2004 Crop Production Considerations

Todd VagtsISU Extension Crop Field Specialist

Todd Vagts

Talking Points

• Rotation changes?• Corn – Soybean Yield Comparisons

– Soybean Yield Plateau?

• Pest Considerations– Soybean– Corn

Todd Vagts

The Rotation Decision?

• Traditional Corn-Soybean• Corn-Corn-Soybean• Continuous Corn

• Problems and Considerations

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Why Corn-Bean Rotation

• Higher Yields (?)– Rotation Effect…

• Lower fertilizer costs (?)• Less pest problems (?)

– Weeds, insects, disease

• Less crop residue to manage• Farm program (?)

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Corn Yield - % of Corn-Soybean RotationIA Studies

75%

80%

85%

90%

95%

100%

105%

23-Yr Data Set Last 4-YR Data Set

Co

rn G

rain

Yie

ld%

of

Co

rn-S

oyb

ean

Ro

tati

on

Corn-Soybean

Corn (1st Yr)

Corn (2nd Yr)

Continuos Corn

-10% -7%

(1998-01)

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Corn Yield - % of Corn-Soybean RotationIA Studies

75%

80%

85%

90%

95%

100%

105%

23-Yr Data Set Last 4-YR Data Set

Co

rn G

rain

Yie

ld%

of

Co

rn-S

oyb

ean

Ro

tati

on

Corn-Soybean

Corn (1st Yr)

Corn (2nd Yr)

Continuos Corn

CS | C (1) | C (2) | CC CS | C (1) | C (2) | CC

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Corn Yield - % of Corn-Soybean RotationMN-WI Studies

0.8

0.85

0.9

0.95

1

1.05

Corn-Soybean

Corn (1st Yr) Corn (2nd Yr) ContinuosCorn

Co

rn G

rain

Yie

ld%

of

Co

rn-S

oyb

ean

Ro

tati

on

-9%

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Corn Yield - % of Corn-Soybean RotationMN-WI Studies

0.8

0.85

0.9

0.95

1

1.05

Corn-S

oybe

an

Corn (1

st Yr)

Corn (2

nd Y

r)

Continu

os C

orn

Co

rn G

rain

Yie

ld%

of

Co

rn-S

oyb

ean

Ro

tati

on

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2nd Year Corn

• Potential 7 to 10 percent yield reduction compared to 1st year corn

• Additional 2 to 4 percent yield reduction with 3 or more years of corn

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Soybean Yield - % of Soybean-Corn RotationIA Studies

60%

70%

80%

90%

100%

110%

120%

23-YR Last 4-YR

% o

f S

oyb

ean

-Co

rn R

ota

tio

n

So

ybea

n Y

ield

Soy-Corn

Soy-Corn-Corn

Continuous Soy

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Rotation Yield Gains and Losses

• 2nd Year Corn– 8% Yield reduction X (149 bu/A) = 11.9

bu• 11.9 bu/A X $2.48 = $28.56 (Disadvantage)

• Soybean following 2nd Year Corn– 6% Yield Increase X (43.9 bu/A) = 2.6 bu

• 2.6 bu/A X $6.04 = $15.70 (Advantage)

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Costs to Corn-on-Corn2nd year corn and 3rd year soybean

Corn Yield Reduction Soybean Yield Gain

-$28.56 + $15.70

= -$12.86

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Nutrient Requirements

Nutrient Balance Summary

Rotation N (lb/yr) P2O5 (lb/yr) K2O (lb/yr)Corn/Soybean 63 53 66Corn/Corn/Soybean 91 58 59Corn/Corn/Corn/Soybean 119 56 58Continuous Corn 169 58 46

Nutrient Balance Summary

Rotation N P2O5 K2OCorn/Soybean 0% 0% 0%Corn/Corn/Soybean 145% 108% 89%Corn/Corn/Corn/Soybean 190% 106% 87%Continuous Corn 270% 108% 70%

% of Corn/Soybean

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Nutrient Costs

Nutrient Balance Cost Summary

Rotation Cost/Yr % IncreaseCorn/Soybean $28 0%Corn/Corn/Soybean $34 120%Corn/Corn/Corn/Soybean $39 139%Continuous Corn $48 171%

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Costs to Corn-on-Corn2nd year corn and 3rd year soybean

Corn Yield Reduction Soybean Yield Gain Fertilizer Cost

-$28.56 + $15.70 + -$12.00 (2 years)

= -$24.86 (2 year)

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Yield and Rotation

• Yield benefit to rotation most evident in lower yield environments (25%)– Yield benefit declines under high yield

environments for both corn and soybean (15% or less)

• Corn-Soybean rotation maximizes corn yield but not soybean yield

– The Corn Soybean Rotation Effect, Joe Laurer Paul Porter and Ed Oplinger. University of Wisconsin.

