Living and Learning with Herbicide Resistant Weeds Eric P. Prostko - - PowerPoint PPT Presentation

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Living and Learning with Herbicide Resistant Weeds Eric P. Prostko - - PowerPoint PPT Presentation

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Living and Learning with Herbicide Resistant Weeds Eric P. Prostko and A. Stanley Culpepper Extension Weed Specialists Department of Crop & Soil Sciences UGA Weed Science Team Supporting Cast & Crew UGA Faculty Technical

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SLIDE 1

Living and Learning with Herbicide Resistant Weeds

Eric P. Prostko and A. Stanley Culpepper Extension Weed Specialists Department of Crop & Soil Sciences

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SLIDE 2

UGA Weed Science Team

Supporting Cast & Crew

  • UGA Faculty

– Tim Grey (Tifton) – Bill Vencill (Athens) – Mark Czarnota (Griffin) – Tim Murphy (Griffin)

  • USDA-ARS

– Carroll Johnson – Ted Webster

  • Post-Doc’s

– Lynn Sosnoskie

  • Valdosta State Univ.

– Richard Carter

  • Technical Support

– Charlie Hilton – Amy Davis – Jesse Parker – Kevin Baldree

  • Administrative

– Dena Watson

  • Graduate Students

– Rebekah Wallace – Trey Cutts

  • Student Workers

– Too many to mention but – Very valuable to program

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SLIDE 3

Palmer Amaranth in Georgia

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SLIDE 4

Do what must be done?

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SLIDE 5

Why Palmer Amaranth (Amaranthus palmeri)?

  • 38 species of Amaranthus in

U.S.

  • 27 species found in SE
  • dioacious
  • grows faster than other

pigweeds (1-2” per day!!)

  • more competitive than other

pigweeds

  • prolific seed producer
  • seed to seed 9-12 WAE
  • 2 generations/year
  • herbicide tolerance

SWSS Weed ID Guide

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SLIDE 6

Herbicide Resistance Concerns in Georgia

  • glyphosate
  • ALS herbicides
  • Atrazine
  • Multiple resistance

– Glyphosate + ALS

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SLIDE 7

Georgia counties confirmed to be infested with glyphosate-resistant Palmer amaranth.

2004 – 1 county 2005 – 2 counties 2006 – 7 counties 2007 – 10 counties 2008 – 6 so far 1-28-09

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SLIDE 8

GA Confirmed ALS-Resistant Palmer Sites

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SLIDE 9

2008 Triazine Resistance Survey

Macon County

4/20 sites resistant to 10X rate (4,5,15,20) 6/20 sites took 5 qts/A to kill (3,6,8,14,17,19)

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SLIDE 10

Site 5 – Atrazine Resistance Survey

0.1 1 5 10 Atrazine (qts/ A)

*Not resistant to Evik (ametryn) or Direx (diuron)

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SLIDE 11

How did this happen to us?????

  • Economics drive farmer decisions
  • No real long-term weed mgt.

planning

  • Farm logistics
  • Overuse of glyphosate
  • Overuse of Staple and Cadre
  • Reduced herbicides rates
  • Reduced tillage
  • Reduction in use of residuals
  • Dryland production systems
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SLIDE 12

Palmer Amaranth Biology

  • How many seed?
  • How long can the seed

survive in the soil?

  • Where does most of the

germination occur?

  • Pollen Drift
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SLIDE 13

# of seeds

Palmer amaranth seed production in Georgia from a single female plant when competing with cotton for the season

100,000 200,000 300,000 400,000 500,000

450,000 Macon Co. 2006

*1,000,000 seed/plant (Keeley et al. 1987. Weed Science 35:199-204) California

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SLIDE 14

R-Palmer amaranth seed longevity

Length of burial

0 mon. 3 mon. 6 mon. 9 mon.

