About the Initiative
The Team
Research Programs
News & Views
Publications
RIM & WEEDEM Models
Extension
Links
Contact
Autumn 2006
WAHRI NEWSAre growers successfully managing herbicide resistant annual ryegrass? A recent study aimed to test whether herbicide resistance in annual ryegrass (Lolium rigidum) has led to greater population densities of this weed in cropping paddocks. The study examined the extent to which the costs of the most common form(s) of herbicide resistance in WA cropping paddocks can be attributed to higher weed densities affecting crop yield; or whether growers have maintained control of resistant weed populations. The results showed that the density of annual ryegrass in Western Australian cropping paddocks is generally not higher if the population is herbicide resistant. Thus, herbicide resistant ryegrass is being managed by WA growers. more Drivers of no-till adoption A recent study identified the key factors that influence the rate of no-till adoption across the southern Australian cropping regions. This information can be used to assist the many research, extension and grower organisations working to increase the sustainable use of no-till cropping systems. Several R,D&E opportunities exist to increase uptake of no-till in southern Australia however, weed management is a dominant factor affecting the sustainability of extensive no-till use. more Do herbicide resistant wild radish populations look different? Researcher, Michael Walsh found that there was no correlation between the resistance status and flower colour of wild radish. Biotypes of phenoxy herbicide resistant and susceptible wild radish populations were grown under the same environmental conditions and parameters of biomass, flower, colour, and seed production were measured in an attempt to identify distinguishing characteristics of resistant populations. more Does crop topping affect glyphosate and paraquat resistant annual ryegrass? Research by Emma Glasfurd, Michael Walsh and Kathryn Steadman has shown that crop topping with paraquat and glyphosate was found to be ineffective when used on annual ryegrass populations with resistance to these herbicides. Crop-topping had no effect on seed production, seed viability or seedling vigour of resistant populations. The possibility for resistance gene movement via pollen flow from paraquat and glyphosate resistant populations to susceptible annual ryegrass plants was also investigated. more Differential tolerance of lupins and chickpeas to herbicides that control wild radish Researchers Ping Si, Michael Walsh and Mark Sweetingham are researching the tolerance of lupin and chickpea germplasm to a range of alternate broadleaf herbicides to identify potential alternate herbicide chemistry that can be used for the control of wild radish in pulse crops. Preliminary studies identified that there was differential tolerance of some herbicides screened. For more information contact Michael Walsh New discovery grant for seed dormancy An ARC discovery grant has been awarded to Powles and Steadman along with International collaborators R Benech-Arnold (Argentina), H Hilhorst (The Netherlands), and P Toorop (UK) to examine the role for phytochrome in regulating annual ryegrass seed dormancy release. more Can annual ryegrass resistance 'jump the fence'? WAHRI researcher Roberto Busi from the University of Turin is researching the distance that ryegrass pollen can successfully carry herbicide resistance genes to cross pollinate susceptible ryegrass plants. This study was conducted in 2005 at Salmon Gums where herbicide susceptible plants were placed in a number of locations in both cropping & pasture paddocks and native bush areas to examine if they are able to be cross pollinated by herbicide resistant plants in neighboring areas. Seeds were collected from experimental plants at the end of the season and will be screened in the 2006 growing season. For more information, contact Roberto Busi Will low rates of glyphosate lead to the evolution of resistance? Roberto Busi is investigating the effects of low glyphosate use rates on the potential for glyphosate resistance development in ryegrass. Neve and Powles (Theoretical & Applied Genetics, 2005) demonstrated that selection of a diclofop-methyl resistant L. rigidum population is possible after repeatedly selecting a susceptible population with reduced diclofop-methyl rates. The aim of this study is to explore the likelihood of the same phenomena occurring with use of low rates of glyphosate: i.e. can exposure of a population of susceptible L. rigidum individuals