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Calhoun County Soybean and Corn Yields

Comparison

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5-Year Average Soybean Yield

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5 Year Average Yield

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Year: 2001

County Acres Yield State Rank County Acres Yield State RankScott 82,000 53.6 1 Scott 106,000 173.6 1Benton 169,000 50.6 2 Cedar 138,000 172.7 2Sioux 194,000 50.5 3 Delaware 160,000 169.3 3Sac 150,000 48.0 16 Webster 186,000 154.3 20Crawford 159,000 47.9 18 Sac 153,000 152.7 25Cherokee 141,000 47.9 19 Ida 112,000 146.2 40Ida 108,000 47.6 22 Buena Vista 159,000 144.4 47Buena Vista 158,000 46.5 26 Calhoun 165,000 144.2 48Carroll 145,000 46.3 28 Carroll 160,000 142.7 54Calhoun 167,000 43.7 46 Greene 156,000 140.7 57Webster 184,000 43.4 50 Crawford 174,000 137.6 65Pocahontas 168,000 42.5 59 Pocahontas 169,000 135.3 69Greene 154,000 42.1 64

STATE 44.0 STATE 146.0

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Year: 2002

County Acres Yield State Rank County Acres Yield State RankCherokee 133,000 58.0 1 Scott 107,000 186.9 1Clayton 47,400 54.9 2 Cedar 143,500 184.7 2Dubuque 36,700 54.5 3 Tama 157,000 184.7 3Sac 140,000 54.4 4 Webster 183,500 177.1 21Ida 103,400 52.9 12 Calhoun 162,500 171.7 34Buena Vista 145,900 52.1 16 Sac 156,000 169.9 46Carroll 137,900 52.1 17 Crawford 175,000 168.1 48Calhoun 151,900 51.2 20 Greene 155,500 167.2 49Crawford 154,700 50.5 25 Ida 111,000 167.0 50Webster 173,500 50.0 28 Carroll 153,500 164.6 55Pocahontas 155,800 48.9 42 Buena Vista 158,000 160.8 61Greene 145,900 48.5 45 Pocahontas 168,500 160.2 62

State 48.0 State 165.0

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Greater Advantage to Corn“High corn yields relative to soybean yields”

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Yield Trends 1971 - 02Corn and Soybean Yield

