Field Crops Disease Update
Gary C C. Bergstrom Department of Plant Pathology Cornell University
G.C. Bergstrom
North Country Crop Congresses M d id and Madrid d Carthage, C th New N York Y k March 12-13, 2008
Common fungal leaf blights of corn in New York
Common rust
Gray leaf spot
Northern leaf blight
Northern leaf spot
Eyespot
Anthracnose leaf blight
Leaf blights can dramatically reduce corn yields Northern leaf blight
Photo courtesy of Chris Daum
Leaf blights also predispose plants to root/stalk rots
G.C. Bergstrom
G.C. Bergstrom
Current management of fungal leaf blights in New York •Adapted Ad t d h hybrids b id with ith resistance i t to t prevalent l t diseases! di ! •Rotational sequence q / debris management g •Timely planting and harvest •Stress reduction (fertility, insects, weeds) •Foliar F li fungicide f i id application li ti ???
G.C. Bergstrom
Perfect storm for foliar fungicide application to corn in the Midwest in 2007
•High corn price (ethanol demand) •Perceived higher disease risk (corn after corn) •Availability Availability of effective effective, broad broad-spectrum spectrum fungicides (strobilurins) •Lowered ‘break-even’ yield response for fungicide (5-6 bu/A) •Anticipated yield benefits beyond disease control Plant HealthTM / Plant PerformanceTM effects
Acknowledgements: This presentation includes data, slides, and ideas generously provided by several persons and organizations, including:
NCDC-214, NCDC 214, Corn Disease Management Committee Pioneer Hi-Bred Intl., Inc. - Dr. Tom Doerge Iowa State University - Dr. Gary Munkvold and Dr. Alison Robertson University of Illinois - Dr. Carl Bradley Growmark, Inc. - Dr. Ron Hines BASF Corp., Corp Bayer CropScience, CropScience Syngenta Crop Protection
Some commonly applied corn fungicides
Fungicide F i id product
Active A ti ingredients
Fungicide F i id family
C Company
Headline
pyraclostrobin
strobilurin
BASF Corp.
Quilt
azoxystrobin y & propiconazole
strobilurin & triazole
Syngenta y g Crop Protection
Stratego
trifloxystrobin & propiconazole
strobilurin & triazole
Bayer CropScience
A major influence on fungicide use Plant HealthTM / Plant PerformanceTM effects of strobilurin fungicides •Delayed plant senescence •Ethylene reduction •Oxidative stress reduction •Increased water use efficiency •Increased photosynthetic efficiency
Fungicide g application pp results
Pioneer summary of university and strip trials (2006(20062007) Iowa State University – coordinated trials (2007) University of Illinois summary of university trials (2007)
From: Gary Munkvold, Tom Doerge, and Carl Bradley. Presentation at December 2007 ASTA Meeting
Corn Response to Foliar Fungicides Influence of GLS resistance of Pioneer hybrids
20
(5) (11)
18 16
(15)
14
(47)
12 10 8 6
(23)
4 2 0 2
3
Susceptible
4
5
Moderately Resistant
6
Resistant
Pioneer Rating for Gray Leaf Spot (1 to 9 scale) 58 hybrids, 101 trials
Tom Doerge, Pioneer
Corn Response to Foliar Fungicides Influence of previous crop crop, disease level level, and tillage
Previous crop
Yield increase
Corn
12.1 bu/acre 1.5
(23)
Soybeans y
((32))
Disease pressure
Yield increase
Yes
15.3 bu/acre 3.5
No
(27)
(9)
Tillage: 6.2 bu/are conventional; 8.2 bu/acre no-till/strip till Tom Doerge, Pioneer
Yield response to fungicide application - IA 25
Overall yyield response p = 3.3 bu/A Positive yield response = 77% (20/26) Economically beneficial = 27% (7/26)
20
Yield res sponse (bu//A)
15 10
6 bu/A
5 0
1
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
2 0
2 1
2 2
2 3
2 4
-5 10 -10 -15
R. Elmore L. Abendroth A. Robertson (IA St. Univ.)
-20 20
= fc x hybrid replicated
= fc (side-by-side)
= fc (replicated)
2 5
2 6
2007 University Corn Fungicide Trials U i University it off IL S Summary, D Dr. C Carll B Bradley dl • States/Province in which trials were conducted: – Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Minnesota, Missouri, Nebraska, North Dakota, Ohio, Ontario and Wisconsin Ontario,
• Mixture of on-farm strip p trials and small-plot p trials (majority were small-plot trials) • All had a minimum of 3 replicates per location
2007 University Corn Fungicide Trials U i University it off IL S Summary, D Dr. C Carll B Bradley dl • Majority of trials were sprayed by ground applicator – only 3 trials were sprayed by aerial applicator • F Fungicide i id applications li ti were made d between VT and R1
2007 University Corn Fungicide Trials U i University it off IL S Summary, D Dr. C Carll B Bradley dl • Each data p point equals q a unique q location or unique hybrid (i.e. multiple hybrids at the same location each have their own data point) • Fungicide treatment = $20/A • Market price of corn = $3.50/bu • Need 6 bu/A return to be profitable
Yield overr untreated
Headline 6 fl oz, Quilt 14 fl oz, Stratego 10 oz 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 Location or Hybrid
61 out of 162 = 38% of the time had a yield increase of 6 bu/A or greater. Mean = 3 bu/A increase over the untreated
University of IL summary
Conclusions from University Trials (University of IL summary) • Overall, a foliar fungicide application would have been profitable fit bl 38% off the th time, ti and d overallll mean was 3 b bu/A /A b better tt than the untreated • Fungicides applied to hybrids with Fair to Poor resistance to GLS would have been profitable 50% of the time, with a mean of 6 bu/A better than the untreated (as opposed to 39% of the time with good to excellent resistance) • P Previous i crop being b i corn did nott make k ffungicide i id applications li ti more profitable than previous crop being soybean, sugarbeet, or wheat……..Impact of tillage????
2007 Midwest Fungicide Experience • Ten to 14 million acres received a fungicide application – Uncertain whether corn producers profited from f fungicide i id applications li ti (2006 > 2007)
• Many acres were sprayed unnecessarily – Possibly P ibl ½ off th the producers d llostt money iin 2007
• Available IPM practices were not employed – Fungicides can be used much more responsibly and efficiently From: Gary Munkvold, Tom Doerge, and Carl Bradley. Presentation at December 2007 ASTA Meeting
Are foliar fungicides an option in New York? YES, but we don’t know when and where YES pp will be p profitable application
Corn growers are encouraged to ‘experiment’ with registered corn fungicides in replicated strip plots p Extension field crop p educators Cornell Cooperative are available to provide advice
Climbing the “Probability Ladder” for economic benefit from fungicides • • • • • • • •
Susceptible hybrid Continuous corn No-till corn after corn Grain p production region g (more corn debris) Late planting High yield potential Irrigation Disease activity at tasseling / forecast weather
High probability
Low probability Modified from L. Rhodes (Ohio State U.) and P. Vincelli (U. of Kentucky)
Hybrid resistance to specific pathogens Susceptible
Resistant Northern leaf blight
Photo courtesy of Chris Daum
Northern leaf blight
Thanks for your attention! Questions or comments?
G.C. Bergstrom