain Foods CRC, Sydney, Australia 20. The impact of lupin based ingredients in ice-cream, Hannah Williams, Lee Sheer Yap and Vijay Jayasena, Curtin University of Technology, Perth WA 21. The acceptability of muffins substituted with varying concentrations of lupin flour, Anthony James, Don Elani Jayawardena and Vijay Jayasena, Curtin University of Technology, PerthWA PULSES 22. Chickpea variety evaluation, Kerry Regan1, Rod Hunter1, Tanveer Khan1,2and Jenny Garlinge1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 23. Advanced breeding trials of desi chickpea, Khan, T.N.1, Siddique, K.H.M.3, Clarke, H.2, Turner, N.C.2, MacLeod, W.1, Morgan, S.1, and Harris, A.1, 1Department of Agriculture and Food, 2Centre for Legumes in Mediterranean Agriculture, 3TheUniversity of Western Australia 24. Ascochyta resistance in chickpea lines in Crop Variety Testing (CVT) of 2006, Tanveer Khan1 2, Bill MacLeod1, Alan Harris1, Stuart Morgan1and Kerry Regan1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 25. Yield evaluation of ascochyta blight resistant Kabuli chickpeas, Kerry Regan1and Kadambot Siddique2, 1Department of Agriculture and Food, 2Institute of Agriculture, The University of Western Australia 26. Pulse WA Chickpea Industry Survey 2006, Mark Seymour1, Ian Pritchard1, Wayne Parker1and Alan Meldrum2, 1Department of Agriculture and Food, 2Pulse Australia 27. Genes from the wild as a valuable genetic resource for chickpea improvement, Heather Clarke1, Helen Bowers1and Kadambot Siddique2, 1Centre for Legumes in Mediterranean Agriculture, 2Institute of Agriculture, The University of Western Australia 28. International screening of chickpea for resistance to Botrytis grey mould, B. MacLeod1, Dr T. Khan1, Prof. K.H.M. Siddique2and Dr A. Bakr3, 1Department of Agriculture and Food, 2The University of Western Australia, 3Bangladesh Agricultural Research Institute 29. Balance® in chickpea is safest applied post sowing to a level seed bed, Wayne Parker, Department of Agriculture and Food, 30. Demonstrations of Genesis 510 chickpea, Wayne Parker, Department of Agriculture and Food 31. Field pea 2006, Ian Pritchard, Department of Agriculture and Food 32. Field pea variety evaluation, Kerry Regan1, Rod Hunter1, Tanveer Khan1,2 and Jenny Garlinge1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 33. Breeding highlights of the Australian Field Pea Improvement Program (AFPIP),Kerry Regan1, Tanveer Khan1,2, Phillip Chambers1, Chris Veitch1, Stuart Morgan1 , Alan Harris1and Tony Leonforte3, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia, 3Department of Primary Industries, Victoria 34. Field pea germplasm enhancement for black spot resistance, Tanveer Khan, Kerry Regan, Stuart Morgan, Alan Harris and Phillip Chambers, Department of Agriculture and Food 35. Validation of Blackspot spore release model and testing moderately resistant field pea line, Mark Seymour, Ian Pritchard, Rodger Beermier, Pam Burgess and Leanne Young, Department of Agriculture and Food 36. Yield losses from sowing field pea seed infected with Pea Seed-borne Mosaic Virus, Brenda Coutts, Donna O’Keefe, Rhonda Pearce, Monica Kehoe and Roger Jones, Department of Agriculture and Food 37. Faba bean in 2006, Mark Seymour, Department of Agriculture and Food 38. Germplasm evaluation – faba bean, Mark Seymour1, Terri Jasper1, Ian Pritchard1, Mike Baker1 and Tim Pope1,2, 1Department of Agriculture and Food, , 2CLIMA, The University of Western Australia 39. Breeding highlights of the Coordinated Improvement Program for Australian Lentils (CIPAL), Kerry Regan1, Chris Veitch1, Phillip Chambers1 and Michael Materne2, 1Department of Agriculture and Food, 2Department of Primary Industries, Victoria 40. Screening pulse lentil germplasm for tolerance to alternate herbicides, Ping Si1, Mike Walsh2 and Mark Sweetingham1,3, 1Centre for Legumes in Mediterranean Agriculture, 2West Australian Herbicide Resistance Initiative, 3Department of Agriculture and Food 41. Genomic synteny in legumes: Application to crop breeding, Phan, H.T.T.1, Ellwood, S.R.1, Hane, J.1, Williams, A.1, Ford, R.2, Thomas, S.3 