y = 1.7036x + 91.609

y = 0.4552x + 31.0950

20

40

60

80

100

120

140

160

180

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

Bu

/Ac

re

Corn and Soybean Yield

y = 1.6628x + 96.186

y = 0.4602x + 31.5310

20

40

60

80

100

120

140

160

180

200

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

Bu

/Ac

re

Iowa Calhoun County

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Yield Trend - 1997 - 02

Corn and Soybean Yield

y = 3.8x + 134.53

y = -0.0857x + 45.9670

20

40

60

80

100

120

140

160

180

1997 1998 1999 2000 2001 2002

Bu

/Ac

re

Corn and Soybean Yield

y = 0.9171x + 139.77

y = 1.02x + 40.5130

20

40

60

80

100

120

140

160

1997 1998 1999 2000 2001 2002B

u/A

cre

Iowa Calhoun County

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Corn and Soybean Yield

y = 3.8x + 134.53

y = -0.0857x + 45.9670

20

40

60

80

100

120

140

160

180

1997 1998 1999 2000 2001 2002

Bu

/Ac

reCorn and Soybean Yield

y = 5.4857x + 101.13

y = 0.9571x + 36.5670

20

40

60

80

100

120

140

160

1987 1988 1989 1990 1991 1992

Bu

/Ac

re

Corn and Soybean Yield

y = 5.2286x + 95.533

y = 0.3857x + 36.233

0

20

40

60

80

100

120

140

1977 1978 1979 1980 1981 1982

Bu

/Ac

re

6-Year Yield Trends Iowa1997 – 021987 – 921977 - 82

Todd Vagts

Corn and Soybean Yield

y = 0.9171x + 139.77

y = 1.02x + 40.5130

20

40

60

80

100

120

140

160

1997 1998 1999 2000 2001 2002

Bu

/Ac

reCorn and Soybean Yield

y = -3.8629x + 143.05

y = -0.1886x + 42.1270

20

40

60

80

100

120

140

160

1987 1988 1989 1990 1991 1992

Bu

/Ac

re

Corn and Soybean Yield

y = 10.891x + 76.847

y = 0.7914x + 36.380

20

40

60

80

100

120

140

160

1977 1978 1979 1980 1981 1982

Bu

/Ac

re

6-Year Yield Trends Calhoun County1997 – 021987 – 921977 - 82

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Soybean Yield

y = 0.9714x + 38.767

y = -0.0857x + 45.967

y = -0.0714x + 39.333

20

25

30

35

40

45

50

55

1997 1998 1999 2000 2001 2002

Bu

/Ac

re

198519911997

Corn Yield

y = 3.8x + 134.53y = 3x + 115.67y = -2.7714x + 129.53

60

80

100

120

140

160

180

1 2 3 4 5 6

Bu

/Ac

re

198519911997

Yield Trends for Iowa6 Year Increments

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Soybean Yield

y = 2.4886x + 35.04

y = 1.02x + 40.513

y = 0.04x + 40.793

20

25

30

35

40

45

50

55

60

1997 1998 1999 2000 2001 2002

Bu

/Ac

re

1985

1991

1997

Corn Yield

y = 0.9171x + 139.77y = 4.7629x + 117.68

y = 4.2429x + 113.03

60

80

100

120

140

160

180

1 2 3 4 5 6B

u/A

cre

198519911997

Yield Trends for Calhoun County6 Year Increments

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Have Soybean Yields Reached a Plateau?

• For Calhoun County, when compared to similar time periods in the past – No

• Answer is more difficult to determine for the state

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Economics

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Shift Acres from Beans to Corn?2/09/04

• Dec. corn futures $2.83

Less basis, N. Iowa 0.35

Harvest hedge price 2.48

• Nov. soybean futures $6.49

Less basis, N. Iowa 0.45

Harvest hedge price 6.04

R. WisnerISU Econ.

Todd Vagts

• Corn/soy: Harvest hedge price $2.48Less variable prod’n costs @ 149 bu./A. (5-Yr Ave. Yield Calhoun County) 1.21Net/bu. 1.27Net/A. over variable cost $189.23

• Corn/corn: Harvest hedge price $2.48Less variable prod’n costs @ 136 bu./A. (91% of C/S) 1.60Net/bu. 0.88Net/A. $119.68Corn, Corn, SB rotation

Returns to Corn Production

Todd Vagts

• Corn/soy: Harvest hedge price $6.04Less variable prod’n costs @ 50 bu./A. 2.17Net/bu. 3.87

Net/A. $193.50

• Corn/soy: Harvest hedge price $6.04Less variable prod’n costs @ 38 bu./A. 2.86Net/bu. 3.18Net/A. (excludes aphid spraying cost) $120.84

Shift Acres from Beans to Corn?

Disease, Nematode, aphid problems

2/09/04

Todd Vagts

Economic Summary

• Return to corn– C/S Rotation

• $189 ($1.27/bu)

– C/C/S• $120 ($0.88/bu)

• Return to soybean– Low Yield

• $121 ($3.18/bu)

– High Yield• $194 ($3.87/bu)

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Other Factor to Consider

• Greater percentage of farm in one crop – increases risk

• Corn requires greater input expenses

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Pest Management Considerations

• Corn– Western Bean Cutworm– Grape colaspis

• Soybean– Soybean Aphid– Bean Leaf Beetle– Cyst Nematode– Soybean Rust (?)

