Weed Management - Peter Sikkema - 4

Weed Management in Corn, Soybean & Wheat

Questions from Ontario Farmers

1

Swanton, UG

Ragweed in soybean Giant ragweed in corn Canada fleabane in wheat

Atriplex in corn Wild Carrot in corn

Peter H. Sikkema

Eastern Ontario Crops

Conference

February 14, 2017

Sikkema, UG Sikkema, UG Sikkema, UG

Sikkema, UG Sikkema, UG

Question # 1

Peter, ever since I started growing RR corn and

soybean, field horsetail is an increasing problem on

my farm.

How can I control it?

2Sikkema, UG Sikkema, UG

Field Horsetail Control in Corn

3

Postemergence

37

50

66

57

73

0 20 40 60 80 100

Ultim

Broadstrike

MCPA

Ultim + Broadstrike

Ultim + MCPA

Broadstrike + MCPA

Ultim + Broadstrike +MCPA

Weed Control (%)

Summary of 6 experimentsSikkema, UG

Field Horsetail Control in Corn

4

Postemergence

37

50

66

57

73

83

85

0 20 40 60 80 100

Ultim

Broadstrike

MCPA

Ultim + Broadstrike

Ultim + MCPA

Broadstrike + MCPA

Ultim + Broadstrike +MCPA

Weed Control (%)


Field Horsetail – Corn – POST



Weedy Check Broadstrike (50%)

MCPA (66%) Broadstrike + MCPA (83%)

Field Horsetail

Ultim + Broadstrike + MCPA

June 11

Litwin, UG

Litwin, UGLitwin, UG

June 24

What about MCPA injury in corn?



Brace-root malformation Lodging or goose-necking

Brittle snap Onion leafing

MCPA Tolerance in Corn

8

It is pretty safe applied at V2 (4 leaf stage)

237

239

237

235

0 50 100 150 200 250

Control

1/4 X

1/2 X

1X

Yield (bu/ac)

V2 (4 leaf stage)Sikkema, UG

MCPA Tolerance in Corn

9

44 bu/ac yield loss when applied late!

237

220

207

193

0 50 100 150 200 250

Control

1/4 X

1/2 X

1X

Yield (bu/ac)

V6 (8 leaf stage)Sikkema, UG

Field Horsetail in Soybean

10

Roundup + Broadstrike + Dual applied PP

Applied: June 8

July 11

Litwin, UG

Field Horsetail Control in Soybean

11

Roundup + Broadstrike + Dual applied PP

97

95

91

89

84

0 20 40 60 80 100

Site 1

Site 2

Site 3

Site 4

Site 5

Site 6

Weed Control (%)

Field horstail control in soybeanSikkema, UG

Field Horsetail Control in Soybean

12

Roundup + Broadstrike + Dual

97

95

91

89

84

46

0 20 40 60 80 100

Site 1

Site 2

Site 3

Site 4

Site 5

Site 6

Weed Control (%)

Site 1 Site 2 Site 3 Site 4 Site 5 Site 6Sikkema, UG

Field Horsetail in

Soybean

13


Applied: June 8

October 15

Litwin, UG

Litwin, UGLitwin, UG

July 11

Field Horsetail

14


One month after application After harvest

Litwin, UG Litwin, UG

Field Horsetail in Wheat

MCPA is the product of choice15


Question # 1

Peter, ever since I started growing RR corn and soybean, field

horsetail is an increasing problem on my farm.


Answer

1. Corn: Broadstrike + MCPA

a. Apply early POST

b. Only spray the patches (can cause crop injury)

2. Soybean: Roundup + Dual + Broadstrike applied PP

3. Wheat: MCPA applied POST

16

Question # 2

17

Peter, ever since I started growing RR corn and soybean,

yellow nutsedge is an increasing problem on my farm.


