Glyphosate Resistance And The Impact On Agriculture · 2009 2011 near Prinsburg, MN Crystal: 81%...

Glyphosate Resistance And The

Impact On Agriculture

Jeff StachlerExtension Agronomist – Sugarbeet / Weed Science

NDSU and U of MN12-13-12

Dr. Jeff Stachler

Presentation outline

1. Why should we care about weed resistance??

2. The situation in ND and MN

3. Defining high-level & low-level resistance

4. General solutions

Dr. Jeff Stachler

Why should we care about weed resistance?

• No new novel herbicide site / mechanism of action is expected for the next 5 to 10 years!

• Reduced profits if resistant biotypes selected

• Weed resistance, most importantly multiple resistance continues to increase

Dr. Jeff Stachler

Why should we care about weed resistance? – Lost profit

$12.00/A

Roundup PowerMAX

(32 / 22 / 22 fl oz/A )

$145/A

Ro-Neet (5.3 pt/A) [PPI] fbBetamix (12 / 16 / 24 fl oz/A) +

Nortron (4 fl oz/A) +Outlook (14 / 10 fl oz/A) +

Roundup PowerMAX(32 / 22 / 22 fl oz/A )

+ $133/A

Dr. Jeff Stachler

Why should we care about weed resistance?

2009 2011near Prinsburg, MN

Crystal: 81% growers reported Excellent weed control with glyphosate

SMBSC: 59% ExcellentSMBSC

CrystalCrystal: 90% growers reported Excellent weed control with glyphosate

SMBSC: 76% Excellent

Dr. Jeff Stachler

The Situation

Gly-R common ragweedGly-R giant ragweedGly-R waterhemp

Areas and counties of ND and MN havingconfirmed and suspected glyphosate-resistant weeds

2007

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

Gly-R common ragweedGly-R giant ragweedGly-R waterhemp

50 to 95% all fields have gly-R G. Rag.

30 to 60% all fields gly-RC. Rag.

5 to 90% all fieldsgly-R waterhemp

10 to 40% soybean fieldsgly-R C. Rag.

Areas and counties of ND and MN havingconfirmed and suspected glyphosate-resistant weeds

30 to 90% all fields have gly-R waterhemp

2010

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

25 to 40% soybean fields gly-R C. Rag.

Dr. Jeff Stachler

Waterhemp - Holloway, MN – 2010two glyphosate applications

Gly-R horseweed / marestailGly-R kochiaGly-R common ragweedGly-R giant ragweedGly-R waterhemp

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

Areas and counties of ND and MN havingconfirmed and suspected glyphosate-resistant weeds

2011 70 to 95% all fields gly-RC. Rag.

30 to 60% all fields gly-RC. Rag.

60 to 95% all fields have gly-R G. Rag.

70 to 95% all fields have gly-R waterhemp

5 to 95% all fieldsgly-R waterhemp

5 to 95% all fields gly-RG. Rag. & waterhemp

5 to 50% soybean fields gly-R C. Rag.

Dr. Jeff Stachler

Waterhemp - Moorhead, MN – 2011two glyphosate applications

Dr. Jeff Stachler

Waterhemp & common ragweed - SW Traill Co., ND - 2011

Waterhemp

Dr. Jeff Stachler

Common ragweed - E. of Nielsville, MN - 2011

Bettermanagement

ContinuousRR soybean

ContinuousRR soybean

Bettermanagement

Dr. Jeff Stachler

Glyphosate-resistant kochia – Stutsman and Pierce Co., ND – 2011 (least activity)

Stutsman Co., ND Population

Susceptible Check

UntreatedCheck

0.375 lb ae/ARndp 10.7 fl oz/A

6 lb ae/ARndp 1.3 gal/A

3 lb ae/ARndp 85 fl oz/A

1.5 lb ae/ARndp 43 fl oz/A

1.125 lb ae/ARndp 32 fl oz/A

0.75 lb ae/ARndp 21.3 fl oz/A

0.56 lb ae/ARndp 16 fl oz/A

Pierce Co., ND Population

Gly-R horseweed / marestailGly-R kochiaGly-R common ragweedGly-R giant ragweedGly-R waterhemp

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

Areas and counties of ND and MN havingconfirmed and suspected glyphosate-resistant weeds

2012

5 to 95% all fieldsgly-R waterhemp

5 to 95% all fields gly-RG. Rag. & waterhemp

15 to 90% soybean fields gly-R C. Rag.

