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2014 cca presentation- goondiwindii 16 july 2014 copy

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2014 cca presentation- goondiwindii 16 july 2014 copy

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2014 cca presentation- goondiwindii 16 july 2014 copy

  1. 1. Herbicide resistance in wild oats & barnyard grass & resistance testing Dr Peter Boutsalis, Dr Jenna Malone, Christopher Preston & Gurjeet Gill. School of Agriculture, Food and Wine University of Adelaide Plant Science Consulting
  2. 2. Why does herbicide resistance occur?  Herbicides don’t cause resistance!!  Resistance is naturally present.  Herbicides select and enrich resistance  Ryegrass/ wild radish- obligate outcrossing so combine weak resistance  strong resistance  Wild oats/ barnyard grass mostly self pollinate.
  3. 3. Frequency of resistance  Group A: 1 in 500,000 naturally resistant  Group B: 1 in 20,000 naturally resistant (25X)  Group M: very rare but its here!
  4. 4. Frequency of Group A Resistant Individuals in a 100 ha Paddock Plant Density 1 m-2 10 m-2 100 m-2 1000 m-2 Plants 1 million 10 million 100 million 1 billion Resistant Individuals 2 20 200 2000 (assume a frequency of 1 R/ 500,000 plants)  So a paddock with a low density of survivors may not look threatening but if they are resistant  resistant seedbank!!
  5. 5. If continuous use, how soon does resistance happen? - Rules of Thumb Herbicide Group Years to resistance B- Glean 4 A- Hoegrass 6-8 C- Simazine 10-15 D- Trifluralin 10-15 F- Brodal ~10 L- Sprayseed >12 M- Glyphosate ~15
  6. 6. Life Impact The University of Adelaide Resistance in wild oats? • 1000+ Group A resistant cases • Group B’s- few confirmed • Mataven (Group Z) • What is the information from random • surveys?
  7. 7. GRDC sponsored survey GOA 2013 – Wild oats  Survey area: Coonamble to Narromine, Nyngen to Coolah  40 wild oat samples  Trends- incidence of resistance: – Very low : Atlantis, Verdict, Select – Low : Axial – Medium : Mataven – High: Topik
  8. 8. Wild oat herbicide resistance How real is the threat ? NGA survey Oct 2007 (Richard Daniel) Acknowledgment: Bayer CropScience, Nufarm and Syngenta who all contributed to the cost of testing
  9. 9. How widely did we survey ? • Involved 34 agronomists from Sthn Qld to the Liverpool Plains and west to Walgett and Mungindi • 61 seed samples from ‘high risk’ situations (Paddocks with wild oat herbicide performance issues in 2007 or having previous concerns) • 36 seed samples from ‘random level’ situations (Nearly all paddocks unsprayed for wild oats in 2007. Best estimate of ‘average resistance levels’) • All samples tested by Peter Boutsalis (Plant Science Consulting) with a common range of 9 herbicides
  10. 10. When were herbicides applied ? Products Herbicide group (sub group) Application timing TriflurX + Avadex Xtra D + E Pre-emergent, directly on seed then covered with 1 cm soil, to simulate IBS Wildcat, Topik and Verdict A (fop) 3 leaf stageAxial A (den) Select A (dim) Atlantis B Mataven Z Jointing to first node, to simulate SST
  11. 11. Incidence (% of samples with ANY resistance) 0 20 40 60 80 100 Wildcat 300 mL/ha Topik 65 mL/ha Verdict 50 mL/ha Axial 150 mL/ha Mataven 1875 mL/ha Atlantis 330 mL/ha Select 175 mL/ha TriflurX + Avadex Xtra %ofsampleswithANYresistance High risk (61 samples) Random level (36 samples)
  12. 12. Were samples resistant to more than one herbicide ?
  13. 13. Frequency of multiple herbicide resistance 59% of ‘high risk’ samples had resistance to 3 or more different herbicides 0 20 40 60 80 100 0 1 2 3 4 5 6 7 8 Resistance to number of herbicides %ofsamples High risk (61 samples) Random level (36 samples) 15% of ‘high risk’ samples were NOT resistant to any herbicide 78% of ‘random level’ samples were NOT resistant to any herbicide
  14. 14. Conclusions 1. Herbicide resistant wild oats are a real and escalating issue in the north. 2. Testing of ‘escapes’ in individual paddocks MUST become a key management practice. Test to see what will WORK 3. No single product/ strategy will provide the solution
  15. 15. Life Impact The University of Adelaide Understanding Group A herbicide resistance Peter Boutsalis, Jenna Malone, Christopher Preston, Sam Kleemann, Gurjeet Gill School of Agriculture, Food & Wine, University of Adelaide,
  16. 16. Wild Oats resistance- Group A’s FOPS DEN DIM If resistant to below: Topik Verdict Targa Axial Achieve Select Factor Topik - ? ? ? ? ? ? Verdict R - R ? ? ? ? Targa R ? - ? ? ? ? Axial R ? ? - R ? ? Achieve R ? ? R ? - ? ? Select R ? ? ? ? - ? Factor R ? ? ? ? R? - Rate response: 150ml/ha Axial vs 300ml/ha Axial