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• Eggs: Small, whitish, clusters that turn purple prior to hatch

• Larvae: New larvae ¼” long and dark brown, lighten to pale brown as they mature. Full size is 1½”

• Adults: White band along most of the leading edges of forewings

LAR

VA

AD

ULT

EG

GS

Corn Pests –western bean cutworm

Todd Vagts

• Injury:Different from other

cutworms; ear feeders

Economic damage may occur when multiple cutworms feed on an ear

Injury allows pathogensinto the ear

Corn Pests –western bean cutworm

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Corn Pests – western bean cutworm

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Pyrethroids (RUP) Ambush®* Asana® XL* Capture® 2EC Baythroid® 2E Mustang® Max Pounce® 3.2EC* Warrior®

Organophosphates (RUP) Lorsban® 4E Penncap-M®

Carbamates

Sevin® XLR Plus

See “Integrated Crop Management” (http://www.ipm.iastate.edu/ipm/icm/) or product labels for correct application rates.

Insecticides for western bean cutworm

*Mite risk

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• DescriptionHoney-brown leaf

beetle

Fine tan & brown lateral stripes on grooved wing covers

Larvae are small, “C”-shaped, grubs

Corn Pests – colaspis beetles

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Corn Pests – colaspis beetlesGrubs feed on roots

Above-ground symptoms may include stunting, wilting, purpling of the stem and leaves, and tip and leaf-edge browning

Damage extent unknown

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Soybean Aphid

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Where is it now?Spread of Soybean Aphid in the US,

2000-2003

• Spread to S & W continues

• Outbreaks in 2003 primarily in western half of NC states

• Treatment occurred in DE & MD in 2003

Slide from K. Ostlie, Data from R. Venette, unpublished data

Todd Vagts

Soybean aphidDescription

– Very small, yellow aphid, 1/16 inch long

– Distinct black ‘tailpipe-like’ structures on end of

abdomen– Wingless and winged forms– Appear in colonies of adult

females and offspring– Females give birth to live

females

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(Buckthorn) (Soybean)

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How fast can a soybean aphid reproduce?

[data generated in the lab by Ragsdale et al., Univ. of Minnesota]

TempTemp68oF

77oF

86oF

95oF

LifeLifespan span (days)(days)

22

15

12

3 (die)

DoublingDoublingtime time (days)(days)

2

1.5

2

dead

TotalTotal# #

babiesbabies75

73

23

0

FirstFirstbabiesbabies

(# days)(# days) 7

5

5

--

Chris DiFonzo, Michigan State University

Todd Vagts

10.8

45.4

2.8

7.6

33.7

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Nodes

Pods/Plant

Seeds/Pod

Seed Wt.

Yield

% Reduction

Soybean Aphid Impacts on

Yield & Yield Components:

5 MN Fields in 2001

Slide from K. Ostlie, University of MN

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Sooty Mold

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Natural Enemy “Lag” TimeNatural Enemy “Lag” Time Spray Timing Critical – Aphid Resurgence Spray Timing Critical – Aphid Resurgence

FactorFactor

0

200

400

600

800

1000

1200

1400

1600

7/11 7/18 7/25 8/1 8/8 8/17 8/24 8/29 9/5

mea

n s

oybe

an a

phid

s pe

r pl

ant

0

20

40

60

80

100

nat

ura

l en

emie

s /

80

sw

eeps

soybean aphidHarmoniaOrius

LacewingNabis

Bob Ellingson and David Hogg, UW Entomology

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Product Performance & Canopy Distribution

Lorsban

Furadan

Pyrethroids

Volatile distribution through canopy.May “fume” into untreated check strips

Systemic, a.i. activity within plantin addition to contact activity

Cannot work its way through canopy beyond contact activity.

Coverage in closed canopy critical for efficacy against aphids at lower and inner locations on plant.

Eileen Cullen – UW Extension, Entomology

Todd Vagts

Product Performance & Temperature

Lorsban

Furadan

Pyrethroids

Optimal performance at higher temps.(may increase “fuming” action)

Also relatively better at higher temp

Exhibits a Negative Temp Relationship:Works better under cool conditionsbelow 90oF.

Eileen Cullen – UW Extension, Entomology

Todd Vagts

Product Performance & Residual

Lorsban

Furadan

Pyrethroids

Short residual, measured in days.

Longer residual than organophosphates.Some additional feeding exposure,due to systemic activity

Longest residual , 2 weeks or more

Eileen Cullen – UW Extension, Entomology

Todd Vagts

What to look for in 2004

• Look to areas of the northMN and Wisconsin

Areas with buckthorn and cooler temperatures

• Watch the weatherNorth Wind

Bring winged aphids in

Temperature Favorable environment for survival and

reproduction.