and Oliver R1, 1Australian Centre of Necrotrophic Plant Pathogens, Murdoch University, 2BioMarka, University of Melbourne, 3NSW Department of Primary Industries 42. Tolerance of lupins, chickpeas and canola to Balanceâ(Isoxaflutole) and Galleryâ (Isoxaben), Leigh Smith and Peter White, Department of Agriculture and Food CANOLA AND OILSEEDS 43. The performance of TT Canola varieties in the National Variety Test (NVT),WA,2006,Katie Robinson, Research Agronomist, Agritech Crop Research 44. Evaluation of Brassica crops for biodiesel in Western Australia, Mohammad Amjad, Graham Walton, Pat Fels and Andy Sutherland, Department of Agriculture and Food 45. Production risk of canola in different rainfall zones in Western Australia, Imma Farré1, Michael Robertson2 and Senthold Asseng3, 1Department of Agriculture and Food, 2CSIRO Sustainable Ecosystems, 3CSIRO Plant Industry 46. Future directions of blackleg management – dynamics of blackleg susceptibility in canola varieties, Ravjit Khangura, Moin Salam and Bill MacLeod, Department of Agriculture and Food 47. Appendix 1: Contributors 48. Appendix 2: List of common acronym

Crop Updates 2008 - Farming Systems

This session covers thirty nine papers from different authors: PLENARY 1. Developments in grain end use, Dr John de Majnik, New Grain Products, GRDC, Mr Paul Meibusch, New Farm Products and Services, GRDC, Mr Vince Logan, New Products Executive Manager, GRDC PRESENTATIONS 2. Global warming potential of wheat production in Western Australia: A life cycle assessment, Louise Barton1, Wahid Biswas2 and Daniel Carter3, 1School of Earth & Geographical Sciences, The University of Western Australia, 2Centre of Excellence in Cleaner Production, Division of Science and Engineering, Curtin University of Technology, 3Department of Agriculture and Food 3. How much fuel does your farm use for different farm operations? Nicolyn Short1, Jodie Bowling1, Glen Riethmuller1, James Fisher2 and Moin Salam1, 1Department of Agriculture and Food, 2Muresk Institute, Curtin University of Technology 4. Poor soil water storage and soil constraints are common in WA cropping soils, Stephen Davies, Jim Dixon, Dennis Van Gool and Alison Slade, Department of Agriculture and Food, Bob Gilkes, School of Earth and Geographical Sciences, University of Western Australia 5. Developing potential adaptations to climate change for low rainfall farming system using economic analysis tool. STEP, Megan Abrahams, Caroline Peek, Dennis Van Gool, Daniel Gardiner and Kari-Lee Falconer, Department of Agriculture and Food 6. What soil limitations affect the profitability of claying on non-wetting sandplain soils? David Hall1, Jeremy Lemon1, Harvey Jones1, Yvette Oliver2 and Tania Butler1, 1Department of Agriculture and Food, 2CSIRO Div Sustainable Ecology, Perth 7. Farming systems adapting to a variable climate; Two case studies, Kari-Lee Falconer, Department of Agriculture and Food 8. Importance of accounting for variation in crop yield potential when making fertiliser decisions, Michael Robertson and Yvette Oliver, CSIRO Sustainable Ecosystems, Floreat 9. Soil acidity is a widespread problem across the Avon River Basin, Stephen Carr1, Chris Gazey2, David York1 and Joel Andrew1, 1Precision SoilTech, 2Department of Agriculture and Food 10. The use of soil testing kits and ion-selective electrodes for the analysis of plant available nutrients in Western Australian soils, Michael Simeoni and Bob Gilkes School of Earth and Geographical Sciences, University of Western Australia 11. Redlegged earth mite resistance and integrated strategies for their control in Western Australia, Mangano G. Peter and Micic Svetlana, Department of Agriculture and Food 12. The economics of treating soil pH (liming), Chris Gazey, Steve Davies, Dave Gartner and Adam Clune, Department of Agriculture and Food, 13. Health benefits – A future differentiator for high value grains, Matthew Morell, Theme Leader, CSIRO Food Futures Flagship 14. Carbon in Sustralian cropping soils – We need to be realistic, Alan Umbers (M Rur Sc), GRDC/DAFF Sustainable Industries Initiative Project 15. AGWEST® Bartolo bladder clover (Trifolium spumosum) − a low cost annual pasture legume for the wheat/sheep zone, Angelo Loi, Brad Nutt and Clinton Revell, Department of Agriculture and Food 16. Maximising the value of point based soil sampling: Monitering trends in soil pH through time, Joel Andrew1, David York1, Stephen Carr1 and Chris Gazey2, 1Precision SoilTech, 2Department of Agriculture and Food 17. Improved crop root growth and productivity with deep ripping and deep placed lime, Stephen Davies1, Geoff Kew2*, Chris Gazey1, David Gartner1 and Adam Clune1, 1Department of Agriculture and Food, 2School of Earth and Geographical Sciences University of Western Australia, *Presenting author 18. The role of pastures in hosting Root Lesion Nematode (RLN, Pratylenchus neglectus), Vivien Vanstone, Ali Bhatti and Ming Pei You, Department of Agriculture and Food 19. To rip or not to rip. When does it pay? Imma Farre, Bill Bowden and Stephen Davies, Department of Agriculture and Food 20. Can yield be predicted from remotely sensed data, Henry Smolinski, Jane Speijers and John Bruce, Department of Agriculture and Food 21. Rotations for profit, David McCarthy and Gary Lang, Facey Group, Wickepin, WA 22. Rewriting rules for the new cropping economics, David Rees, Consultant, Albany 23. Reducing business risk in Binnu! – A case study, Rob Grima, Department of Agriculture and Food 24. Does improved ewe management offer grain farmers much extra profit? John Young, Farming Systems Analysis Service, Ross Kingwell, Department of Agriculture and Food, and UWA, Chris Oldham, Department of Agriculture and Food RESEARCH HIGHLIGHTS 25. Crop establishment and productivity with improved root zone drainage, Dr Derk Bakker, Research Officer, Department of Agriculture and Food 26. Will wheat production in Western Australia be more risky in the future? Imma Farre and Ian Foster, Department of Agriculture and Food PAPERS 27. Building farmers’ adaptive capacity to manage seasonal variability and climate change, David Beard, Department of Agriculture and Food 28. Precision placement increases crop phosphorus uptake under variable rainfall: Simulation studies, Wen Chen1 2, Richard Bell1, Bill Bowden2, Ross Brennan2, Art Diggle2 and Reg Lunt2, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food 29. What is the role of grain legumes on red soil farms? Rob Grima, Department of Agriculture and Food 30. Fertiliser placement influences plant growth and seed yield of grain crops at different locations of WA, Qifu Ma1, Zed Rengel1, Bill Bowden2, Ross Brennan2, Reg Lunt2 and Tim Hilder2, 1Soil Science & Plant Nutrition, University of Western Australia, 2Department of Agriculture and Food 31. A review of pest and disease occurrences for 2007, Peter Mangano and Dusty Severtson, Department of Agriculture and Food 32. Effect of stocking rates on grain yield and quality of wheat in Western Australia in 2007, Shahajahan Miyan, Sam Clune, Barb Sage and Tenielle Martin, Department of Agriculture and Food 33. Storing grain is not ‘set and forget’ management, Chris Newman, Department of Agriculture and Food 34. Improving understanding of soil plant available water capacity (PAWC): The WA soil water database (APSoil), Yvette Oliver, Neal Dalgliesh and Michael Robertson, CSIRO Sustainable Ecosystems 35. The impact of management decisions in drought on a low rainfall northern wheatbelt farm, Caroline Peek and Andrew Blake, Department of Agriculture and Food 37. Cullen – A native pasture legume shows promise for the low-medium rainfall cropping zone, Megan Ryan, Richard Bennett, Tim Colmer, Daniel Real, Jiayin Pang, Lori Kroiss, Dion Nicol and Tammy Edmonds-Tibbett, School of Plant Biology, The University of Western Australia and Future Farm Industries CRC 38. Climate risk management tools – useful, or just another gadget? Lisa Sherriff, Kari-Lee Falconer, Daniel Gardiner and Ron McTaggart Department of Agriculture and Food 39. Benefits of crop rotation for management of Root Lesion Nematode (RLN, Pratylenchus neglectus), Vivien Vanstone, Sean Kelly and Helen Hunter, Department of Agriculture and Foo

