Effect of Carbohydrate Source, Auxin and Endogenous Ethylene Upon Root Induction of Eucalyptus marginata donn EX SM. In Vitro

The utilisation of eucalypts around the world is increasing, mainly through the development of plantations. Clonal propagation has become important in some countries for production of such plantation trees. Micropropagation has been utilised to produce clones of trees selected for specific characteristics such as disease resistance, salt tolerance and fast growth rates. However, a suitable micropropagation protocol for all eucalypts has not been produced. One component of the micropropagation protocol, in which there is considerable difficulty, is the induction of adventitious roots on micropropagated shoots. Of particular interest, is the development of these procedures for Eucalyptus marginata (Jarrah) that have been selected for dieback (Phytophthora cinnamomi. Rands.) resistance. The effect of different sugar sources was examined on the rooting of jarrah shoots. Sucrose, glucose and fructose were all effective in promoting roots on jarrah in vitro. The effectiveness of each sugar varied between clones. In particular, three clones produced higher rooting on a medium containing fructose. For two of these clones the increase was as high as 30%. Interactions between auxin, sugar and ethylene were examined. Optimum root induction was obtained when approximately 10µM of auxin (indole butyric acid) and 2% sugar (sucrose or fructose) was used in the medium. As auxin and sugar concentration in the medium increased, the amount of ethylene produced also increased. Similarly, this increase in auxin, sugar and ethylene reduced the chlorophyll content of the shoots. The use of fructose appeared to produce lower amounts of ethylene than sucrose when used at the same concentration. The ethylene produced seemed to have no effect on the rooting response. The increases in rooting provided in some clones may be applicable to other clones that are difficult to root. This may lead to more efficient micropropagation with more clones being able to be produced in large numbers. This will increase the genetic diversity of clones that is currently available for jarrah breeding programs

Agricultural greenhouse gas emissions

Agriculture contributes 15.5 per cent of Australia’s emissions (Figure 1), largely due to methane, from ruminant livestock digestion, nitrous oxide from soils and carbon dioxide from fossil fuel use (Australian National Greenhouse Accounts 2011; ABARES 2011). This bulletin identifies current ways to reduce greenhouse gas emissions from Australian agriculture.https://researchlibrary.agric.wa.gov.au/bulletins/1176/thumbnail.jp

Changing climate, changing business practices : lessons from innovative growers

Climate change and increasing seasonal variability are challenging the production efforts of growers in lower rainfall environments of the Western Australian grain belt. Significantly less rainfall than the long-term average has fallen across southwest Western Australia during the past 30 years. Seasonal rainfall has also become more variable with later starts to the growing season and a general shift to more summer and less winter rainfall. Day and night-time temperatures, particularly in winter and autumn, have gradually increased, while in some areas, the risk of frost in spring has increased.https://researchlibrary.agric.wa.gov.au/bulletins/1083/thumbnail.jp

Relative effects of mammal herbivory and plant spacing on seedling recruitment following fire and mining

<p>Abstract</p> <p>Background</p> <p>There is much debate concerning which ecological constraints are the most limiting factors to seedling recruitment in disturbed communities. We provide the first comparison between selective herbivory and plant competition effects among two post-mined forest ecosystems (primary succession) and one post-fire woodland ecosystem (secondary succession). Animal exclosure assessments of nine common species across eight sites were performed for comparison within three locations separated by up to 200 km. Additionally, we asked whether pre-browsed plants differed in nutrient content between or within species in the separate systems.</p> <p>Results</p> <p>Among the nine common species, seven of these were affected by mammal herbivory while five shared a similar vulnerability to predation regardless of system. One species was limited by competition (planting density). There was a strong linear correlation between herbivore selectivity (% browsed) and impact (biomass loss) on the fertilized minesites, but not post-fire sites. Phosphorus and potassium were higher for most species in the post-mined system. Principal components analyses revealed that nutrients in shortest supply may be the most likely components of selection within each system. Among all locations, species with highest levels of phosphorus, ADF and leaf water content were often favoured, while high tannins and nitrogen content were generally selected against.</p> <p>Conclusion</p> <p>Herbivory, rather than seedling competition, was the limiting factor for plant performance among post-fire and post-mined reclamation areas. The post-fire seedlings were smaller and more water and nutrient limited, nevertheless browsing prevalence was equivalent at all locations with nearly all seedlings predated. Kangaroo density in the post-fire community declined from the beginning of the experiment, while numbers in the post-mined revegetation increased fourfold within one year. Differences in water and nutrient availability may explain why herbivores are more likely to be attracted to post-mined communities.</p

