Wheat Management

Mike Roegge

University of Illinois Extension

Adams/Brown Unit

With special thanks to Dr. Carl Bradley, Dr. Steve Ebelhar, Dr. Eric Adee

Fusarium Head Blight – Scab

• Caused by the fungus: Fusarium graminearum

• Bleached heads• Healthy spikelets

remain green• Same organism

causes Fusarium stalk rot in corn

Conditions favorable for Fusarium head blight

• Flowering thru kernel development– Prolonged periods of

high humidity– Moderate

temperatures = 75 to 85°F

– Prolonged wet periods

Scab Incidence in Wheat, Monmouth, (1997, 98, 2001-2004)

0

5

10

15

20Sc

ab (

%)

Corn Soybean

Previous Crop

TillNo-till

Proline Fungicide

• Full registration last year on wheat (2007)

• Prothioconazole is the active ingredient (triazole)

• Applied at 4.3 to 5.7 fl oz/A

• Has been evaluated in Illinois wheat scab fungicide trials (applied at early anthesis – Feekes 10.51)

What’s available for scab control in 2008?

• Proline (prothioconazole) – fully registered in 2007– Apply at early anthesis (Feeke’s

10.5.1)

• Never spray a fungicide that contains a strobilurin (Headline, Quadris, Quilt, Stratego) component at this stage!– Vomitoxin (DON) levels can increase

Monmouth, IL - 2003

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60

80

100

120

140

FHB Yield

untreatedFolicurProline

Eric Adee, Univ. IL

Monmouth, IL - 2004

0

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FHB DON Yield

untreatedFolicurProlineProsaro

Eric Adee, Univ. IL

Urbana Wheat Fungicide Trial – 2007

Fungicide Scab (%) DON (ppm)

Test wt (lb/bu)

Yield (bu/A)

Untreated 57 0.43 60.1 54.9

ProLine @ 5 fl oz/A

30** 0.26 59.9 52.6

Monmouth Wheat Fungicide Trial – 2007

Fungicide Scab (%) DON (ppm)

Test wt (lb/bu)

Yield (bu/A)

Untreated 22 0.40 57.8 54.7

ProLine @ 5 fl oz/A

14 0.39 57.8 52.1

Data courtesy Eric Adee, Univ. of Illinois

Summary of University of Illinois trials with Proline

• Can consistently reduce scab disease levels and DON levels in harvested grain

• Not enough “high disease pressure” trials to always observe significant yield differences

Wheat Scab Management

• Infects wheat when flowering

• Requires high humidity/rain for spore production and infection

• Favored by mild temperatures (65-86o F)

• Scab Risk Tool: http://www.wheatscab.psu.edu

www.wheatscab.psu.edu

What about control of diseases other than scab?

• Other diseases- Leaf and glume blotch, tan spot, rusts

• Can control other diseases at the 10.51 timing (scab timing), but may be able to have better control of lead diseases at an earlier timing……..flag leaf to early heading (9 to 10.1)

• Protect the flag leaf!

Spring Scouting for Diseases

Protect the Flag LeafSeptoria Leaf BlotchPowdery MildewRust

Protect the Head

Managing Leaf, Glume, Rust Diseases

• Crop rotation– Stubble-borne diseases

• Resistant varieties

• Fungicides– Some control with “scab” timing– Better control earlier……..protect the flag leaf!

http://vt.cropsci.uiuc.edu/

Fungicides for leaf, glume, rust diseases

• Many available

• Triazoles – Proline, Tilt (Curative)

• Strobilurins – Headline, Quadris (Protectant)

• Mixtures – Stratego, Quilt

2003 to 2007 Illinois SummaryUIUC and SIUC trials

-16-12

-8-4048

12162024

Location, variety, year

Yie

ld d

iffer

ence

(bu/

A)

Data from Belleville, Brownstown, Carbondale, Dixon Springs, Urbana.

Applications made at or near flag leaf emergence.

UIUC trials = S. Ebelhar and C. Bradley; SIUC trials = B. Young

Overall average = 3 bu/A over the untreated

Fungicides for leaf, glume, and rust diseases

• Bigger benefits observed on more susceptible varieties

• Timing = flag leaf emergence may provide the best protection of flag leaf- label restrictions on most to restrict application to: 1) before flowering or 2) before flag leaf finished emerging

• Application at flowering - will get some protection of leaf diseases, but don’t apply a strobilurin product at this stage

• Scout at flag leaf emergence and thereafter, idea is to protect flag leaf (80% of fill?)

Spray or Not?

1. Does the field appear to have adequate yield potential 2. Has there been rainy weather or heavy dews the week

going into flag leaf emergence........and is this weather expected to continue? 

3. How susceptible is the variety to leaf diseases (rust, septoria, etc.)

4. The Cereal Rust Bulletin (http://www.ars.usda.gov/Main/docs.htm?docid=9757) is a good way to find out if rusts are headed north.  If some of the rusts are approaching and the weather has been favorable for disease, then this should also be another level of consideration for a fungicide.

Dr. Carl Bradley, 2-26-08

Efficacy of fungicides for wheat disease control based on appropriate application timing Product Fungicide(s) Rate/A

(fl. oz) Powdery mildew

Stagonospora leaf/glume blotch

Septoria leaf blotch

Tan spot

Stripe rust

Leaf rust

Head scab

Headline 2.09 EC

Pyraclostrobin 23.6%

6.0 to 9.0 G1 VG VG E E2 E NR Strobilurin

Quadris 2.08 SC

Azoxystrobin 22.9%

6.2 to 10.8 F(G)3 VG VG E E2 E NR

Proline 480 SC

Prothioconazole 41%

5.0 to 5.7 --4 VG VG VG -- VG G(VG)3

PropiMax 3.6 EC

Propiconazole 41.8%

4.0 VG VG VG VG VG VG F

Triazole

Tilt 3.6 EC

Propiconazole 41.8%

4.0 VG VG VG VG VG VG F

Quilt 200 SC

Azoxystrobin 7.0% Propiconazole 11.7%

14.0 VG VG VG VG E E NR Premix

Stratego 250 EC

Propiconazole 11.4% Trifloxystrobin 11.4%

10.0 G VG VG VG VG G NR

Section 18 triazole5

Folicur 3.6 F

Tebuconazole 38.7%

4.0 G VG VG VG E E G

1 Efficacy categories: NR=Not Recommended; F=Fair; G=Good; VG=Very Good; E=Excellent 2 Efficacy may be significantly reduced if solo strobilurin products are applied after infection of has

occurred 3 (G) indicates greater efficacy at higher application rates 4 Insufficient data to make statement about efficacy of this product 5 Folicur does not currently have a federal label, but may be labeled or have Section 18 emergency

registration in some states in 2008