5 to 60% all fields have gly-R kochia

Dr. Jeff Stachler

Glyphosate-resistant kochia - Richland County, ND - 2012

Photo from: Ingrid Kristjanson

Dr. Jeff Stachler

Glyphosate-resistant kochia - McIntosh County, ND – 2012Also present: Horseweed (marestail), and Lambsquarters

= kochia = horseweed

Dr. Jeff Stachler

Locations of Run 1 samples tested – 11-12

Dr. Jeff Stachler

2012 Glyphosate-R test results0.75 lb ae/A

Rndp 21.3 fl oz/A2.25 lb ae/A

Rndp 64 fl oz/A

Richland Co., ND Population

Benson Co., ND Population

Susceptible Check

R

S

Currently 29% of 38 samples have tested positive

Dr. Jeff Stachler

2012 Glyphosate-R test results0.75 lb ae/A

Rndp 21.3 fl oz/A2.25 lb ae/A

Rndp 64 fl oz/A

Logan Co., ND Population

Benson Co., ND Population

Susceptible Check

R

S

Dr. Jeff Stachler

Glyphosate-resistant horseweed in Cass County, ND

2011 - <1% of field

2012 - 60% of field + 2 other fields

Dr. Jeff Stachler

Additional herbicide resistance issues

1. Fluroxypyr-R kochia1. Present in 20 to 50% of fields in Central ND

Dr. Jeff Stachler

Dicamba and fluroxypyr-resistant kochia – Pierce Co., ND 2011 seed

Higher ground (no salt)

UntreatedCheck

Atrazine0.5 lb ai/A

Clarity8.0 fl oz/A 2.86 fl oz/A

Clarity4.0 fl oz/A

Salt spot

5.7 fl oz/A

11.4 fl oz/A

22.8fl oz/A

Starane Ultra

Counties of ND and MN havingconfirmed fluroxypyr (Starane)-resistant kochia

2011

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

100% (2/2) = R

Dr. Jeff Stachler

2012 Fluroxypyr-R test results0.12 lb ae/A (1.9 oz ae)Starane Ultra 5.5 fl oz/A

0.25 lb ae/A (4 oz ae)Starane Ultra 11.4 fl oz/A

Cavalier Co., ND Population

Benson Co., ND Population

Susceptible Population

R

S

Counties of ND and MN havingconfirmed fluroxypyr (Starane)-resistant kochia

2012

Black symbols: confirmed resistant cases; Blue: highly suspectedProvided by: Drs. Jeff Stachler, Jeff Gunsolus, Mike Christoffers, and Kirk Howatt

63% (12/19) = R

Dr. Jeff Stachler

Additional herbicide resistance issues

1. Fluroxypyr-R kochia ???1. Potentially present in 20 to 50% of fields in Central ND

2. PPO-R common ragweed and giant ragweed1. Likely present in Mahnomen Co., MN

Dr. Jeff Stachler

Conventional Soybean in Mahnomen County, MN - 2012Flexstar (0.75 pt/A) 2 times

Dr. Jeff Stachler

Additional herbicide resistance issues

1. Fluroxypyr-R kochia ???1. Potentially present in 20 to 50% of fields in Central ND

2. PPO-R common ragweed and giant ragweed1. Likely present in Mahnomen Co., MN

3. Bentazon-R biennial wormwood ??? (ND)4. Multiple herbicide resistance

1. PPO + ALS + glyphosate in waterhemp (MN & ND)2. ALS + PPO + triazine + glyphosate in waterhemp (MN)3. Fluroxypyr/dicamba/2,4-D + glyphosate in kochia (ND)4. PPO + ALS in common ragweed (ND)5. ACCase + ALS in wild oat and green foxtail (ND & MN)

5. Others ??

Dr. Jeff Stachler

Multiple resistance???Cobra applied near Holloway, MN

Dr. Jeff Stachler

Multiple-resistant waterhemp

Untreated

Flexstar+ MSO+ AMS

1 pt3 pt

UltraBlazer+ MSO+ AMS

Sharpen+ MSO+ AMS

Cadet+ MSO+ AMS

Resource+ MSO+ AMS

Cobra+ MSO+ AMS

4.5 pt 2 oz6 oz

0.9 oz2.7 oz

3 oz9 oz

12.5 oz

37.5 oz

1.5 pt

SusceptibleCheck

Holloway,MN

ResistantCheck

(IL)

Dr. Jeff Stachler

Multiple-resistant waterhemp

Flexstar GT 3.5+ MSO+ AMS

3.5 pt

Aatrex+ MSO+ AMS

Callisto+ MSO+ AMS

HarmonyGT+ MSO+ AMS

Callisto+ Aatrex+ MSO+ AMS

TouchdownHiTech+ R-11+ AMS

3 qt3 oz

9 oz0.38 oz 3 oz

+ 1pt19 oz

58 oz1 qt

10.5 pt9 oz+ 3 pt

SusceptibleCheck

Holloway,MN

ResistantCheck

(IL)