Last glacial benthic foraminiferal d18O anomalies in the polar North Atlantic: A modern analogue evaluation

Modern processes are evaluated to understand the possible mechanisms behind last glacial benthic foraminiferal δ18O anomalies that occurred concurrent with meltwater events in the polar North Atlantic; such anomalies in the Nordic seas were recently interpreted to be caused by brine formation. Despite intensive sea-ice production on circumarctic shelves, modern data show that brines ejected from sea-ice formation containing low δ18O water do not significantly contribute to deep waters in the Arctic Ocean today. Assuming that this process was, nevertheless, responsible for δ18O anomalies in Nordic seas deep water during the last glaciation, a broad, shallow shelf area adjacent to the Nordic seas, such as the Barents Sea, had to be seasonally free of sea-ice in order to serve as an area for brine formation. Another process which may explain δ18O-depleted water at depth is found in the Weddell Sea today, where a low δ18O signal in deep waters originates from ice shelf interactions. If temperature were considered the main mechanism for the low benthic δ18O values, an increase of 4°C must have occurred in the deep water. An analogous situation with a reversed water temperature pattern due to a subsurface inflow of warm Atlantic water is found today in the eastern Arctic Ocean, and deep water warming is observed in the Greenland Gyre in the absence of deep convection. Because paleoproxy data also indicate an Atlantic water inflow into the Nordic seas during such benthic δ18O anomalies, temperature as a principal mechanism of changing δ18O cannot be excluded

Crop Updates 2006 - Katanning

This session covers sixteen papers from different authors 2006 SEASONAL OUTLOOK, David Stephens and Michael Meuleners, Department of Agriculture Review of climate model summaries reported in the Department of Agriculture’s growing season outlooks, Meredith Fairbanks, Department of Agriculture Farmers commodity outlook 2006, Thomas Schulz, Department of Agriculture Why is salinity such a difficult problem for plant breeders? T J Flowers, TD Colmer, University of Western Australia Matching nitrogen supply to wheat demand in 2005, Narelle Simpson, Ron McTaggart, Wal Anderson, Lionel Martin and Dave Allen, Department of Agriculture Wheat varieties in 2006, Brenda Shackley, Department of Agriculture Performance of dwarf potential milling oat varieties in Western Australian environments, Raj Malik and Kellie Winfield, Department of Agriculture Field pea lessons for 2006, Rodger Beermir, Department of Agriculture Better returns from Durum wheat, Shahahan Miyan, Department of Agriculture Summer weeds can reduce grain yield and protein, Dr. Abul Hashem, Department of Agriculture, Dr Shahab Pathan, Department of Agriculture, Vikki Osten, Queensland Department of Primary Industries and Fisheries Management of Summer Weeds, Alex Douglas, Department of Agriculture Frost or Friction, Garren Knell, Steve Curtin, Wade Longmuir, Consult Ag Pty Ltd PROFITING FROM MARGINAL LAND SEMINAR Producing Bio-Diesel and rubber from marginal land?? Dr Henry Brockman, Department of Agriculture SGSL Producer network – on ground implementation of saltbush based pastures, Justin Hardy, Arjen Ryder, John Paul Collins and Jessica Johns, Department of Agriculture Enhancing the profitability of “Edenia” using saltbush and perenials, SGSL Producer case study, John Pepall, Jinka’s Hill LCDC Investment in saltland pastures, Allan Herbert, Department of Agricultur

