Optimized Eric Johnson Weeds

Slide1: 

Stacking of Residual Herbicides. Eric Johnson1, J. R. Moyer, F.A. Holm, K. L., Sapsford, L.M. Hall, J.J. Schoneau, A. M. Smigielska, M.E. Kuchuran, and R.G. Hornford 1Scott Research Farm

What’s the issue?: 

What’s the issue? A number of soil residual herbicides with same mode of action (ALS inhibitors) introduced in the past 10-15 years. Droughts on prairies Concerns raised by industry agronomists about Everest (flucarbazone-sodium) on wheat – followed by Odyssey (imazamox:imazethapyr 1:1) on field pea. Injury more frequently observed on field pea when 2 used in succession.

Slide3: 

Everest Odyssey Everest

Residual Group 2 Herbicide Usage – Weed Survey Data 1996 - 2003: 

Residual Group 2 Herbicide Usage – Weed Survey Data 1996 - 2003

% of respondents that applied a residual ALS herbicidea, Weed Survey Questionnaire, Prairie Provinces, 2001-2003.: 

% of respondents that applied a residual ALS herbicidea, Weed Survey Questionnaire, Prairie Provinces, 2001-2003. aimazamethabenz, imazethapyr, imazethapyr:imazamox, flucarbazone-sodium, sulfosulfuron, and florasulam

Percentage of ALS soil residual herbicidesa that were applied in successive years, Weed Survery Questionnaire, Prairie Provinces, 2001-2003 : 

Percentage of ALS soil residual herbicidesa that were applied in successive years, Weed Survery Questionnaire, Prairie Provinces, 2001-2003 aimazamethabenz, imazethapyr, imazethapyr:imazamox, flucarbazone-sodium, sulfosulfuron, and florasulam

Slide7: 

a Other group includes: sulfosulfuron (sulfonylurea) flucarbazone-sodium (sulfonylamino carbonyltriazolinone) and florasulam (triazolopyrimidine sulfonanlide)

Slide8: 

Group 2 Repeat Application Study: 

Group 2 Repeat Application Study Is a crop predisposed to Group 2 injury if a residual Group 2 herbicide was applied the previous year? Does the repeated application of different Group 2 herbicides in two successive years result in additive or synergistic plant-back injury to susceptible crops grown in years three or four?

Herbicide Residue Stacking: 

Herbicide Residue Stacking 'The repeated application of different residual herbicides which results in additive or synergistic injury to rotational crops.'

Experiment 1: 

Experiment 1 Crop Sequence Year 1 – Field pea Year 2 – Wheat Year 3 – RR canola/ Clearfield canola Herbicide treatments Year 1– Non-Group 2 Check, Odyssey Year 2 – Non-Group 2 Check, Assert, Sundance, Everest, Frontline

Site Characteristics: 

Site Characteristics

Field pea – wheat – canola sequence: 

Field pea – wheat – canola sequence Year 2 – wheat results ('predisposition to injury' phase)

Graph explanation : 

Graph explanation Year 1 herbicide

Scott: 1st injury rating in spring wheat (7 DAT). 2003. : 

Scott: 1st injury rating in spring wheat (7 DAT). 2003.

Colby’s Equation: 

Colby’s Equation Expected Response (E) = X1 = growth as a percent of control with herbicide A Y1 = growth as a percent of control with herbicide B If Observed response andlt; Expected Response – antagonistic If Observed Response = Expected Response – additive If Observed Response andgt; Expected Response - synergistic

Predicted vs. Observed Growth Reduction (Based on Visual Injury Ratings 7 DAT) in Spring Wheat, Scott, SK. 2003: 

Predicted vs. Observed Growth Reduction (Based on Visual Injury Ratings 7 DAT) in Spring Wheat, Scott, SK. 2003 % Growth Reduction Odyssey- Assert Odyssey- Everest Odyssey- Sundance Odyssey- Frontline

Scott: 3rd injury rating in spring wheat (28 DAT). 2003. : 

Scott: 3rd injury rating in spring wheat (28 DAT). 2003.

Slide19: 

2003 - Photos taken about 14 DAT

Scott: Yield of spring wheat (bu/acre). 2003.: 

Scott: Yield of spring wheat (bu/acre). 2003. 2002 Odyssey vs. No Odyssey: p=0.02 * *

Predicted vs. Observed Yield Reduction in Spring Wheat, Scott, SK. 2003: 

Predicted vs. Observed Yield Reduction in Spring Wheat, Scott, SK. 2003 % Yield Reduction Odyssey- Assert Odyssey- Everest Odyssey- Sundance Odyssey- Frontline

Slide22: 

2004- Photos taken about 21 DAT

Scott: 3rd injury rating to spring wheat (28 DAT). 2004. : 

Scott: 3rd injury rating to spring wheat (28 DAT). 2004.