to glyphosate rates lower than the recommended rate result in evolution towards resistance? For more information, contact Roberto Busi WA study of herbicide resistance in wild oats Reports of large wild oat populations and resistance problems are increasing in WA. Populations collected from a random survey carried out by WAHRI in 2005, will be screened to a number of herbicides over the 2006 growing season. Results will be available late 2006. For more information contact Mechelle Owen Glyphosate resistance confirmed at new sites Glyphosate resistant ryegrass has been confirmed at 10 new locations in Australia but no new cases have been confirmed in WA. The new populations are now listed on the Australian Glyphosate Resistance Register, bringing the total number of populations to 54, with 24 of the cases in broadacre cropping. All are in annual ryegrass. Glyphosate Resistance: Frequently Asked Questions The national Glyphosate Sustainability Working Group, an initiative involving research institutions and herbicide companies from around Australia, has developed a set of easy-to-follow answers to commonly asked questions relating to glyphosate resistance, including what to do if you suspect glyphosate resistance. These can be found on the GSWG website together with the Australian Glyphosate Resistance Register which documents the confirmed glyphosate resistant populations in Australia. http://www.weeds.crc.org.au/glyphosate Multiple resistant wild radish and trifluralin resistant annual ryegrass populations are increasing in WA Wild radish: New survey results based on random collections from 503 paddocks show the level of resistance to chlorsulfuron (Glean) has increased 3 fold over the past 4 years, and of particular concern is the identification of populations developing resistance to Atrazine and 2,4-D-amine. more Tetraploid ryegrass for WA? A novel way of 'regressing' herbicide resistance genes by planting herbicide susceptible 'tetraploid' ryegrass into a resistant diploid population could be a way of defeating herbicide resistance while maintaining a productive pasture phase. more New appointments at WAHRI David Minkey has joined WAHRI as leader of the WAHRI extension program. David has just completed his PhD in predation by ants as a weed control agent. David has spent many years working on herbicide related projects at the Department of Agriculture. He continues his work in with the Department of Agriculture, and, as well in WAHRI. At WAHRI, David is involved with projects such as the delivery of resistance management workshops and working with other grower, research and extension groups in WA to deliver herbicide resistance research information. David can be contacted on 6488 7872 or by dminkey@plants.uwa.edu.au Joel Torra from spain is visiting WAHRI for 10 months as part of his PHD on the integrated control of herbicide resistant populations of corn poppy Papaver rhoeas. He has been studying the biology and management of this crop weed in Spanish cereal cropping at the University of Lleida, Dept. of Hortofruticultura in Spain. At WAHRI, Joel is interacting with researchers on a range issues of herbicide resistance in plants, including adapting the RIM model for poppy management. RIM in national workshops for advisors and growers The computer model Resistance Integrated Management program (RIM) has been used extensively throughout Victoria as part of the DPI State Focus project. Over 250 growers and advisors used RIM as part of the program. RIM sessions are also part of a national IWM training program being conducted for advisors this year through the CRC Weeds and ICAN. For more information on organising a workshop using RIM for your group contact Robert Barrett Lennard There are 5 students completing their 4th year research projects with WAHRI in 2006. The students and their research projects are outlined below: Tarnya Fowler - Evaluation of a potential new ryegrass selective herbicide for WA wheat cropping systems. Jason Ellerton - Development of a chaff separation system that enables more efficient chaff processing during the harvest operation. Matt Willis - Does liming limit the growth and development of wild radish. Natalie Maguire - Evaluation of the competitive effects of 2,4-D resistant wild radish on wheat. Jared Nelson - Barley grass resistance to Monzaź (sulfosulfuron) Latest WAHRI Journal Articles 2006 D'Emden, F. H., Llewellyn, R. S. and Burton, M.P. (2006) Adoption of conservation tillage in Australian cropping regions: An application of duration analysis. Technological Forecasting and Social