Herbicide Resistance

  • Published on
    10-Jan-2016

  • View
    37

  • Download
    0

Embed Size (px)

DESCRIPTION

Herbicide Resistance. Discussion Topics What is resistance? What causes resistance?. Terminology. Mode of Action Codes ACCase inhibition ALS inhibition Microtubule assembly inhibition Synthetic auxin PS II inhibition, not groups 6 or 7 PS II inhibition, not groups 5 or 7 - PowerPoint PPT Presentation

Transcript

<p>Slide 1</p> <div><p>Herbicide Resistance</p></div> <div><p> Discussion Topics</p><p>What is resistance?</p><p>What causes resistance?</p></div> <div><p>2</p><p>2</p></div> <div><p>Terminology</p></div> <div><p>3</p></div> <div> Sites of ActionInhibition of ACCaseInhibition of ALSInhibition of PS IIPS I electron diversionInhibition of PPOBleaching: inhibition of carotenoid biosynthesis at PDSBleaching: inhibition of HPPDBleaching: inhibition of carotenoid biosynthesis, unknown targetInhibition of EPSPSInhibition of glutamine synthetaseMicrotubule assembly inhibitionInhibition of long-chain fatty acid synthesisInhibition of cell wall synthesisInhibition of lipid synthesis; not ACCase inhibitionSynthetic auxinsInhibition of auxin transportUnknown</div> <div>WSSA Code Site of Action1Inhibition of ACCase2Inhibition of ALS5Inhibition of PS II22PS I electron diversion14Inhibition of PPO12Bleaching: inhibition of carotenoid biosynthesis at PDS27Bleaching: inhibition of HPPD13Bleaching: inhibition of carotenoid biosynthesis, unknown target9Inhibition of EPSPS10Inhibition of glutamine synthetase3Microtubule assembly inhibition15Inhibition of long-chain fatty acid synthesis20 and 21Inhibition of cell wall synthesis8Inhibition of lipid synthesis; not ACCase inhibition4Synthetic auxins19Inhibition of auxin transport17Unknown</div> <div><p>9</p></div> <div> From 2011* NC AgChem Manual (&gt;150 entries)Table 8-11. Herbicide Modes of Action.Brand names Active ingredient(s)Chemical familyMode of ActionAAtrexatrazineTriazine5AccentnicosulfuronSulfonylurea2AimcarfentrazoneTriazolinone14AlachloralachlorChloroacetamide15AlanapnaptalamPhthalamate semicarbazone19ArrowClethodimCyclohexadione1AtrazineatrazineTriazine5Assure IIquizalofopAryloxyphenoxy-propionate1Axiomflufenacet + metribuzinOxyacetamide + triazinone15 + 5BackdraftGlyphosate + imazaquinGlycine + imidazolinone9 + 2* Revised annually.<p>Mode of Action Codes</p><p>ACCase inhibition</p><p>ALS inhibition</p><p>Microtubule assembly inhibition</p><p>Synthetic auxin</p><p>PS II inhibition, not groups 6 or 7</p><p>PS II inhibition, not groups 5 or 7</p><p>PS II inhibition, not groups 5 or 6</p><p>Lipid synthesis inhibition, not ACCase inhibition</p><p>EPSP synthase inhibition</p><p>Glutamine synthase inhibition</p><p>Carotenoid biosynthesis inhibition at PDS</p><p>Carotenoid biosynthesis inhibition, unknown target</p><p>PPO inhibition</p><p>Inhibition very long-chain fatty acids</p><p>Unknown MOA</p><p>Auxin transport inhibition</p><p>PS I electron diversion</p><p>Inhibition of HPPD</p></div> <div><p>12</p><p>12</p><p>12</p></div> <div><p> Herbicide Resistance Defined</p><p> (WSSA definition)</p><p>Inherited ability of a biotype* of a weed to surviveand reproduce following exposure to a dose of herbicide normally lethal to the wild type.</p><p> *Biotype is a subset of the population having </p><p> some genetically controlled characteristic not </p><p> common to the population as a whole</p></div> <div><p>13</p><p>13</p></div> <div><p> Herbicide Resistance Defined</p><p> (WSSA definition)</p><p>Inherited ability of a biotype of a weed to surviveand reproduce following exposure to a dose of herbicide normally lethal to the wild type.