Dr. Jeff Stachler

Dr. Jeff Stachler

Untreated

Flexstar

+ FirstRateGlyphosate

+ Flexstar

+ FirstRate

Glyphosate

+ FirstRate

Glyphosate

+ Flexstar

OH

Progeny

Susceptible

1X 4X 1X 4X1X 4X1X 4X

Size at time of application

Dr. Jeff Stachler

Multiple-resistant kochia - 2012

Cavalier Co., ND Population

Benson Co., ND Population

Susceptible Population

0.75 lb ae/ARndp 21.3 fl oz/A

2.25 lb ae/ARndp 64 fl oz/A

0.12 lb ae/A (1.9 oz ae)Starane Ultra 5.5 fl oz/A 0.25 lb ae/A (4 oz ae)

Starane Ultra 11.4 fl oz/A

R

S

Dr. Jeff Stachler

Defining High-Level & Low-Level Resistance

Dr. Jeff Stachler

• High-Level Resistance = Survival at rates > 10 timesthe labeled rate

– Application parameters (coverage, environment, etc.) unlikely to affect control of species!!

– Usually minimal injury

– The correct rate usually does not matter when initiallyselecting

– Second applications usually do not reduce seed production!

– Usually single gene change of target site

– Examples = triazine, ALS, and ACCase

Types of Herbicide Resistance

Dr. Jeff Stachler

Types of Herbicide Resistance

• Low-Level Resistance = Survival at rates < 10 times the labeled rate

– Many different application parameters (coverage, environment, etc.) likely to affect control of species!!

– Significant injury always occurs initially & CAN kill small plants

– The correct rate DOES matter when initially selecting!!!

– Second applications USUALLY REDUCE numbers of plants & seed production!

– May be multiple or single gene changes in target site or other sites

– Examples = glyphosate, PPO, synthetic auxins, paraquat

Dr. Jeff Stachler

Take-home message about resistance vs. tolerance

• Resistance– A change in response in the weed populations to the

herbicide.– Resistant biotypes will increase over time.

• Tolerance– No change in response in the weed population to the

herbicide.– Tolerant species should increase more rapidly than

resistant biotypes.

Solutions

Dr. Jeff Stachler

Solutions to weed resistance

• Scout 5 to 14 days after EACH herbicide application.

• Observe individual plant responses!!

Response of a resistant waterhemp population

DeadInjuredNormal

Continuous response of common ragweed to glyphosate

Picture from Al Cattanach

Dr. Jeff Stachler

Dead (40%)

Nearly Dead (36%)

Intermediate (9%)

Best survivors (14%)

Resistant

Continuous response of a susceptible kochia population to glyphosate

Dr. Jeff Stachler

Continuous response of kochia to glyphosate

Dr. Jeff Stachler

Continuous response of kochia to glyphosate

Website address for video “Scouting for Glyphosate Resistance”:

http://www.ag.ndsu.edu/weeds/herbicide-resistant-weeds

Solutions - Understand Impact of ONE Weed

Dr. Jeff Stachler

Single waterhemp plant in 2011 (Clay County, MN)actual seed number per plant = 142,000

Scenario: seed number on 1 plant in 1 acre =100,000 seeds

Dr. Jeff Stachler

Scenario

• If 25% (40% is possible) of seeds emerge next season (2012)

• Only 10% of emerged plants are resistant• Same herbicide is applied as previous year• How many plants may be present in 1 acre at

the end of the season (2012)?

Dr. Jeff Stachler

2,500 plants/A – 1 year later (2012)

Dr. Jeff Stachler

6,250,000 plants/A!! - 2 years later (2013)

Field perimeter management (2010)

Dr. Jeff Stachler

Ramifications of not managing field perimeter (2011)

Dr. Jeff Stachler

Ramifications of not managing field perimeter (2012)

Dr. Jeff Stachler

Management of weeds along crop edges

Future problem! The Goal!

Solution – Practice ZERO TOLERANCE (no seed rain)

• Hand-weeding– Remove / destroy surviving plants by hand from a

field, especially when there are just a few!– There in no better way to STOP the increase of

resistant biotypes.

• Or row cultivate and hand-weed

Single plant Small patch

Dr. Jeff Stachler

Solution – Practicing ZERO TOLERANCE (no seed rain)

• 52% of AR cotton hand-weeded in 2011– Average cost = $29.43/A (beets = $21.00/A)– Proactive hand-weeding - $4-5/A

• 2010 hand-weeding – 110 hours/50 acres ($22/A)• 2011 hand-weeding – 5 hours/50 acres ($1/A)

ND Grower Website – Stewardship Practices:Weed Control – We strive to manage weeds to provide nearly 100% weed control in all crops and even those on the perimeter. We’re tough on weeds, but not on the land.

IL Land Lease:Weed Control – The Landlord and Tenant agree that control of weeds is an extremely important aspect of crop production. … If herbicidal treatment fails to control weeds and subsequent retreatment(s) also fail, then Tenant shall be solely responsible to use mechanical methods to control weeds including but not limiting to hand hoeing, hand pulling, and cultivation. Tenant … that will minimize the risk of for resistance weeds.