Sikkema, UG Tardif, UG

Yellow Nutsedge Control in Corn

18

Swanton, UG

Postemergence

55

0 20 40 60 80 100

Basagran

Permit (1/2X)

Permit (Low)

Permit (High)

Permit (2X)

Yellow Nutsedge Control (%) – 8 WAA


Yellow Nutsedge Control in Corn

19

Swanton, UG

Postemergence

55

82

90

93

95

0 20 40 60 80 100

Basagran

Permit (1/2X)

Permit (Low)

Permit (High)

Permit (2X)

Yellow Nutsedge Control (%) – 8 WAA


Permit provides excellent control of

yellow nutsedge POST in corn

Control


Permit (low Rate)

Classic is excellent for the control of

yellow nutsedge POST in soybean

21Roundup + Classic Roundup

Tardif, UG

Question # 2

Peter, ever since I started growing RR corn and

soybean, yellow nutsedge is an increasing problem

on my farm.


Answer

1. Corn: Permit (POST)

2. Soybean: Classic (POST)

22

Question # 3

Peter, ever since I started growing RR corn and soybean, wild carrot is an increasing problem on my

farm. How can I control it?

23


Wild carrot in wheat Wild carrot in soybean

Wild Carrot

24

Corn – Soil Applied Herbicides

40

39

68

62

64

62

0 20 40 60 80 100

Atrazine

Banvel

Marksman

Converge+Atrazine

Callisto+Atrazine

Integrity

Weed Control (%)


Wild Carrot

25

Corn – Postemergence Herbicides50

37

69

47

56

59

46

74

0 20 40 60 80 100

Atrazine

Banvel

Distinct

Marksman

Pardner + Atrazine

PeakPlus

Callisto + Atrazine

Impact + Atrazine

Roundup

Weed Control (%)


Wild Carrot

26

Corn – Postemergence Herbicides50

37

69

47

56

99

59

46

74

0 20 40 60 80 100

Atrazine

Banvel

Distinct

Marksman

Pardner + Atrazine

Peak + Banvel

Callisto + Atrazine

Impact + Atrazine

Roundup

Weed Control (%)


Wild Carrot

27

Sikkema, UG

Sikkema, UG

Sikkema, UG

Check

Banvel (69%)

Peak + Banvel (99%)

Wild Carrot

28

Soybean – Soil Applied Herbicides

45

37

61

58

47

71

78

51

0 20 40 60 80 100

Roundup

Lorox

Sencor

FirstRate

Boundary

Broadstrike

Pursuit

Conquest

Weed Control (%)


Wild carrot control in soybean

29

Roundup + Dual + Broadstrike


A couple of weeks after application A couple of months after application

Wild Carrot

30

Soybean – Postemergence Herbicides

6

8

27

13

79

52

56

48

33

0 20 40 60 80 100

Blazer

Reflex

Basagran

Pinnacle

Classic

FirstRate

Pursuit

Clean Sweep

Roundup

Weed Control (%)


Wild carrot control in soybean with Classic

31


Classic (79%) Classic (79%)

Wild Carrot

32

Soybean – Sequential Herbicides

98

99

0 20 40 60 80 100

Broadstrike(PP); Classic

(POST)

Pursuit (PP);Classic (POST)

Weed Control (%)


Wild Carrot

33

Winter Wheat – Postemergence Herbicides23

40

35

46

73

26

76

46

51

88

0 20 40 60 80 100

2,4-D

MCPA

Target

Estaprop

Lontrel

Buctril M

Refine M

Trophy

Infinity

Peak + Pardner

Weed Control (%)


Wild Carrot

Sikkema, UG

Sikkema, UG

Sikkema, UG

Check

Refine M (76%)

Peak + Pardner (88%)

Question # 3

Ever since I started growing RR corn and soybean, wild carrot

is an increasing problem on my farm.


Answer

1. Corn: Peak applied POST

2. Soybean:

a. Broadstrike or Pursuit applied PP

b. Classic applied POST

c. Sequential of Broadstrike or Pursuit applied PP

followed by Classic POST

3. Wheat: Peak + Pardner or Refine M

35

Question # 4

Swanton, UG

Roundup Ready 2 Xtend soybean are going to be grown for the first time in 2017.

What do you think?

What is RR2 Xtend soybean?