Percent (%) viable

40 50 60 70 80 90 100 0.5" 1" 4" 16"

Source: Dr. Lynn Sosnoskie - UGA

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SLIDE 15

Influence of burial depth on Palmer amaranth emergence in Georgia

Depth of burial (inches)

0.5" 1" 4" 16"

Percent (%) emergence

10 20 30 40 50 S-Palmer amaranth R-Palmer amaranth

Source: Dr. Lynn Sosnoskie - UGA

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SLIDE 16

Herbicide Resistant Weeds

Pollen Drift

  • Off-site movement (wind,

gravity, insects, man, animal)

  • f resistance trait through

pollen

  • Pollen from resistant male

fertilizes susceptible female to produce resistant progeny (seed)

  • UGA researchers have

documented GR-trait movement of at least 960’ (Palmer amaranth). Palmer Amaranth Pollen Source: Dr. Lynn Sosnoskie

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SLIDE 17

In-field Palmer amaranth pollen movement

Distance (m) from source of resistance 1 5 10 25 50 75 100 150 200 250 300 % Resistant offspring per parent plant 20 40 60 80 100 2006 2007

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Cultural Practices

  • Deep tillage
  • Extreme cover crops
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SLIDE 19

No Deep Tillage Deep Turn

No Herbicide Treatment

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Palmer amaranth seedling density as influenced by tillage.

Treatments

No-Break Break

AMAPA density/m2 to a depth of 5 cm

2000 4000 6000 8000 10000 12000 14000

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SLIDE 21
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SLIDE 22

Dryland Systems

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Irrigation in Georgia

10 20 30 40 50 60 70 1970 1975 1977 1980 1986 1992 1995 2000 2004 2008 Y ear A cres (%) Peanut Soybean C

  • tton

C

  • rn

Source: Kerry Harrison, UGA Extension Engineer

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SLIDE 24

May-June 2008 Rainfall Distribution in Midville

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

May

Crops planted from May 21-June 21 did not receive enough rainfall to activate herbicides (0.26” total). June Rainfall = 0.62” which occurred as follows:12 (0.08”); 22 (0.36”); 26 (0.08”); 29 (0.10”)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

June

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SLIDE 25

If residual herbicides are not activated on a timely basis with a reliable water source, pigweed control will be very difficult, maybe even impossible!

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Dryland Systems

  • Growers need to think

about mechanical herbicide incorporation

  • Will help but not a

guarantee

  • Success will depend

upon……

– operator – Implement – Soil conditions

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SLIDE 27

Chemical Control Options

  • Valor (flumioxazin)
  • Reflex (fomesafen)
  • Dual Magnum (S-metolachlor)
  • Atrazine
  • Liberty-Link (glufosinate)
  • Sencor products (metribuzin)
  • KIH-485
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SLIDE 28

Palmer Amaranth Control in Peanuts

Macon County, GA – 2007 (38 DAT)

NTC Valor SX 51WG @ 3 oz/A

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SLIDE 29

Palmer Amaranth Control in Peanuts

Macon County, GA – 2007 (38 DAT)

NTC Dual Magnum 7.62EC @ 1 pt/A

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SLIDE 30

NTC

Atrazine 4L @ 1 qt/A – PRE Atrazine 4L @ 1.5 qt/A – 30 DAP Peptoil @ 1% v/v – 30 DAP

Macon County – GR Palmer Amaranth June 24, 2008 – 60 DAP CN-01-08

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SLIDE 31

RR RR vs vs LL Corn LL Corn -

  • 2008

2008

Untreated

Roundup W-Max @ 22 oz/A Atrazine @ 1.5 qt/A Prowl H2O @ 2.1 pt/A (POST) Ignite 2.34 SL @ 23 oz/A Atrazine @ 1.5 qt/A Prowl H2O @ 2.1 pt/A AMS @ 3 lb/A (POST) CN-11-08 6/17/2008 81 DAP