</p></div> <div><p>14</p><p>14</p></div> <div><p> Herbicide Resistance vs Tolerance </p><p>Resistance: herbicide used to kill that weed; it no</p><p>longer does; we have selected for </p><p>resistance. </p><p>Example: Hoelon and ryegrass</p><p>Tolerance:the herbicide never did kill that species.</p><p> Example: 2,4-D and ryegrass</p></div> <div><p>15</p><p>15</p></div> <div><p>Cause of Herbicide Resistance</p><p> Herbicides do not create resistance.</p><p> Herbicides can select for resistant</p><p> individuals already in the population. </p></div> <div><p>16</p><p>16</p></div> <div><p> Resistant individuals initially rare</p><p>Initial frequency of resistance: 1 in 100 thousand</p><p>1 in 1 million</p><p>1 in 10 million</p><p>1 weed/4.3 square feet = 10,000 weeds/acre</p><p> = 1,000,000 weeds/100 acres</p><p>Frequency of 1 in 1 million equal to one resistant</p><p> plant per 100 acres</p></div> <div><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>Hoelon-susceptible biotype </p><p>Hoelon-resistant biotype, Union Co.;</p><p>Treated with Hoelon </p><p>Group 1, ACCase inhibitor </p><p>Hoelon-resistant biotype, Union Co.; Treated with Axial </p><p>Group 1, ACCase inhibitor</p><p>Example of Cross Resistance</p><p> Italian ryegrass</p></div> <div><p>20</p></div> <div><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>Hoelon-susceptible biotype </p><p>Hoelon-resistant biotype</p><p>Treated with Hoelon </p><p>ACCase inhibitor, Group 1 </p><p>Hoelon-resistant biotype</p><p>Treated with Osprey </p><p>ALS inhibitor, Group 2</p><p>0X 1/4X 1/2X 1X 2X 4X 8X 16X 32X</p><p>Example of Multiple Resistance:</p><p>Italian Ryegrass</p></div> <div><p>26</p><p>26</p></div> <div><p> Quiz</p><p>Multiple resistance is greater concern </p><p>than cross resistance.</p><p>Why?</p></div> <div><p> Discussion Topics</p><p>What is resistance?</p><p>What causes resistance?</p><p>What is the extent of resistance?</p><p>What species have resistant biotypes?</p></div> <div><p>28</p><p>28</p></div> <div><p>ACY 2008</p><p>ALS inhibitors</p><p>PS II inhibitors (triazines)</p><p>ACCase inhibitors</p><p>Glyphosate</p><p>DNAs</p><p>Ureas/amides</p><p>Auxins</p><p>Arsenicals</p><p>Thiocarbamates</p><p>PPO inhibitors</p><p>Carotenoid biosyn. inhibitors</p><p>Nitriles</p><p>Herbicide Resistance in US by Site of Action*</p><p>Paraquat</p><p>HPPD inhibitors</p><p>*Current as of Dec. 6, 2010</p><p>Resistance reported with 14 SOAs and 76 species;</p><p>128 species by SOA combinations, due to multiple resistance</p></div> <div><p>29</p><p>29</p><p>29</p><p>29</p></div> <div><p>Glyphosate-resistant biotypes in U.S.</p></div> <div><p>Glyphosate-resistant biotypes in U.S.</p></div> <div><p> Glyphosate-Resistant Weeds in the US</p><p>7 Broadleaf weeds 5 Grasses</p><p>Palmer amaranthItalian ryegrass</p><p>Tall waterhempRigid ryegrass</p><p>Common ragweedJohnsongrass</p><p>Giant ragweedGoosegrass</p><p>Hairy fleabaneAnnual bluegrass</p><p>Horseweed</p><p>Kochia</p></div> <div>Examples of glyphosate multiple resistance in USPalmer amaranthglyphosate and ALS inhibitorsHorseweedglyphosate and ALS inhibitorsglyphosate and paraquatCommon ragweedglyphosate and ALS inhibitorsGiant ragweedglyphosate and ALS inhibitorsHairy fleabaneglyphosate and paraquatTall waterhempglyphosate, ALS inhibitors, and PPO inhibitors</div> <div><p>Glyphosate-</p><p>Resistant Weeds</p><p>in NC</p></div> <div><p>34</p><p>34</p></div> <div><p> Discussion Topics</p><p>What is resistance?</p><p>What causes resistance?