Crop updates 2006 - Farming Systems

This session covers nineteen papers from different authors: SOIL AND NUTRIENT MANAGEMENT 1. Inve$tigating fertili$er inve$tment, Wayne Pluske, Nutrient Management Systems 2. KASM, the potassium in Agricultural System Model,Bill Bowden and Craig Scanlan, DAWA Northam and UWA, School of Earth and Geographical Sciences 3. Long term productivity and economic benefits of subsurface acidity management from surface and subsurface liming, Stephen Davies, Chris Gazey and Peter Tozer, Department of Agriculture 4. Furrow and ridges to prevent waterlogging, Dr Derk Bakker, Department of Agriculture 5. Nitrous oxide emissions from a cropped soil in Western Australia, Louise Barton1, David Gatter2, Renee Buck1, Daniel Murphy1, Christoph Hinz1and Bill Porter2 1School of Earth and Geographical Sciences, The University of Western Australia, 2Department of Agriculture GROWER DECISIONS 6. Managing the unmanageable, Bill Bowden Department of Agriculture 7. Review of climate model summaries reported in Department of Agriculture’s Season Outlook, Meredith Fairbanks, Department of Agriculture 8. Mapping the frost risk in Western Australia, Nicolyn Short and Ian Foster, Department of Agriculture 9. .35 kg/ha.day and other myths, James Fisher, Doug Abrecht and Mario D’Antuono, Department of Agriculture 10. Gaining with growers – Lessons from a successful alliance of WA Grower Groups, Tracey M. Gianatti, Grower Group Alliance 11. WA Agribusiness Trial Network Roundup – 2005, Paul Carmody, Local Farmer Group Network, UWA 12. Drivers of no-till adoption, Frank D’Emdenabc, Rick Llewellynabdand Michael Burtonb,aCRC Australian Weed Management; bSchool of Agricultural and Resource Economics, UWA. cDepartment of Agriculture, dCSIRO Sustainable Ecosystems, Adelaide PRODUCTION SYSTEMS, PRECISION AGRICULTURE AND SUSTAINABILITY 13. Maintaining wheat and lupin yields using phase pastures and shielded sprayers to manage increasing herbicide resistance, Caroline Peek, Nadine Eva, Chris Carter and Megan Abrahams, Department of Agriculture 14. Analaysis of a wheat-pasture rotation in the 330mm annual rainfall zone using the STEP model, Andrew Blake and Caroline Peek, Department of Agriculture 15. Response to winter drought by wheat on shallow soil with low seeding rate and wide row spacing, Paul Blackwell1, Sylvain Pottier2and Bill Bowden1 1 Department of Agriculture; 2Esitpa (France) 16. How much yield variation do you need to justify zoning inputs? Michael Robertson and Greg Lyle, CSIRO Floreat, Bill Bowden, Department of Agriculture; Lisa Brennan, CSIRO Brisbane 17. Automatic guidance and wheat row position: On-row versus between-row seeding at various rates of banded P fertilisers, Tony J. Vyn1, Simon Teakle2, Peter Norris3and Paul Blackwell4,1Purdue University, USA; 2Landmark; 3Agronomy for Profit; 4 Department of Agriculture 18. Assessing the sustainability of high production systems (Avon Agricultural Systems Project), Jeff Russell and James Fisher, Department of Agriculture, Roy Murray-Prior and Deb Pritchard, Muresk Institute; Mike Collins, ex WANTFA, 19. The application of precision agriculture techniques to assess the effectiveness of raised beds on saline land in WA, Derk Bakker, Greg Hamilton, Rob Hetherington, Andrew Van Burgel and Cliff Spann, Department of Agricultur