Dr. Jeff Stachler

Solution – Practicing Zero Tolerance

• 1 hr/50 A = 0.02 hr/A

• 0.02 hr/A X 5000 A = 100 hrs

• 100 hrs 10 hrs/day = 10 days

• 100 hrs X $10/hr = $1,000

• Vs $133/A X 5000 A = $665,000• Vs $20/A X 5000 A = $100,000

Dr. Jeff Stachler

Solution – Respond quickly!

Dr. Jeff Stachler

Solution – Understand impact of weed seed movement

• Means of dispersal:– Water (especially for waterhemp)– Machinery– Wind– Humans– Animals / birds

MPR Photo/Ann Arbor Miller

Dr. Jeff Stachler

Movement of waterhemp seeds by 2011 flood

To McLeod, ND15 mi. upstream

Direction of water movement

Dr. Jeff Stachler

Solutions

• Diversify weed management– Greater crop rotation– Start clean!– Use PRE herbicides in ALL crops– Rotate herbicide mechanisms of action– Tank-mix PRE and POST herbicides– Maximize herbicide activity

• Apply POST herbicides to small (< 3” weeds)• Optimize coverage• Use best adjuvant(s) and at highest rate

– Maximize cultural practices• Maximize quick crop canopy closure

Dr. Jeff Stachler

Control of glyphosate-R common ragweed – Mayville – 9-25

Herbicide Program RR Soy LL SoyRoundup / Liberty (2 times) 58 96Roundup / Liberty + Flexstar/Cobra/Cadet fb Rndp / Lib 73 (93/34) 98Roundup / Liberty + Outlook + Cobra fb Rndp / Lib 68 95PRE*** fb Roundup / Liberty (2 times) 78 99PRE** fb Roundup / Liberty + Flexstar fb Rndp / Lib 95 99PRE* fb Roundup / Liberty + Cobra + Outlk/Wrrnt fb Lib 99 99

*** 1. Boundary (1.8 pt/A) {59%}2. Prefix (1.75 pt/A) {69%}3. Valor (2.5 oz/A) + Dimetric (5.33 oz/A)

{76%}4. Fierce (3.0 oz/A) {44%}5. Sharpen (1 fl oz/A) + Zidua (2.5 oz/A)

{67%}6. Verdict (5 fl oz/A) + Zidua (2.5 oz/A)

{68%}

** 1. Boundary (1.8 pt/A)2. Verdict (5 fl oz/A) + Zidua (2.5 oz/A)

*1. Verdict (5 fl oz/A) + Zidua (2.5 oz/A)

Dr. Jeff Stachler

Yield of RR/LL soybean - Mayville

Herbicide Program RR Soy LL Soy% of Roundup alone

Roundup / Liberty (2 times) 100(8.1 bu/A)

122

Roundup / Liberty + Flexstar/Cobra/Cadet fb Rndp / Lib 104 122Roundup / Liberty + Outlook + Cobra fb Rndp / Lib 99 122PRE fb Roundup / Liberty (2 times) 133 133PRE fb Roundup / Liberty + Flexstar fb Rndp / Lib 146 165PRE fb Roundup / Liberty + Cobra + Outlk/Wrrnt fb Lib 135 123

Dr. Jeff Stachler

Herbicide, adjuvant, app., & seed costs - Mayville

Herbicide Program RR Soy LL Soy$ (% of Glyphosate alone)*

Roundup / Liberty (2 times) 88 (100%-$25)

95 (174)

Roundup / Liberty + Flexstar/Cobra/Cadet 106 (46) 108 (122)Roundup / Liberty + Outlook + Cobra fb Rndp / Lib 114 (-8) 118 (82)PRE fb Roundup / Liberty (2 times) 112 (157) 119 (129)PRE fb Roundup / Liberty + Flexstar 125 (161) 134 (214)PRE fb Roundup / Liberty + Cobra + Outlk/Wrrnt fb Lib 143 (38) 150 (-40)

App. Fee = $5.00/A/app.Seed costs = $60.84 (RR) & $51.81 (LL)

Soybean price = $14.00

Cost (Profit)*

Dr. Jeff Stachler

Final reminders

• You have a choice!–Delay resistance OR Ignore it

Final reminders - Leave a Legacy!

• The future success of your farming operation depends upon the weed control practices you choose today!

• Glyphosate is the most effective herbicide ever discovered, so let’s work together to preserve it’s effectiveness! THE Goal!

Dr. Jeff Stachler

• Thank You!

• ANY questions?

• Contact information– jeff.stachler@ndsu.edu– 701-231-8131 (Office)– 218-790-8131 (Cell)

• Resources– http://www.ag.ndsu.edu/weeds/– http://www.sbreb.org/