1. RR2 Xtend soybean

a. Same as RR2Y soybean plus…

i. Resistance to dicamba

b. Resistance to dicamba is provided by…

i. Dicamba monooxygenase (DMO)

ii. DMO rapidly metabolizes dicamba before

it can buildup to toxic levels

37

What is RR2 Xtend soybean?

2. The DNA that codes for the DMO enzyme was obtained

from a microorganism (Pseudomonas maltophilia) from a

storm water retention pond at the 25 year old dicamba

manufacturing plant near Beaumont, Texas

3. Decreases sensitivity of RR2 Xtend soybean to dicamba

by a factor of 5000

38

Benefits of RR2 Xtend Soybean

1. Improved control of …

a. Annual broadleaf weeds

i. Wild buckwheat

b. Perennial broadleaf weeds

i. Field bindweed

c. Glyphosate resistant weeds

i. Giant ragweed

ii. Canada fleabane

39

40

Glyphosate Resistant Giant Ragweed

Excellent control of GR giant ragweed with dicamba in RR2

Xtend Soybean

Vink, UG Vink, UG

Roundup Roundup + dicamba


41

32

0 20 40 60 80 100

Roundup (PP); Roundup(POST)

Rdup (PP); Rdup + Banvel300 (POST)

Rdup + Banvel 300 (PP);Roundup (POST)

Rdup + Banvel 300 (PP);Rdup + Banvel 300 (POST)


GR Canada fleabane control (%) – 8 WAA

Glyphosate Resistant Canada Fleabane


Byker, UG

42

32

83

87

0 20 40 60 80 100









Byker, UG

43

32

83

87

95

0 20 40 60 80 100









Byker, UG

44

32

83

87

95

97

0 20 40 60 80 100









Byker, UG

45

Roundup PP; Roundup POST Roundup + Dicamba 600 (PP); Roundup (POST)




Excellent control of GR Canada fleabane with dicamba in

RR2 Xtend Soybean

Question # 4

Swanton, UG

Roundup Ready 2 Xtend soybean are going to be grown for the fist time in 2017.

What do you think?

Answer

I think this new technology will address some the weed control challenges in soybean in Ontario, BUT

Applicators will have to be very careful to avoid off-site injury

Question # 5

Swanton, UG

Roundup Ready 2 Xtend soybean are going to be grown for the first time in 2017.

Are you concerned about off-site movement?

YES

Off-site movement could be due to …

Drift

Volatilization

Temperature Inversion

Dicamba – Off-site Movement

Swanton, UG

RR2 Xtend Soybean Field



Swanton, UG

1. Spray date – June 29 at 12:30 pm

2. Wind speed – medium from NW

3. Soybean growth stage at application – V2

4. Sprayer

a. Application speed – 8 mph

b. Water volume – 15 gal/acre

c. Spray pressure - 30-40 psi

d. Boom height – 18 inches

e. Boom length – 100 feet

f. Nozzles – Hypro ultra low drift nozzles 120o, Red, 20 inch spacing

5. Herbicides

a. Xtendimax – 0.7 L/ac (612 g/ha)

b. Roundup (1 l/ac)

c. Classic (14 g/ac)

Summary


Swanton, UG

RR2 Xtend Soybean Field

Sikkema, UG

RR2Y Soybean Field

Sikkema, UG

Sikkema, UG


Swanton, UG

Injury symptoms in RR Soybean 1 m from source of dicamba



Swanton, UG



Question # 5

Swanton, UG

Roundup Ready Xtend soybean are going to be grown for the fist time in 2017.

Are you concerned about off-site movement?

Answer

I am very concerned

Soybean yield losses of greater than 10 bu/ac have been documented.

Question # 6

Swanton, UG

Roundup Ready 2 Xtend soybean are going to be

grown for the first time in 2017.

How important will tank clean out be prior to

spraying regular RR2Y soybean?