Soil salinity and water stress modify crop sensitivity to SO2 exposure

Sulphur dioxide (SO2) is a pnmary gaseous pollutant which has toxic effects on the growth, yield and quality of both agricultural and natural plant species. Although plant responses to SO2 exposure have been extensively studied, much less is understood concerning the influences of other environmental stresses on the expression of effects of gaseous air pollutants. Evaluation of such interactions should be of an economic importance in agriculture and horticulture since plants growing in the field usually encounter air pollution and other stresses simultaneously. Soil water stress and salinity are the common environmental stresses and they have some physiological similarities. This thesis aims to investigate to what extent water stress and salinity modify or amplify the detrimental effects of SO2 on foliar injury, plant growth and yield, and some physiological and biochemical changes in potato (Solanum tuberosum L. cv. Russet Burbank) and soybean (Glycine max L. cv. Buchanan) crops under field conditions. SO2 exposure induced growth reductions in well-watered potato plants but usually not in the water-stressed plants, indicating a protective function of soil moisture stress in the response of plants to SO2. This could be caused by a reduced SO2 uptake m water-stressed plants, as well-watered plants had much higher leaf sulphur concentrations than did the water-stressed plants at the same SO2 fumigation levels. SO2 also increased leaf sulphur concentrations in soybean, but simultaneous exposure to SO2 and salinity significantly decreased leaf sulphur concentrations when compared with exposure to SO2 alone. As a consequence, SO2-induced foliar injury was more severe in the well-watered or nonsaline plants than in the water-stressed or saline plants. Exposure conditions can also be important in determining the response of a plant to stress interactions. Contrasts of sequential and simultaneous exposures to SO2 and salinity were made in this project so as to examine stress compensatory mechanisms and predisposition characteristics. It was found that low salinity pretreatment (27 mM NaCl) ameliorated the detrimental effects of SO2 on soybean growth probably by inducing stomatal closure. However, high salinity (48 mM NaCl) treated plants, which also showed high stomatal resistance, were severely injured by subsequent SO2 exposure especially at high SO2 concentrations (300 nl 1-1). It was likely that high salinity pretreatment decreased or even destroyed plant homeostasis due to direct injury of high ion concentrations. By comparison, plants pretreated with SO2 became vulnerable to salt injury and those pretreated with high SO2 were killed after 12 days of high salt stress. This was probably because SO2 altered the patterns of assimilate allocation favouring shoot growth at the expense of root growth and induced other metabolic changes. As a consequence, the resistance of polluted plants to salinity stress was reduced. SO2 pollutant increased the shoot to root ratios by either reducing root growth or stimulating shoot growth, whereas soil moisture stress had the opposite effect. Exposure to 300 nl 1-1 SO2 under well-watered conditions induced an increase in the shoot to root (including tuber) ratios of potato plants early in the growing season. In contrast, water stress decreased the ratios in the control and 110 nl 1-1 SO2 treatments, but not at 300 nl I-1 SO2 indicating that high SO2 had disrupted this acclimatory response to soil moisture stress. SO2-induced increase in the shoot to root ratios was also observed in the soybean experiments. However, it appeared that soil salinity did not significantly affect the ratios. High SO2 decreased the number and weight of root nodules, and suppressed nodule nitrogenase activity. Consequently, both shoot and root nitrogen concentrations were reduced. In combination with low salinity, however, the