News and Views Winter 2012

If you experience difficulty viewing this message, you can view it online here. Winter 2012 Australian Herbicide Resistance Initiative School of Plant Biology University of Western Australia M086 35 Stirling Highway, Crawley WA 6009 www.ahri.uwa.edu.au Supported by GRDC In This Issue Harrington Seed Destructor goes commercial! AHRI wins ARC Linkage Grant – Identifying the biochemical and molecular bases of 2,4-D herbicide resistance in the economically important weed Raphanus raphanistrum (wild radish) AHRI releases two new videos under the mantra, ‘when on a good thing, don’t stick to it’ Apply now for the Graduate Student Award to attend the Global Herbicide Resistance conference Feb 2013 Council of Australasian Weed Societies (CAWS) Orator Dr Jason Norsworthy – Global Herbicide Resistance Challenge Conference Dr Busi wins Perth Marathon for a second time Ryegrass Integrated Management (RIM): WA’s favourite bio-economic model is revamped Harvest weed seed control fact sheet New Publications Harrington Seed Destructor goes commercial! One of the most anticipated technologies in Australian agriculture, the Harrington Seed Destructor (HSD), has progressed to commercial production with the Grains Research & Development Corporation (GRDC) awarding the license to de Bruin Engineering of Mount Gambier, South Australia. Funded by the GRDC, the HSD is the brainchild of WA grain grower and inventor Ray Harrington. The machine’s design was progressed by collaboration with Australian Herbicide Resistance Initiative (AHRI).  Please view paper Harrington Seed Destructor: A New Nonchemical Weed Control Tool for Global Grain Crops. Designed to destroy weed seeds in chaff during harvest, and thereby reducing the potential for weed growth, the first HSD is expected to be commercially available in time for the 2012 harvest. To view the full media release, please click here. AHRI wins ARC Linkage Grant – Identifying the biochemical and molecular bases of 2,4-D herbicide resistance in the economically important weed Raphanus raphanistrum (wild radish) AHRI resistance surveys (Walsh et al. 2007) confirmed an alarming increase in the number of cases of resistance to 2,4-D in wild radish in WA. AHRI has identified many 2,4-D resistant wild radish populations from the WA grain belt, and a new ARC Linkage project with Nufarm as industry partner, aims to identify the molecular and biochemical mechanism(s) endowing 2,4-D resistance in wild radish populations. The herbicide 2,4-D is very similar to auxin, an important and essential plant growth hormone that is present in all plants. Unravelling how wild radish becomes resistant to 2,4-D while retaining normal auxin activity poses a significant research challenge. Studies will investigate 2,4-D plant uptake and movement, the potential for resistant plants to metabolise 2,4-D, as well as its effectiveness at sites of action within the plant. The work aims to establish diagnostic tests for 2,4-D resistance in wild radish and other weed species. The ultimate aim of this research is to provide the underpinning science that will help contribute to the sustainability of the 2,4-D type herbicides in Australian agriculture. AHRI releases two new videos under the mantra, ‘when on a good thing, don’t stick to it’ As penicillin is to human health, so glyphosate is for weed control in global crops. A one in a hundred year chemical, glyphosate is a precious resource that needs to be conserved for future farmers, and future harvests. This is the message from Professor Stephen Powles, AHRI Director, in two newly released videos. Read full article   Apply now for the Graduate Student Award to attend the Global Herbicide Resistance conference Feb 2013 With a value of $AUS550, PhD students have the opportunity to apply for the Graduate Student Award which reimburses all registration costs to the Global Herbicide Resistance Challenge Conference being held in the portside city of Fremantle, Perth, Western Australia from February 18-22, 2013. Read full article   Council of Australasian Weed Societies (CAWS) Orator Dr Jason Norsworthy – Global Herbicide Resistance Challenge Conference Dr Jason Norsworthy has been awarded the prestigious Council of Australasian Weed Societies (CAWS) Orator at the Global Herbicide Resistance Conference to be held in Fremantle in February 2013. Dr Norsworthy is Professor and Elms Farming Chair of Weed Science in the Crop, Soil and Environmental Sciences Department at the University of Arkansas. He teaches Principles of Weed Control and team teaches Colloquium and Integrated Pest Management and has authored or co-authored over 110 refereed journal publications and over 400 abstracts. Studying the evolution and spread of herbicide resistance in Southern United States cropping systems, specifically cotton, soybean, rice, and corn, his research has centred on developing strategies to manage resistant weeds and reduce the risk of herbicide resistance.   