Severe injury in RR2Y soybean due to

dicamba tank contamination

59

0

20

40

60

80

0.125 0.25 0.5 1 2.5 5 10

2-3 trifoliate First flower

Dicamba Tank Contamination (%)

Sikkema, UG

Soybean I

nju

ry -

% 7

DA

A

1/8 of 1% Tank Contamination

11% injury – 2-3 trifoliate

6% injury – first flower

Dicamba

Tank

Contamination

Control

Sikkema, UG

Dicamba

Tank

Contamination

Control 0.125%


Dicamba

Tank

Contamination

Control 0.125% 0.25%

0.5% 1.0%

2.5% 5% 10%




63

0

20

40

60

80

100

0.125 0.25 0.5 1 2.5 5 10

V2-3 (2-3 trifoliate) R1 (First flower)Sikkema, UG

Soybean y

ield

-%

of

check

Dicamba Tank Contamination (%)

Substantial yield loss in RR2Y soybean

due to dicamba tank contamination1/8 of 1% Tank Contamination

7% yield loss – 2-3 trifoliate

10% yield loss – first flower

Question # 6

Swanton, UG

Roundup Ready Xtend soybean are going to be

grown for the fist time in 2017.

How important will tank clean out be prior to

spraying regular RR soybean?

Answer

Extremely important!

Question # 7

Peter, I had planned to spray my corn before the

weeds were 10 cm (4 inches) in height but we

have had three rain events and the weeds are now

20 cm (8 inches) tall.

Will there be a yield loss?

65

Corn yield decreases as weed size

increases at time of application

66

203

0

50

100

150

200

250

Weed Free 10 cm 20 cm 30 cm

Weed size at the time of herbicide application

Average of 5 experiments

Yie

ld (

bu/a

c)

Nurse, AAFC

Sikkema, UG

67



203 195

0

50

100

150

200

250

300



Average of 5 experimentsNurse, AAFC

Sikkema, UG

Yie

ld (

bu/a

c)

8 bu/ac

Yield loss

2 bu/ac

loss

for every

2.5 cm in

weed

height



68

203 195181

0

50

100

150

200

250

300




Yie

ld (

bu/a

c)

Nurse, AAFC

Sikkema, UG

2 bu/ac

loss

for every

2.5 cm in

weed

height

3.5 bu/ac

loss

for every

2.5 cm in

weed

height

8 bu/ac

Yield loss

22 bu/ac

Yield loss



69

2 bu/ac

loss

for every

2.5 cm in

weed

height

3.5 bu/ac

loss

for every

2.5 cm in

weed

height

203 195181

159

0

50

100

150

200

250

300




Yie

ld (

bu/a

c)

Nurse, AAFC

Sikkema, UG

2 bu/ac

loss

for every

2.5 cm in

weed

height

3.5 bu/ac

loss

for every

2.5 cm in

weed

height

5.5 bu/ac

loss

for every

2.5 cm in

weed

height

8 bu/ac

Yield loss

22 bu/ac

Yield loss

44 bu/ac

Yield loss

Question # 7

Peter, I had planned to spray my corn before the weeds were

10 cm (4 inches) in height but we have had three rain events

and the weeds are now 20 cm (8 inches) tall.

Will there be a yield loss?

Answer

Most likely.

Corn is very sensitive to early weed competition. I think all

corn producers should consider a two-pass weed control

program of a PRE herbicide followed by a POST herbicide.

70

Question # 8

OK Peter, you convinced me that I should use a

PRE herbicide in my RR corn.

Does it matter which PRE herbicide I use?

71

Which soil applied herbicide should I

use?

Which one is the best?

72

Lots to choose from…

Primextra

Converge

Integrity

Lumax

Which soil applied herbicide should I use?

73

Depending on the weed spectrum, sometimes it does not matter*

0

20

40

60

80

100

Pigweed, Green Lamb's-quarters Lady's Thumb Barnyard Grass Foxtail, Green

Primextra Integrity Converge Lumax

Weed C

ontr

ol (%

) 4 W

AE

Nurse, AAFC

Gillard, UG

Sikkema, UG *Set up rates were used. Weed control ratings prior to Roundup applied POST