Change, 73 (in press). Llewellyn, R.S. and Allen, D.M. (2006). Expected mobility of herbicide resistance via weed seeds and pollen in a Western Australian cropping region. Crop Protection, 25, 520-526 Llewellyn, R.S, Lindner, R.K., Pannell, D.J., Powles, S.B (2006) Perceptions determining the adoption of integrated weed management. Agricultural Economics (accepted) Llewellyn. R.S., Lindner, R.K., Pannell, D.J. Powles, S.B. (2006) The influence of extension on learning and doing. Agricultural Systems. (accepted) Michael, P., Steadman, K., and Plummer, J. (2006) Limited eco-clinal variation found in malva parviflora (small flowered mallow) across the mediterranean-climatic agricultural region of Western Australia. Australian Journal of Agricultural Research, 57 (7) (in press) Michael, P., Steadman, K., Plummer, J., and Vercoe, P. (2006) Sheep rumen digestion and transmissions of weedy malva parviflora seeds. Australian Journal of Experimental Agriculture, 46 (10) (in press) Pederson BP, Neve PB, Andreason C & Powles SB (2006). Ecological fitness of a glyphosate resistant Lolium rigidum biotype: Growth, competitiveness and seed production along a competition gradient. Basic and Applied Ecology, (In press) Steadman KJ, Eaton DM, Plummer JA, Ferrris DG & Powles SB (2006) Late season non-selective herbicide application reduces Lolium rigidum seed dormancy and seed fitness as well as seed numbers. Australian Journal of Agriculture Research, 57, 133-141. Walsh, M. and Minkey, D. (2006) Wild radish (Raphanus raphanistrum L.) development and seed production in response to time of emergence, crop-topping and sowing rate of wheat. Plant Protection Quarterly. (In press) Zhang, X., Powles. S.B. (2006) The molecular basis for resistance to aryloxyphenoxypropionate and cyclohexanedione acetyl co-enzyme A inhibiting herbicides in two ACCase target based resistant biotypes of L. rigidum. Planta, 223 (3), 550-557 2005 Delye, C., Zhang, X., Severine, M., Annick, M., Matejicek, A., Powles, S.B. (2005) Molecular basis for sensitivity to acetyl-coenzyme A carboxylase inhibitors in black-grass (Alopecurus myosuroides Huds.) Plant Physiology:137, 794-806 Llewellyn, R. S., Pannell, D. J., Lindner, R. K., Powles, S. B. (2005). Targeting key perceptions when planning and evaluating extension. Australian Journal of Experimental Agriculture. 45 (12) 1627-1633.. Maneechote, C., Samanwong, S., Zhang, X., Powles, S.B. (2005) Resistance to ACCase inhibiting herbicides in a Thailand population of Leptochloa chinensis L. Weed Research, 53, 290-295. Monjardino, M., Pannell, D. J. and Powles, S. B. (2005) The economic value of glyphosate-resistant canola in the management of two widespread crop weeds in a Western Australian farming system. Agricultural Systems, 84 (3) 297-315. Neve, P & Powles SB (2005) Recurrent selection with reduced herbicide rates results in the rapid evolution of herbicide resistance in Lolium rigidum. Theoretical and Applied Genetics, 110, 1154-1166. link Neve P & Powles SB (2005) High survival frequencies at low herbicide use rates in populations of Lolium rigidum result in rapid evolution of herbicide resistance. Heredity, 95 (6), 485-492. Preston, C., Soar, C.J., Hidayat,I., Greenfield K.M., and Powles, S.B. (2005) Differential translocation of paraquat in paraquat-resistant populations of Hordeum leporinum. Weed Research, 45, 289-295. Vila-Aiub, M.M., Neve, P., Steadman, K.J., Powles, S.B. (2005) Ecological fitness of a multiple herbicide resistant Lolium rigidum population: Dynamics of seed germination and seedling emergence of target-site versus metabolism-based resistant and susceptible phenotypes. Journal of Applied Ecology, 42, 288-298. Vila-Aiub MM, Neve P & Powles SB. (2005) Fitness Costs of Evolved Herbicide Resistance. Encyclopedia of Pest Management, Marcel Dekker Inc., New York, (in press). Vila-Aiub MM, Neve P & Powles SB .(2005) Resistance costs of a cytochrome P450 herbicide metabolism mechanism but not an ACCase target site mutation in a multiple resistant Lolium rigidum population. New Phytologist, 167, 787-796. Walsh, M.J., Minkey, D.M., Powles, S.B. (2005) Field evaluation of preseason applications of residual herbicides to control annual ryegrass (Lolium rigidum Gaud.). Plant Protection Quarterly, 20 (4), 133-139. Weersink, A., Llewellyn, R.S., Pannell, D.J. (2005). Economics of pre-emptive management to avoid weed resistance to glyphosate in Australia. Crop Protection, 24 (7), 659-665. link to pdf For a list of the other WAHRI journal articles, click here News & Views is edited by Mechelle Owen & David Minkey
|