adverse effects of high SO2 on nodule number, specific nodule activity and plant nitrogen concentrations were ameliorated. Biomass was usually not very sensitive to the interactive effects of SO2 and salinity, probably because it is slower to respond to the stresses following physiological and biochemical processes. In the field, stress interactions may become even more complicated due to interactions with other environmental stresses. In conclusion, moderate soil salinity and moisture stress can modify crop sensitivity to SO2 exposure mainly through stomatal mechanisms. Such interactions, together with the knowledge of interactions of gaseous au pollutants and other environmental stresses (e.g. light, humidity and temperature), are important when we attempt to establish dose or concentration-response relationships for the development of predictive models for the effects of air pollutants on crops or native plants. Environmental factors may readjust the dose thresholds of au pollutants, above which detrimental effect are likely and below which insignificant effects or growth stimulations occur. Therefore, air quality standards designed to protect vegetation may need to· consider variations in regional environmental conditions

The Forms and Sources of Cytokinins in Developing White Lupine Seeds and Fruits

A comprehensive range of cytokinins (CK) was identified and quantified by gas chromatography-mass spectrometry in tissues of and in xylem and phloem serving developing white lupine (Lupinus albus) fruits. Analyses were initiated at anthesis and included stages of podset, embryogenesis, and seed filling up to physiological maturation 77 d post anthesis (DPA). In the first 10 DPA, fertilized ovaries destined to set pods accumulated CK. The proportion of cis-CK:trans-CK isomers was initially 10:1 but declined to less than 1:1. In ovaries destined to abort, the ratio of cis-isomers to trans-isomers remained high. During early podset, accumulation of CK (30–40 pmol ovary(−1)) was accounted for by xylem and phloem translocation, both containing more than 90% cis-isomers. During embryogenesis and early seed filling (40–46 DPA), translocation accounted for 1% to 14% of the increases of CK in endosperm (20 nmol fruit(−1)) and seed coat (15 nmol fruit(−1)), indicating synthesis in situ. High CK concentrations in seeds (0.6 μmol g(−1) fresh weight) were transient, declining rapidly to less than 1% of maximum levels by physiological maturity. These data pose new questions about the localization and timing of CK synthesis, the significance of translocation, and the role(s) of CK forms in reproductive development

The Stability Analysis of a Multi-Port Single-Phase Solid-State Transformer in the Electromagnetic Timescale

This paper proposes an overall practical stability assessment for a multi-port single-phase solid-state transformer (MS3T) in the electromagnetic timescale. When multiple stable subsystems are combined into one MS3T, the newly formed MS3T has a certain possibility to be unstable. Thus, this paper discusses the stability assessment of the MS3T in detail. First and foremost, the structure of the MS3T and its three stage control strategies are proposed. Furthermore, the stability analysis of each of the MS3T’s subsystems is achieved through the closed loop transfer function of each subsystem, respectively, including an AC-DC front-end side converter, dual active bridge (DAB) with a high-frequency (HF) or medium-frequency (MF) transformer, and back-end side incorporating DC-AC and dc-dc converters. Furthermore, the practical impedance stability criterion in the electromagnetic timescale, which only requires two current sensors and one external high-bandwidth small-signal sinusoidal perturbation current source, is proposed by the Gershgorin theorem and Kirchhoff laws. Finally, the overall stability assessment, based on a modified impedance criterion for the MS3T is investigated. The overall practical stability assessment of the MS3T can be validated through extensive simulation and hardware results