  17. 17. Photos Axial regrowth 300 vs 150ml Axial Avadex
  18. 18. Wild oats resistance- Group B’s Sulfonylureas IMI’s TP’s If resistant to below: Hussar (ryegrass) Atlantis (wild oats) Intervix/ OnDuty Crusader Hussar - R? ? R? Atlantis R - ? R? Intervix (Clearfield) R R - R Crusader R R ? -
  19. 19. Mechanisms of resistance
  20. 20. Mechanisms of resistance How are resistant plants different to susceptible plants?  1. Metabolic resistance  2. Target site resistance  3. Uptake & translocation  4. Sequestration  5. Increased expression of target site - eg. glyphosate resistance in brome
  21. 21. Metabolic resistance  Plant enzymes detoxify the herbicides before they reach the target site  The herbicide will kill the plant if it reaches the target site in sufficient concentration  Occurs in wild oats, ryegrass Location of sensitive target site. Plant is resistant X Herbicide
  22. 22. Target Site Resistance • Some herbicides bind to single but different enzyme: – Group A (ACCase), – B (ALS), – C (PS2) , – M (EPSPS) • Variations in efficacy within a Group can occur eg. between Topik, Verdict, Axial, Achieve, Select.
  23. 23. Target Site Resistance • Herbicides are chemically different and bind to the target-site enzyme slightly differently • Different mutations change the shape of the target site affecting cross-resistance H2 H1 Target enzyme Target enzyme Target enzyme H2 H1 H2 H1
  24. 24. Group A target site- ACCase gene Group A biniding site
  25. 25. Group A resistance mutations 1781 1999 2027 2041 2078 2088 2096 Biotin carboxylase Biotin carrier Carboxyltransferase ACCase gene
  26. 26. Distribution & understanting of Group A resistance using DNA technology 2078 25 2041 3 2078, 2041 11 2078, 2088 5 2041, 1781 1 1781, 2041, 2078 1 2041, 2078, 2088 1 Paddock 1 Paddock 2 Paddock 3 ACCase Target site mutations
  27. 27. Life Impact The University of Adelaide Glyphosate Resistance Christopher Preston, Jenna Malone and Peter Boutsalis School of Agriculture, Food & Wine, University of Adelaide
  28. 28. Life Impact The University of Adelaide What we have so far Annual ryegrass Barnyard grass Liverseed grass Fleabane Windmill grass Great brome
  29. 29. Life Impact The University of Adelaide Glyphosate resistance in awnless BYG • 70 populations confirmed glyphosate resistant • Lots more unconfirmed • Cross-pollination low: 1.4% • Mechanisms of resistance • 1 = Target site resistant • 10 = ‘other’ mechanism • Temperature effects
  30. 30. Glyphosate resistant barnyard grass 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 2000 4000 Survival(%) Glyphosate (ml/ha) S A533.1 A1352.1 A491
  31. 31. Life Impact The University of Adelaide Temperature and glyphosate resistance • In some glyphosate resistant biotypes temperature affects efficacy. • Related with the resistance mechanism 20oC 30oC
  32. 32. Resistance Testing  Would you pay $300 to ensure you don’t choose the wrong herbicide??  Buy effective herbicides (save money)  Reduce crop competition yield  Reduce weed infestations restrict crop rotation choice  Avoid increase resistant seedbanks
  33. 33. “Know your enemy” Testing for Herbicide Resistance
  34. 34. What tests are there? 1. During the growing season • Syngenta Herbicide Resistance Quick-Test • Test for resistance on surviving weeds • Grasses mainly • 4-5 weeks 2. At end of season (pre-harvest) • Seed testing • 8-10 weeks • Dormancy breaking easy (wild radish, wild oats, ryegrass etc.) • Seedlings transplanted 3. Crop Seed Quality Testing • Germination, Vigor, TSW, • Clearfield testing- wheat/ barley/ canola PLANT SCIENCE CONSULTING www.plantscienceconsulting.com
  35. 35. Quick-Test: Monitoring: identify survivors Why has this individual survived and the others haven't? Is it resistant?
  36. 36. Post Plants
  37. 37. Growth stage = 1-2 leaf to advanced tillering Best stage is early tillering Rinse soil off roots Plants can be trimmed Leaves dry Add NO water Quick-Test: collect plants
  38. 38. Make cuttings
  39. 39. Cuttings and re-growth 1. Cuttings 2. Regrowth 5-10 days later 3. Spray Compared to Standard Resistant and Susceptible biotypes in every test
  40. 40. Assess 2-3 weeks after spray Test for any post emergence herbicide
  41. 41. Results using Seed Testing Herbicide Product Rate Herbicide Group Farmer paddock (g or ml/ha) Surviva l (%) Rating Verdict + 1% Hasten 85 A-FOP 70 RRR Select + 1% Hasten 200 A-DIM 20 R Hussar + 1% Hasten 200 B-SU 90 RRR Atrazine + 0.2% BS1000 2000 C 0 S Triflur X 1000 D 0 S
  42. 42. Results Ratings RRR RR R
  43. 43. For more information www.plantscienceconsulting.com.au

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