Todd Vagts

Wind DirectionAverage Daily Wind Direction, 2003

0

90

180

270

360

Date

Win

d D

irec

tion

(D

aily

)

NW Wind

NE Wind

Average Daily Wind Direction, 2001

0

90

180

270

360

Date

Win

d D

irec

tion

(D

ay A

vera

ge)

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Average Temperature

50

55

60

65

70

75

80

85

90

Date

Tem

per

atu

re

2003

2001

Temperature(Ames)

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IA Soybean Aphid Treatment Yield Response

Soybean Yield Response to Soybean Aphid Control(Outlier data points removed)

y = -0.4875x + 15.914

R2 = 0.4972

02468

1012141618

Treatment Day, August

Yie

ld A

dvan

tage

fro

m T

reat

men

t (b

u/A

)42 Data Points

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Threshold

- 250 aphids per plant250 aphids per plant

- assumes aphid numbers are on the increaseincrease

- provides a 7-day lead time (call in equipment, deal with weather delays)

- use through R4 (full-pod stage)

Cannot overemphasizeDROUGHT

Chris DiFonzo, Michigan State University

Todd Vagts

82 Aphids

How Many Aphids?

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850 Aphids

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49 Aphids

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11 Aphids

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• Yellow or red; with or without four square marks on wing covers

• Always with a small, black triangle behind the head

• Soft and gray when adults first emerge

Bean leaf beetles

Todd Vagts

• Key feature:

Small, black triangle behind head

Soybean Pests – bean leaf beetles

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Timing of Bean Leaf Beetle Generations

0

50

100

150

200

250

300

350

5/2

6

6/2

6/9

6/1

6

6/2

3

6/3

0

7/7

7/1

4

7/2

1

7/2

8

8/4

8/1

1

8/1

8

8/2

5

9/1 9/8

9/1

5

date

mea

n b

ean

leaf

bee

tles

Overwintering1st Generation

2nd Generation

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• Economic damage from pod feeding and by transmission of bean pod mottle virus

Soybean Pests – bean leaf beetles

L. Sweets

Pod Injury

Foliar symptoms

of virus

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Bean Leaf Beetle Population Trend

0

50

100

150

200

250

300

350

400

450

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

year

be

an le

af

be

etl

es /

50

s

we

eps

Highest abundance recorded in 14 years!

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Bean Leaf Beetle Management

Different strategies based on pest complex

A) Bean leaf beetle only

B) Bean leaf beetle + bean pod mottle virus

Todd Vagts

Timing of Bean Leaf Beetle Generations

0

50

100

150

200

250

300

3505

/26

6/2

6/9

6/1

6

6/2

3

6/3

0

7/7

7/1

4

7/2

1

7/2

8

8/4

8/1

1

8/1

8

8/2

5

9/1 9/8

9/1

5

date

mea

n b

ean

leaf

bee

tles

Overwintering1st Generation

2nd Generation

Todd Vagts

Insecticides for bean leaf beetle management

Pyrethroids (RUP) Ambush® 2EC* Asana® XL* Mustang Max®

Pounce® 3.2EC* Warrior®

Organophosphates Lorsban® 4E Penncap-M® (RUP)Carbamates Sevin® XLR Plus

See “Integrated Crop Management” (http://www.ipm.iastate.edu/ipm/icm/), or product labels for correct application rates.

* Mite risk

Todd Vagts

Soybean Cyst Nematode

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Soybean Rust

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Soybean Rust• Potential Yield Losses

– In countries in which soybean rust is an established problem, losses range from 10-80 percent. The severity of losses varies depending on susceptibility of the soybean variety, time of the growing season in which the rust becomes established in the field and weather conditions during the growing season.

• Management– Current management strategies are through the

use of resistant varieties and foliar fungicides applied during the growing season. Two to three fungicide applications may be necessary depending on disease severity.

Todd Vagts

Soybean Rust• Hosts

– Soybean, kudzu, yellow sweet clover, medic, vetch, lupine, green and kidney bean, lime or butter bean and cowpea or black-eyed pea.

• Survival– Rust pathogens survive on living plant

material. It may be able to survive the winter months on hosts such as kudzu in the southern United States. Soybean rust spores could then be carried north on wind currents and by storms.

Todd Vagts

New Developments

• Section 18 approval for Gaucho (insecticide) on soybean seed– Bean leaf beetle– Soybean aphid