</p><p>What is the extent of resistance?</p><p>What species have resistant biotypes?</p><p>Impacts of herbicide resistance?</p></div> <div><p>35</p><p>35</p></div> <div><p>Impacts of Herbicide Resistance</p><p>Increased cost of weed management; reduced profitability</p><p>Increased complexity of weed management</p><p>Fewer herbicide options</p><p>Fewer crop options</p><p>Compromise conservation tillage</p><p> Impacts of Herbicide Resistance</p><p>Increased cost of weed management; </p><p> reduced profitability</p><p>Increased complexity of weed management</p><p>Fewer herbicide options</p><p>Fewer crop options</p></div> <div><p>36</p><p>36</p></div> <div><p>Impacts of Herbicide Resistance</p><p>Increased cost of weed management; reduced profitability</p><p>Increased complexity of weed management</p><p>Fewer herbicide options</p><p>Fewer crop options</p><p>Compromise conservation tillage</p><p> Impacts of Herbicide Resistance</p><p>Increased cost of weed management; </p><p> reduced profitability</p><p>Increased complexity of weed management</p><p>Fewer herbicide options</p><p>Fewer crop options</p><p>Compromise conservation tillage</p></div> <div><p>37</p><p>37</p></div> <div><p> Discussion Topics</p><p>What is resistance?</p><p>What causes resistance?</p><p>What is the extent of resistance?</p><p>What species have resistant biotypes?</p><p>Impacts of herbicide resistance?</p><p>Basics of resistance management</p></div> <div><p>38</p><p>38</p></div> <div><p>How does herbicide resistance develop? </p><p> Prerequisites for Resistance</p><p> At least one resistant plant must be present</p><p>2.Selection pressure must be put on that resistant plant</p></div> <div><p>39</p><p>39</p></div> <div><p> Herbicide Resistance Management</p><p>The focus must be on </p><p>reducing selection pressure.</p></div> <div><p>40</p><p>40</p><p>40</p></div> <div><p>Diversity in management options reduces </p><p>selection pressure on herbicides.</p></div> <div><p>42</p><p>42</p></div> <div><p>Weed Management in Cotton: Before RR</p><p> Conventional tillage</p><p> PPI and PRE herbicides</p><p> Early POST or POST-directed herbicides</p><p> Late POST-directed herbicides</p><p> Cultivation</p></div> <div><p>Weed Management in Cotton: with RR</p><p> No-till or strip-till</p><p> No cultivation</p><p> No PPI herbicide; little to no PRE</p><p> Multiple in-crop Roundup applications</p><p> Very little other chemistry</p></div> <div><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p><p> Minimize seed bank; avoid seed production</p></div> <div><p>45</p><p>45</p></div> <div><p> Impact of Crop Rotation and Good Control in Rotational Crop</p><p> (whole field in soybean in 2009; all treated alike in 2009)</p><p>Carthage, NC 2009</p></div> <div><p>46</p><p>46</p><p>46</p></div> <div><p> Impact of Crop Rotation and Good Control in Rotational Crop</p><p> (whole field in soybean in 2009; all treated alike in 2009)</p><p>Carthage, NC 2009</p><p>Soybean</p><p>2008</p><p>Tobacco</p><p>2008</p></div> <div><p>47</p><p>47</p><p>47</p></div> <div><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p><p> Minimize seed bank; avoid seed production</p><p> Think whole-farm</p><p>Good control in all crops in rotation</p><p>Avoid seed production on ditchbanks, turnrows</p><p>Avoid seed movement </p></div> <div><p>48</p><p>48</p></div> <div><p>Herbicide Resistance Management</p><p> Minimize seed bank</p><p> Do not depend on a single herbicide (or a single SOA) </p><p> Multiple SOAs within a crop, starting with a PRE or Preplant</p><p> Crop rotation, multiple and different SOAs</p><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p></div> <div><p>49</p><p>49</p></div> <div><p>Herbicide Resistance Management</p><p> Minimize seed bank</p><p> Do not depend on a single herbicide (or SOA) </p><p>Multiple SOAs within a crop, starting with a PRE.