He has documented seven new herbicide-resistant weeds in the region over the past six years. Read full article   Dr Busi wins Perth Marathon for a second time AHRI’s Dr Roberto Busi won the 2012 Perth Marathon on the 17th June in an outstanding time of two hours and 32 minutes. From a field of over 600 contestants, Roberto ran a solid race and beat his nearest competitor by more than seven minutes. An admirable effort and another win adding to the already impressive record of distance running wins by Roberto. Ryegrass Integrated Management (RIM): WA’s favourite bio-economic model is revamped RIM is an innovative modelling tool for broad acre cropping that enables users to simulate the effect of ryegrass control methods on cropping profitability. Designed for advisors and farmers as a user-friendly way of testing at paddock scale, RIM measures the effect of various control methods on ryegrass populations and paddock profitability. Now, with GRDC funding, AHRI Research Officer Myrtille Lacoste, supervised by Professor Stephen Powles, has upgraded RIM a decade after the model was first developed. Read full article Harvest weed seed control fact sheet Targeting weed seeds at harvest is a pre-emptive action against problematic annual weed populations infesting Australian crop production systems. Our most damaging crop weeds are annual species capable of establishing large persistent seed-banks. Fortunately for most of these problematic annual weed species seed bank decline is rapid. Consequently, without inputs a very large seed bank can be reduced to a very modest one in just a few years. Low weed seed bank levels allow easier and more effective weed control with a reduced risk of herbicide resistance development. Thus, effective weed management in productive cropping systems is reliant on preventing viable seed entering the seed-bank. For crop producers harvest weed seed control represents an opportunity to specifically target weeds during harvest preventing inputs to the weed seed bank. Towards this a number of systems have been developed over the past three decades that target the weed seed bearing chaff fraction during commercial grain crop harvest.   To read more go to Harvest weed seed control fact sheet (RIRDC) New Publications Harrington Seed Destructor: A New Nonchemical Weed Control Tool for Global Grain Crops Michael Walsh, Ray Harrington & Stephen Powles (Crop Science) Harvest weed seed control is a very important strategy in the integrated weed management (IWM) tool kit, and can be achieved by collecting chaff and processing it, or burning narrow windrows to reduce the weed seed burden. The Australian Herbicide Resistance Initiative’s (AHRI) latest paper, published in Crop Science, explores the previously unrealised opportunity of intercepting and destroying weed seeds that exit the grain harvester in the chaff fraction during harvest.  The Harrington Seed Destructor (HSD) provides over 90 per cent destruction of ryegrass, wild radish, wild oat, and brome grass seeds when utilised during the commercial harvest of wheat, barley and lupin crops. Extensive field trials of the HSD system are currently being conducted across a broad range of agricultural systems. The HSD system aims to have a dramatic impact on agriculture not only in Australia, but around the globe. Synergistic effects of atrazine and mesotrione on S and R wild radish (Raphanus raphanistrum) populations and the potential for overcoming resistance to triazine herbicides. Michael Walsh, Karrie Stratford, Kent Stone & Stephen Powles (Weed Technology) Earlier research by Sutton et al. (2002 Pest Management Science) and Hugie et al. (2008 Weed Science) established the powerful synergy achieved in a mixture of an HPPD and PS2 herbicide. This new AHRI research publication by Walsh et al. (2012 Weed Tech) confirms this synergy in the very economically damaging weed in Australia, wild radish. Sutton et al. (2002) also made the very important discovery that remarkably the HPPD/PS2 mixture is synergistic even on triazine resistant weed species. This was confirmed by Hugie et al. (2008) and also found in triazine resistant wild radish by Walsh et al. (2012). Commercially, HPPD plus PS2 herbicide mixtures are achieving synergy in various parts of the world. In Australia the wheat selective herbicide Velocity (Bayer) is a synergistic mixture of the HPPD herbicide pyrasulfatole and the PS2 herbicide bromoxynil.   Simulation modelling identifies polygenic basis of herbicide resistance in a weed population and predicts rapid evolution of herbicide resistance at low herbicide rates.  Crop Protection 2012, Vol 40, 114-120 Manalil S, Renton M, Diggle A, Busi R, Powles SB (2012) This paper utilises our PERTH resistance model (Renton et al 2011, Jnl. Theoretical Biology) and our field experiments on low herbicide dose (Manalil et al 2011, Weed Science) to model that low, below label, herbicide use rates can lead to rapid resistance evolution in cross pollinated Lolium.  This modelling analysis adds to our increasing biological data of the adverse impact of low, below label, herbicide use rates in resistance evolution in  genetically diverse, cross pollinated Lolium.   We emphasise that this low dose resistance evolution is much more likely in obligate cross pollinated species than in self-pollinated species, as cross-pollinated species can easily and additively accumulate gene traits through cross-pollination.    Of course, herbicide resistance evolution will occur at high herbicide use rates due to major effect genes but low, below label, herbicide use rates should be avoided as resistance evolution can be rapid and non-target site mechanisms such as enhanced metabolism are enriched which can endow resistance across dissimilar herbicide chemistries. This newsletter is brought to you by Australian Herbicide Resistance Initiative. To contact us, email: neree.martinez@uwa.edu.au. Forward our eNewsletter to a friend Click to Unsubscribe