74

Depending on the weed spectrum, sometimes it does matter*

44

64

0

20

40

60

80

100

Velvetleaf Ragweed, Common


Weed C

ontr

ol (%

) 4 W

AE

Nurse, AAFC

Gillard, UG



75


44

6464

74

65

77

0

20

40

60

80

100



Weed C

ontr

ol (%

) 4 W

AE

Nurse, AAFC

Gillard, UG



76


44

6464

74

65

7776

83

0

20

40

60

80

100



Weed C

ontr

ol (%

) 4 W

AE

Nurse, AAFC

Gillard, UG



77

No difference in corn yield*

107 d

202 abc 204 abc 205 abc 210 ab 207 ab

0

50

100

150

200

250

Weedy Primextra Integrity Converge Lumax Weed-free

Corn Yield (bu/ac)

Corn

Yie

ld (

bu/a

c)

Nurse, AAFC

Gillard, UG

Sikkema, UG *Two-pass weed control – PRE residual fb Roundup POST

Question # 8

OK Peter, you convinced me that I should use a PRE residual

herbicide in my RR corn.

Does it matter which one I use?

Answer

1. Yes, it will depend on…

a. Weed control

i. Weed species composition and density

ii. Resistance management

b. Crop safety

i. Soil characteristics – texture, pH, OM, CEC

ii. Corn hybrid

c. Persistence – future crops in the rotation78

Question # 9

I applied a PRE herbicide in corn and it was perfectly clean

up to the 6-leaf stage (V4), however, the last time I scouted

the field, I noticed some weeds.

Will they reduce corn yield?

Is it worth it to apply a POST herbicide?

79Weed free to 2-leaf Weed free to 10-leaf


Experimental Design

80

Weedy check Weed free to 2-leaf Weed free to 4-leaf

Weed free to 6-leaf Weed free to 8-leaf Weed free to 10-leaf



End of season weed control improves

the longer the corn is kept weed free

81

61

82

9197 99

0

20

40

60

80

100

2 4 6 8 10

Corn leaf stage at last Roundup application

Average of 13 weed species in 11 experimentsNurse, AAFC

Sikkema, UG

Everman, MSU

Sprague, MSU

Weed C

ontr

ol (%

) –

42 D

AA

82

Keep corn weed-free until at least the

6-leaf stage

105

185198

206 207 206 204

0

50

100

150

200

250

Weedycheck

2 4 6 8 10 Weed freecheck

Corn leaf stage at last Roundup application

Average of 11 experimentsNurse, AAFC

Sikkema, UG

Everman, MSU

Sprague, MSU

Yie

ld (

bu

/ac)

19 bu/ac yield

decrease

6 bu/ac yield

decrease

0 bu/ac yield

decrease

83



Weedy (-99 bu/ac) WF to 2-leaf (-19 bu/ac) WF to 4-leaf (-6 bu/ac)

Weed free to 6-leaf Weed free to 8-leaf Weed free to 10-leaf

Keep corn weed-free until at least the 6-leaf stage

Question # 9

I applied a PRE herbicide in corn and it was perfectly

clean up to the 6-leaf stage (V4), however, the last

time I scouted the field, I noticed some weeds.

Will they reduce corn yield?

Is it worth it to apply a POST herbicide?

Answer

Probably not

84

Question # 10

Swanton, UG

Peter, I have always applied Roundup at 0.67 L/ac.

Am I doing the right thing?

You have to adjust the rate of Roundup

depending on weed species for 90% control

86

0.5 0.7 0.6

0

0.5

1

1.5

2

2.5

Green foxtail Barnyard grass Redroot pigweed Lamb's-quarters Commonragweed

Roundup

Rate

(L/a

c)

Roundup Weathermax Rate (L/ac)Nurse, AAFC

Sikkema, UG

Weed Height = 30 cm tall

87

0.5 0.7 0.6

1.3

0

0.5

1

1.5

2

2.5

Green foxtail Barnyard grass Redroot pigweed Lamb's-quarters Commonragweed

Roundup

Rate

(L/a

c)

Roundup Weathermax Rate (L/ac)

Nurse, AAFC

Sikkema, UG




88

0.5 0.7 0.6

1.3

2.4

0

0.5

1

1.5

2

2.5

Green Foxtail Barnyard grass Redroot pigweed Lamb's-quarters Commonragweed

Roundup

Rate

(L/a

c)