</p><p>Crop rotation, with different SOAs</p><p> Use full rates, including sequentials and tank mixes</p><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p></div> <div><p>50</p><p>50</p></div> <div><p>Herbicide Resistance Management</p><p> Minimize seed bank</p><p> Do not depend on a single herbicide (or SOA) </p><p>Multiple SOAs within a crop, starting with a PRE.</p><p>Crop rotation, with different SOAs</p><p> Use full rates, including sequentials and tank mixes</p><p> Timely POST application</p><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p></div> <div><p>51</p><p>51</p></div> <div><p>This is not a 4-inch pigweed!</p></div> <div><p>Herbicide Resistance Management</p><p> Minimize seed bank</p><p> Do not depend on a single herbicide (or SOA) </p><p>Multiple SOAs within a crop, starting with a PRE.</p><p>Crop rotation, with different SOAs</p><p> Use full rates, including sequentials and tank mixes</p><p> Timely POST application</p><p> Start clean</p><p>Herbicide Resistance Management</p><p> (Reducing selection pressure)</p></div> <div><p>53</p><p>53</p></div> <div><p> Minimize seed bank</p><p> Do not depend on a single herbicide (or SOA) </p><p>Multiple SOAs within a crop, starting with a PRE.</p><p>Crop rotation, with different SOAs</p><p> Use full rates, including sequentials and tank mixes</p><p> Timely POST application</p><p> Start clean</p><p> Take advantage of non-chemical, cultural practices where applicable (tillage, narrow rows, planting dates, cover crops, etc.) </p><p>Herbicide Resistance Management</p></div> <div><p>54</p><p>54</p></div> <div><p>&amp;</p></div> <div><p> Discussion Topics</p><p>What is resistance?</p><p>What causes resistance?</p><p>What is the extent of resistance?</p><p>What species have resistant biotypes?</p><p>Basics of resistance management</p><p>Management of glyphosate-resistant weeds in NC</p></div> <div><p>56</p><p>56</p></div> <div><p>Glyphosate-</p><p>Resistant Weeds</p><p>in NC</p></div> <div><p>57</p><p>57</p></div> <div><p> 96 oz Weathermax Untreated</p><p>Martin Co., NC 2006</p></div> <div><p>58</p></div> <div><p>Distribution of Glyphosate-Resistant Common Ragweed</p></div> <div><p>59</p><p>59</p></div> <div><p>60</p></div> <div><p>Grower Applied Glyphosate; Dead and Live Plants;</p><p>Union Co., NC. Spring, 2009.</p></div> <div><p>61</p><p>61</p></div> <div><p>Johnston Co.</p><p>susceptible</p><p>Stanley Co.</p><p>Union Co.</p><p>Edgecombe Co.</p><p>susceptible</p><p> Glyphosate rates, left to right, where 1X = 860 g/ha or 21.8 fl oz PowerMax</p><p> 0.063X, 0.125X, 0.25X, 0.5X, 1X, 2X, 4X, 8X</p><p>1X</p><p>1X</p><p>8X</p><p>8X</p><p>Dec. 2009</p></div> <div><p>62</p></div> <div><p>Distribution of Glyphosate-Resistant Italian Ryegrass</p></div> <div><p>63</p><p>63</p></div> <div><p>Burndown for Glyphosate-Resistant Ryegrass</p><p> If you suspect glyphosate resistance:</p><p>Minimum of 2 pt/A Gramoxone applied twice.</p><p>Better control if mixed with a Photosystem II inhibitor:</p><p> atrazine for corn; Direx for cotton;</p><p>linuron or metribuzin product for soybean </p></div> <div><p>64</p></div> <div><p>Gramoxone 3 pt Mar. 9 </p><p>PowerMax 22 oz Mar. 9 </p><p>Gramoxone 2 pt Mar. 9</p><p>Gram 2 pt + atrazine Mar. 24 </p><p>PowerMax 22 oz Mar. 9 </p><p>PowerMax 22 oz + atrazine Mar. 24</p><p>Untreated </p><p>C. Simpson Farm</p><p>Apr. 10, 2010</p><p>Union County</p></div> <div><p>65</p></div> <div><p>66</p><p>66</p></div> <div><p>Glyphosate-Resistant Horseweed </p><p> Initially found in 2003; resistant biotype spread quickly beginning in 2008; assume all horseweed in eastern NC is resistant.