Crop Updates 2005 - Katanning

This session covers twenty five papers from different authors KEYNOTE How Farmers Can Work Together for a More Sustainable and Profitable Business, Brian McAlpine Farmer, Nuffield Scholar GENERAL 2005 Seasonal Outlook, David Stephens and Nicola Telcik, Department of Agriculture Essentials for cereal leaf disease management, K. Jayasena, R. Loughman, G. Thomas, C. Beard, and B. Paynter, Department of Agriculture Benefits to the grower of grain licensing, Colin Mann, Grain Licensing Authority SOIL & NUTRIENTS The effect of higher nitrogen fertiliser prices on rotation and fertiliser strategies in cropping systems, Ross Kingwell, Department of Agriculture Effect of stubble burning and seasonality on microbial processes and nutrient cycling, Francis Hoyle, University of Western Australia Soil Biology and Crop Production in Western Australian Farming Systems, D.V. Murphy, N. Milton, M. Osman, F.C. Hoyle, L.K Abbott, W.R. Cookson and S. Darmawanto, University of Western Australia Nutrient Management to get optimal production, Bill Bowden, Department of Agriculture OTHER CROPS Which malting barley variety and why? Blakely Paynter, Department of Agriculture KASPA AND OTHER NEW PULSE VARIETIES, 1. New Pulse varieties and where they fit in, K. Regan, P. White, Department of Agriculture & CLIMA, K. Siddique, CLIMA, K. Adhikari, Department of Agriculture & CLIMA, M. Harries, CLIMA Kaspa in the WA Grain Belt 2003-2004, Ian Pritchard, Department of Agriculture New annual pastures for Mediterranean farming systems, Angelo Loi, Phil Nichols, Clinton Revell & David Ferris, Department of Agriculture Challenging herbicide resistant ryegrass, Bill Roy, Agricultural Consulting & Research Services Pty.Ltd WEED MANAGEMENT Ingest, incinerate or invert? The pro’s and con’s of 3 weed seed removal tactics, Sally Peltzer1, Dave Minkey1 and Michael Walsh2 Department of Agriculture 1 and Western Australian Herbicide Resistance lnitiative2 A good use guide for pre-emergent herbicides, Alexandra Douglas, Department of Agriculture OTHER USEFUL INFORMATION 17.Growing season outlook, Meredith Fairbanks, Ian Foster, Geraldine Pasqual, David Stephens, Nicola Telcik, David Tennant, Department of Agriculture 18. Status Of Department Of Agriculture Western Australia Crop Varieties 19. Seed Licensee Details 20. Gene technology for growers. What is it? How does it Work? Belinda Barr, Australian Centre for Plant Functional Genomics, Dr Heather Bray, Molecular Plant Breeding Cooperative Research Centre. 21. Agronomic package for EGA Eagle Rock, Steve Penny, Department of Agriculture 22. Nutrient timing and requirements for increased crop yields in the high rainfall cropping zone, Narelle Hill, Ron McTaggart, Dr. Wal Anderson and Ray Tugwell Department of Agriculture 23. Insect contamination of cereal grain at harvest, Svetlana Micic and Phil Michael, Department of Agriculture 24. Crop leftovers: what’s in stubble for sheep? Roy Butler and Keith Croker, Department of Agriculture 25. Mandelup – Narrow-leafed lupi

Atlantic Water advection versus sea-ice advances in the eastern Fram Strait during the last 9 ka - multiproxy evidence for a two-phase Holocene

A sediment core from the West Spitsbergen continental margin was studied to reconstruct climate and paleoceanographic variability during the last ~9 ka in the eastern Fram Strait. Our multiproxy evidence suggests that the establishment of the modern oceanographic configuration in the eastern Fram Strait occurred stepwise, in response to the postglacial sea-level rise and the related onset of modern sea-ice production on the shallow Siberian shelves. The late Early and Mid Holocene interval (9 to 5 ka) was generally characterized by relatively unstable conditions. High abundance of the subpolar planktic foraminifer species Turborotalita quinqueloba implies strong intensity of Atlantic Water (AW) inflow with high productivity and/or high AW temperatures, resulting in a strong heat flux to the Arctic. A series of short-lived cooling events (8.2, 6.9. and 6.1 ka) occurred superimposed on the warm late Early and Mid Holocene conditions. Our proxy data imply that simultaneous to the complete postglacial flooding of Arctic shallow shelves and the initiation of modern sea-ice production, strong advance of polar waters initiated modern oceanographic conditions in the eastern Fram Strait at ~5.2 ka. The Late Holocene was marked by the dominance of the polar planktic foraminifer species Neogloboquadrina pachyderma, a significant expansion of sea ice/icebergs, and strong stratification of the water column. Although planktic foraminiferal assemblages as well as sea surface and subsurface temperatures suggest a return of slightly strengthened advection of subsurface Atlantic Water after 3 ka, a relatively stable cold-water layer prevailed at the sea surface and the study site was probably located within the seasonally fluctuating marginal ice zone during the Neoglacial period