Roundup Weathermax Rate (L/ac)

Nurse, AAFC

Sikkema, UG




5X the rate of Roundup

89


depending on weed height for 90% control

0.07

0.22

0.50

0.00

0.50

1.00

1.50

10 20 30

Roundup

Rate

(L/a

c)

Green foxtail

Weed Height (cm)

Nurse, AAFC

Sikkema, UG


90


depending on weed height for 90% control

0.46

0.67

1.28

0.00

0.50

1.00

1.50

10 20 30

Roundup

Rate

(L/a

c)

Lamb's-quarters

Weed Height (cm)

Nurse, AAFC

Sikkema, UG


Question # 10

1. The rate of Roundup needs to be adjusted

depending on weed species. In general, with

Roundup, the weeds that are easiest to most

difficult control are…

a. Easiest – Annual and perennial grasses

b. Intermediate – Annual broadleaf weeds

c. Most difficult – Perennial broadleaf weeds

i. There are species differences within each of

the above groups

Summary

Question # 10

2. Weed control decreases as weed size at the

time of application increases

a. Generally, the increase in weed size can be

overcome by increasing the rate of Roundup

Summary

Question # 10

Peter, I have always applied Roundup at 0.67 L/ac.

Am I doing the right thing?

Answer

Probably not

Question # 11

94

Swanton, UG

Peter, my corn is in the V5 stage and I noticed

some Canada fleabane escapes after my

POST application of Roundup. I have never

seen them on the farm before, so I assume

they are glyphosate resistant.

Is it OK to add some 2,4-D to my late in-crop

application of Roundup to control GR Canada

fleabane?

Phenoxies

1. Lodging or goose

necking caused by…

a. Heavy rain and high

winds

i. Saturated soils

b. Late application of

Roundup + 2,4-D

c. Sensitive hybrid

95

Corn Injury Symptoms

Tolerant Hybrid

Sensitive Hybrid - 25 bu/acre yield loss

Sensitive Hybrid

Sikkema, UG

2,4-D injury in corn



Brace-root malformation Lodging or goose-necking

Brittle snap Onion leafing

Can I add 2,4-D to Roundup for the

control of GR Canada fleabane?

97

Corn Injury (1 WAA)

0

5

0

5

10

15

20

25

Roundup 2,4-D Roundup + 2,4-D

1X

Sikkema, UG

Corn

Inju

ry (

%)

–1 W

AA

V1,3,5 application - Mean of 2 hybrids at 4 sites = 24 data points



98

Corn Injury (1 WAA)

0

5

19

0

5

10

15

20

25


1X

V1,3,5 application - Mean of 2 hybrids at 4 sites = 24 data points

Corn

Inju

ry (

%)

–1 W

AA

Sikkema, UG

14% synergistic

increase in injury



99

5-17% Synergistic

Increase in Injury248

233

0

50

100

150

200

250

300


1X

Corn

Yie

ld (

bu/a

c)

V1, V3, V5 application - Mean of 2 hybrids at 3 sites = 18 data pointsSikkema, UG

15 bu/ac

Yield loss



100

5-17% Synergistic

Increase in Injury248

233 225

0

50

100

150

200

250

300


1X

Corn

Yie

ld (

bu/a

c)

V1, V3, V5 application - Mean of 2 hybrids at 3 sites = 18 data pointsSikkema, UG

23 bu/ac

Yield loss

Synergistic

15 bu/ac

Yield loss

Question # 11

Peter, I noticed some Canada fleabane escapes in

my Roundup Ready Corn.

Is it OK to add some 2,4-D to my late in-crop

application of Roundup to control the GR Canada

fleabane?

Answer

No. There is potential for corn injury and yield loss.

It would be OK if you have Enlist corn.

101

Weed Management in Corn, Soybean & Wheat

Questions from Ontario Farmers

• Funding agencies

• Research technicians

• Graduate students

• Summer research assistants

102

Acknowledgements

Weed Management - Peter Sikkema - 4

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Transcript of Weed Management - Peter Sikkema - 4