</p><p> Wind-borne seed; easily moves long distances.</p><p> Problem in no-till. Postemergence options limited. Focus on good burndown program.</p><p>Photo by R. Hayes</p></div> <div><p>67</p><p>67</p></div> <div><p> Burndown Program for</p><p>Glyphosate-Resistant Horseweed </p><p>Two components of burndown program:</p><p>1. Something to kill emerged horseweed</p><p>2. Something to give residual control</p></div> <div><p>68</p><p>68</p></div> <div><p> Burndown Programs for</p><p>Glyphosate-Resistant Horseweed </p><p>Two components of burndown program:</p><p>1. Something to kill emerged horseweed*</p><p>2. Something to give residual control</p><p>Programs:</p><p>Glyphosate + Clarity (1/2 pt)** + residual herbicide</p><p>Glyphosate + 2,4-D (2 pt)** + residual herbicide</p><p>*Best if applied while weed </p><p> still in rosette state</p><p>__________________________________</p><p> ** Waiting intervals required</p></div> <div><p>69</p><p>69</p></div> <div><p>Edgecombe Co., 2008</p><p>GR Horseweed</p><p>Roundup at burndown</p><p>Roundup + 2 pt 2,4-D</p><p>+ 2 oz Valor </p><p>at burndown</p></div> <div><p> In-Crop Control of </p><p>Glyphosate-Resistant Horseweed</p><p>Cotton:Ignite under hood (any variety)</p><p>Ignite overtop tolerant variety</p><p>Corn:Dicamba or 2,4-D</p><p>Ignite on LL hybrid</p><p>Soybean: FirstRate, horseweed &lt; 6 inches</p><p>Ignite overtop LL variety</p></div> <div><p>71</p><p>71</p></div> <div><p> Glyphosate-Resistant</p><p> Palmer Amaranth</p><p> Found in NC in 2005; now common </p><p> Spreading rapidly</p><p>- Equipment</p><p>- Pollen flow</p><p> Best to assume it is all glyphosate-resistant</p><p> ALS resistance also common in Palmer amaranth; multiple resistance in some populations</p><p> GR Palmer amaranth distribution</p></div> <div><p>73</p><p>73</p></div> <div><p>Palmer amaranth sampling, fall 2010</p><p>Palmer present</p><p>No Palmer found</p><p>Not surveyed</p></div> <div><p>What Makes Palmer Amaranth</p><p> Such a Bad Weed?</p><p> Heat and drought tolerant</p><p> High photosynthetic capacity</p><p> Rapid growth; large stature</p><p> Very prolific</p><p> Resistance trait transferred </p><p> via pollen</p></div> <div><p>4 in 52 hrs</p></div> <div><p>77</p></div> <div><p> Can have thousands of seed 99% control is a disaster</p><p> per square yard in seed bank;</p><p> hundreds emerge per square yard</p></div> <div><p>78</p><p>78</p></div> <div><p>80</p></div> <div><p> Untreated Atrazine-based program</p></div> <div><p>81</p></div> <div><p>82</p><p>82</p></div> <div><p>GR Palmer Amaranth Control in RR CottonSoutheast US Recommendations</p><p>Avoid cotton in badly infested fields; rotate out of cotton for a year or more and strive for good control in rotational crop; reduce seed bank</p></div> <div><p>83</p></div> <div>Palmer Amaranth Programs for CornPOSTPRERR CornLL CornConventionalBicepHalex GT + atrazineIgnite + atrazineCapreno + atrazineGuardsman MaxRoundup + atrazineClarity + atrazineHarness ExtraRoundup + Dual II Magnum*Laudis + atrazineLariatRoundup + Warrant*LexarRoundup + Clarity<p>*No activity on emerged glyphosate-resistant weeds.</p></div> <div>Palmer Amaranth Programs for SoybeansPPO PREsNon-PPO PREsPOSTAuthority MTZ + grass herbicideBoundaryRoundup + BlazerEnvive + ProwlCanopy + grass h...</div>