Scott: Yield of spring wheat (bu/acre). 2004.: 

Scott: Yield of spring wheat (bu/acre). 2004. 2002 Odyssey vs. No Odyssey: p= NS ab b b a b

Ellerslie: 2nd injury rating to spring wheat (7DAT). 2004. : 

Ellerslie: 2nd injury rating to spring wheat (7DAT). 2004.

Ellerslie: Yield of spring wheat. (bu/acre). 2003.: 

Ellerslie: Yield of spring wheat. (bu/acre). 2003. 2002 Odyssey: p=NS 2003 Group 2 = NS Interaction p=0.06

Saskatoon: Yield of spring wheat. (bu/acre). 2003.: 

Saskatoon: Yield of spring wheat. (bu/acre). 2003. 2002 Odyssey: p=0.03 Odyssey yield andgt; No Odyssey

Melfort: Yield of spring wheat. (bu/acre). 2003.: 

Melfort: Yield of spring wheat. (bu/acre). 2003. 2002 Odyssey: p=0.02 2003 Group 2: NS No interaction Yields on Odyssey Sign. Higher Than No Odyssey

Fairview: Yield of spring wheat. (bu/acre). 2003.: 

Fairview: Yield of spring wheat. (bu/acre). 2003. 2002 Odyssey: pandlt;0.01 Odyssey andgt; No Odyssey 2003 Group 2 = NS No interaction

Pea-Wheat-Canola Sequence: Wheat phase: 

Pea-Wheat-Canola Sequence: Wheat phase Odyssey application in the pea phase predisposed the wheat crop to post-emergence Group 2 injury at Scott. Only 1 site-year (out of 11) where injury resulted in an additive or synergistic yield reduction.

Field pea – wheat – canola sequence: 

Field pea – wheat – canola sequence Year 2 – canola results ('stacking' phase) Most responsive sites were dry in 2002 and 2003.

Slide32: 

Scott: 1st injury rating to Roundup ready canola. (7 DAE). 2004. : 

Scott: 1st injury rating to Roundup ready canola. (7 DAE). 2004. Year 1 herbicide

Scott: 3rd injury rating to Roundup ready canola. (28 DAE). 2004. : 

Scott: 3rd injury rating to Roundup ready canola. (28 DAE). 2004. Year 1 herbicide

Scott: Days to Flower - Roundup ready canola. 2004. : 

Scott: Days to Flower - Roundup ready canola. 2004. Year 1 herbicide * * * *

Scott: Yield of Roundup ready canola (bushel/acre). 2004.: 

Scott: Yield of Roundup ready canola (bushel/acre). 2004. Year 1 herbicide * *

Slide37: 

Slide38: 

Vanscoy: 2nd injury rating to Roundup ready canola. (14 DAE). 2004. : 

Vanscoy: 2nd injury rating to Roundup ready canola. (14 DAE). 2004. Year 1 herbicide

Vanscoy: Days to Flower - Roundup ready canola. 2004. : 

Vanscoy: Days to Flower - Roundup ready canola. 2004. Year 1 herbicide * *

Vanscoy: Yield of Roundup ready canola (bushel/acre). 2004.: 

Vanscoy: Yield of Roundup ready canola (bushel/acre). 2004. Year 1 herbicide * *

Fairview: 1st injury rating to Roundup ready canola. (7 DAE). 2004. : 

Fairview: 1st injury rating to Roundup ready canola. (7 DAE). 2004. Year 1 herbicide

Fairview: 3rd injury rating to Roundup ready canola. (28 DAE). 2004. : 

Fairview: 3rd injury rating to Roundup ready canola. (28 DAE). 2004. Year 1 herbicide

Fairview: Days to Flower - Roundup ready canola. 2004. : 

Fairview: Days to Flower - Roundup ready canola. 2004. Year 1 herbicide *

Fairview: Yield of Roundup ready canola (bushel/acre). 2004.: 

Fairview: Yield of Roundup ready canola (bushel/acre). 2004. 2002 Odyssey: p=NS 2003 Group 2 = NS No interaction

Ellerslie: Yield of Roundup ready canola (bushel/acre). 2004.: 

Ellerslie: Yield of Roundup ready canola (bushel/acre). 2004. 2002 Odyssey: p=NS 2003 Group 2 = NS No interaction