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SLIDE 32

Metribuzin Products on Soybeans

  • Sencor
  • Boundary

– Dual Magnum + Sencor

  • Canopy

– Sencor + Classic

  • Read label
  • Know soil texture and

OM

  • Varieties
  • rotations
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SLIDE 33

GR-Pigweed Control in Soybeans - 2008

SB-06-08 Macon County 48 DAP

NTC

Canopy 75DG @ 6 oz/A + Prowl H2O 3.8ASC @ 2.1 pt/A (PRE)

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SLIDE 34

GR-Palmer Amaranth Control in Soybeans - 2007

SB-01-07 Macon Co. 76 DAP

NTC

Gramoxone Inteon @ 3 pt/A + Boundary @ 1.8 pt/A + NIS @ 0.25% v/v (7 DBP) Touchdown Total @ 1.5 pt/A (26 DAP)

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SLIDE 35

Soybean varieties screened in 2008 that had adequate tolerance to Boundary 6.5EC (2 pt/A), Canopy 75DG (5

  • z/A), and Sencor 75DG (6 oz/A).
  • Ag South AGS 568

Asgrow H7242

  • Asgrow 4903 RR/STS

Delta Pineland DP 5634

  • Delta Pineland DP 6568

Northrup King NKS 80P2

  • Northrup King NKS 76L9

Northrup King NKS 78G6

  • Pioneer 95Y40

Pioneer 95Y70

  • Pioneer 96M60

Pioneer 97M50

  • Southern States RT5951

Southern States RT4808

  • Vigoro V61N9

Vigoro V74N9

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SLIDE 36

GR-Pigweed Control in Soybeans – 2008 Macon County

20 40 60 80 100

V a l

  • r

E n v i v e R e f l e x P r e f i x C a n

  • p

y S e n c

  • r

K I H

  • 4

8 5 D u a l M a g n u m .

Herbicide Control (% ) . 13 DAT 29 D AT 47 D AT 91 D AT

90%

Valor @ 3 oz/A; Envive @ 3 oz/A; Reflex @ 1 pt/A; Prefix @ 2 pt/A; Canopy @ 6 oz/A; Sencor @ 8 oz/A KIH-485 @ 4.2 oz/A; Dual Magnum @ 1 pt/A

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SLIDE 37

KIH-485

  • Pyroxasulfone
  • Kumiai
  • Developed for corn and soybeans
  • PRE
  • Herbicide Family

– – Sulfonylioxazoline (?) Sulfonylioxazoline (?)

  • Herbicide Mode of Action (?)

– – plant growth inhibitor that affects apical meristem plant growth inhibitor that affects apical meristem and coleoptile development of plants after seed and coleoptile development of plants after seed germination germination

  • Low use rates
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GR-Palmer Amaranth Control in Soybeans with PRE’s (2008) - Macon Co.

NTC KIH-485 85WG @ 4.2 oz/A

SB-05-08 48 DAT

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SLIDE 39

Under Utilized Modes of Action

  • HPPD-inhibitors

– Mesiotrione (Callisto) – Tembotrione (Laudis) – Topramezone (Impact)

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SLIDE 40

Halex GT in Field Corn Halex GT in Field Corn -

  • 2008

2008

Untreated

CN CN-

  • 05

05-

  • 08

08 6/19/2008 6/19/2008 83 DAP 83 DAP

Halex GT 4.39L 4 pt/A + NIS (POST)

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SLIDE 41

Don’t forget!!! There are no steel resistant weeds!!!

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We are overusing the PPO inhibiting herbicides!!!!!!!!

  • Resistance has already

been reported in other areas!!!

  • Common waterhemp

– 2001 (Kansas) – 2002 (Illinois) – 2003 (Missouri)

  • Common ragweed

– 2005 (Delaware)

  • Wild poinsettia

– 2004 (Brazil)

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SLIDE 43

For More Weed Science Info: www.gaweed.com

eprostko@uga.edu 229-386-3328 (office) 229-392-1034 (cell)