Melfort: Yield of Roundup ready canola (bushel/acre). 2004.: 

Melfort: Yield of Roundup ready canola (bushel/acre). 2004. 2002 Odyssey: p=NS 2003 Group 2 = NS No interaction

Lethbridge: Yield of Roundup ready canola (bushel/acre). 2004.: 

Lethbridge: Yield of Roundup ready canola (bushel/acre). 2004. 2002 Odyssey: p=0.08 2003 Group 2 = NS No interaction

Saskatoon: Yield of Roundup ready canola (bushel/acre). 2004.: 

Saskatoon: Yield of Roundup ready canola (bushel/acre). 2004. 2002 Odyssey: p=NS 2003 Group 2 = NS No interaction

Slide50: 

Scott 2005 Check / Check Odyssey / Check Odyssey / Assert Odyssey / Sundance

Pea-Wheat-Canola sequenceCanola phaseSummary: 

Pea-Wheat-Canola sequence Canola phase Summary Fairview (6-7% OM) – very dry in 2003, similar early injury ratings as Scott and Vanscoy. High rainfall in July and August 2004 – crop recovered, no clear yield reduction trends. Yield reduction from repeated applications most evident at Scott and Vanscoy (dry 2002-03).

Experiment 1: 

Experiment 1 Crop Sequence Year 1 – Wheat Year 2 – Field Pea Year 3 – Wheat/ barley Year 4 – RR Canola Herbicide treatments 2002 – Non-Group 2 Check, Assert, Refine Extra, Sundance, Spectrum, Frontline, Everest 2003 – Non-Group 2 Checks, Odyssey

Results on Field Peas Year 2 (2003): 

Results on Field Peas Year 2 (2003) No significant difference in field pea plant number over all sites Minimal injury observed (andlt;5%) over 3 ratings at all locations (Combined data) No significant yield reduction in field peas in 2003 with the exception of Assert carryover at Scott evident (no additive effect with Odyssey) – Not registered.

Year 3(2004)Wheat and BarleyDoes Stacking Exist?: 

Year 3 (2004) Wheat and Barley Does Stacking Exist?

Scott: 2nd injury rating to barley. 2004. : 

Scott: 2nd injury rating to barley. 2004.

Scott: 3rd injury rating to barley. 2004. : 

Scott: 3rd injury rating to barley. 2004.

Scott: Yield of barley (bus/acre) 2004. : 

Scott: Yield of barley (bus/acre) 2004. Year 1 Group 2: p=0.23 Year 2 Group 2: p=0.04 No interaction Odyssey andgt; No Odyssey

Vanscoy: 1st injury rating to barley. 2004. : 

Vanscoy: 1st injury rating to barley. 2004.

Vanscoy: 2nd injury rating to barley. 2004. : 

Vanscoy: 2nd injury rating to barley. 2004.

Slide60: 

Vanscoy barley 2004 – REP 3

Vanscoy: Yield of barley (bus/acre) 2004. : 

Vanscoy: Yield of barley (bus/acre) 2004. * *

Vanscoy: Yield of wheat (bus/acre) 2004. : 

Vanscoy: Yield of wheat (bus/acre) 2004. Year 1 herbicide p=0.71 Year 2 herbicide p =0.004 Odyssey andgt; No Odyssey No interaction

Conclusions – Experiment 1: 

Conclusions – Experiment 1 Two out of 8 site-years revealed some indication of stacking (Assert-Odyssey andamp; Sundance-Odyssey) injury in barley. Yield loss in barley occurred at 1 site. Dry sites (Scott and Vanscoy) most responsive.

Slide64: 

Summarize: 

Summarize In some situations: A residual Group 2 herbicide can predispose the following crop to injury from a post-emergence Group 2 herbicide; Back to back Group 2 residual herbicides can result in additive or synergistic phytotoxicity to rotational crops: Risk is higher in drought conditions. Additive or synergistic crop injury does not always cause crop yield loss.

Bottom Line: 

Bottom Line While 'stacking' can occur, the issue is preventable Good product stewardship; Follow herbicide rotation recommendations suggested for managing herbicide resistance; Avoid sequences of Odyssey-Assert and Odyssey-Sundance in back-to-back applications.

Slide67: 

Acknowledgements: Technical help of Glen Forster, Herb Schell, Lyle Boswall, Gerry Stuber, Lisa Ratz, Bill Sullivan and Three Links AgResearch is much appreciated. Matching Funds provided by Agriculture and Agri-Food Canada Matching Investment Initiative.