Disease control of irrigated crops
Martin Chilvers Department of Plant, Soil and Microbial Sciences
[email protected] @MartinChilvers1 517-353-9967
www.fieldcroppathology.msu.edu
Northern Corn Leaf Blight
Exserohilum turcicum (Setosphaeria turcica)
Gray Leaf Spot
Cercospora zeae-maydis
Gray Leaf Spot
Common Rust
Puccinia sorghi
Northern Corn Leaf Spot
Bipolaris zeicola (Cochliobolus carbonum)
Northern Corn Leaf Spot
Corn fungicide trials
Break-even scenarios for corn Corn price
($/bu)
Application cost ($/A)
$12 $16 $20 $24 $28 $32 $36
$3.00 4.0 5.3 6.7 8.0 9.3 10.7 12.0
$4.00 3.0 4.0 5.0 6.0 7.0 8.0 9.0
$5.00 2.4 3.2 4.0 4.8 5.6 6.4 7.2
$6.00 2.0 2.7 3.3 4.0 4.7 5.3 6.0
$7.00 1.8 2.3 2.9 3.4 4.0 4.6 5.1
$8.00 1.5 2.0 2.5 3.0 3.5 4.0 4.5
$9.00 1.3 1.8 2.2 2.7 3.1 3.6 4.0
$10.00 1.2 1.6 2.0 2.4 2.8 3.2 3.6
2014, Michigan corn fungicide trials
0
20
40
60
80
100
120
140
160
180
200
Untreated Priaxor, 8 ozV6
Priaxor, 8 ozVT
Priaxor, 8 ozV6&VT
Stratego YLD,5 oz V6
Stratego YLD,5 oz VT
Stratego YLD,5 oz V6&VT
Yiel
d (b
u/A)
Coleman
East Lansing
Coleman: DKC38-04RIB , East Lansing: NuTech 5V197 Low levels of Rust, GLS, NLB <1.5 DIX scores
2014, Michigan corn fungicide trials
-30
-20
-10
0
10
20
30
40
Priaxor, 8 oz V6 Priaxor, 8 oz VT Priaxor, 8 ozV6&VT
Stratego YLD, 5oz V6
Stratego YLD, 5oz VT
Stratego YLD, 5oz V6&VT
Yiel
d re
lativ
e to
unt
reat
ed (b
u/A)
Coleman
East Lansing
2015, MSU corn trials – NCLB (DSI)
0
1
2
3
4
5
6
7
8Ea
r Lea
f Dis
ease
Sev
erity
Inde
x
2015, MSU corn trials – Yield (bu/A)
020406080
100120140160180200
Yiel
d (b
u/A)
-50
-40
-30
-20
-10
0
10
20
30
cont
rol
Affia
nce
(10
fl oz
/A) @
V5
Affia
nce
(10
fl oz
/A) @
VT
Dom
ark
230M
E (4
fl o
z/A)
@V5
Dom
ark
230M
E (4
fl o
z/A)
@VT
Equa
tion
SC (6
fl o
z/A)
@V6
Equa
tion
SC (6
fl o
z/A)
@VT
Fort
ix (5
fl o
z/A)
@V6
Fort
ix(5
fl o
z/A)
@V8
Fort
ix (5
fl o
z/A)
@VT
Fort
ix (4
fl o
z/A)
@VT
Head
line
AMP
(10
fl oz
/A) @
V8
Head
line
AMP
(10
fl oz
/A) @
VT
Stra
tego
YLD
(2 fl
oz/
A) @
V5
Stra
tego
YLD
(4 fl
oz/
A) @
VT
Stra
tego
YLD
(5 fl
oz/
A) @
V5 a
nd V
T
Topg
uard
EQ
(5 fl
oz/
A) @
V6
Topg
uard
EQ
(5 fl
oz/
A) @
V8
Topg
uard
EQ
(5 fl
oz/
A) @
VT
Yiel
d de
lta
Early V vs. VT
Corn fungicide conclusions • Variability in data sets and fields:
– Northern states showed high variation—difficult to link yield response to disease severity in all cases
– Some environment related, but yearly variability exists
• Continue to see best economic response from
fungicides when used in response to disease pressure – VT application
Kiersten Wise
Should I be using a foliar fungicide? • On farm trials • Require replication
Goss’s Wilt Remerging Bacterial disease New York Times Sep-30-2013
Goss’s wilt distribution
2013 outbreak in Louisiana
Scouting for Goss’s wilt in Michigan
Why the increase in Goss’s wilt?
• Change in production systems • Corn on corn • Min. or no-till systems • Susceptible hybrids • Change in virulence of the Cmn pathogen • Fungicides are not effective
Tar spot of corn Phyllachora maydis, and Monographella maydis
Only Phyllachora maydis confirmed to date Purdue Diagnostic lab and Kiersten Wise
White mold – 2014
Adjusted to 1bu/A Photo courtesy: Martin Nagelkirk
Peltier et al., 2012
Foliar fungicides – White mold
2014, white mold disease index (DSI)
0
10
20
30
40
50
60
70
80
90
100
Dise
ase
(DIX
)
Disease pressure too high to statistically differentiate treatments
2014, white mold yield
0
5
10
15
20
25
30
35
40Yi
eld
bu/A
Endura 6oz (R1) + Priaxor 4oz (R3); Endura 6oz (R1); Stratego YLD 4oz (R3); Aproach 9oz (R3); Endura 8oz R3; Cobra 6oz + Endura 8oz (R1)
*
2015, white mold trial - Disease
* * *
0
10
20
30
40
50
60
70
80
Whi
te m
old
(DIX
)
• Topsin 30 oz @R1 and R2; • Cobra 6oz + Endura 8oz @R1; • Cobra 6oz @V5
2015, white mold trial - Yield *
0
10
20
30
40
50
60
70
Yiel
d (b
u/A)
Only treatment significantly different to control: Propulse 8oz @R1 + Proline 3oz @R3
When to spray? 2014, application timing
0
5
10
15
20
25
30
Cont
rol
Apro
ach
9 flo
z R2
Apro
ach
9flo
z R3
Endu
ra 8
oz R
1
Endu
ra 8
oz R
3
Yiel
d bu
/A
White mold - Chemical control
• Chemical control as protectant not curative • Application timing to protect flowers up to
beginning pod (R3) • Canopy penetration is essential • Have realistic management expectations
Management of White Mold in Soybean • No silver bullets – must integrate several
management practices: – Partially-resistant varieties
• MSU variety trials www.varietytrials.msu.edu
– Row spacing and seeding population rates
Sudden Death Syndrome (SDS)
SDS has become a significant concern across the Midwest
Complex Disease: • Root rot • Foliar symptoms
Soybean SDS – Michigan
2015
2013
2012
2011
2010
2009
Fusarium virguliforme life cycle
First found Arkansas in 1970
Commercial cultivars – differ in resistance
2014, Yield ILeVO vs. base treatment
-2-10123456
11 2 9 5 6 8 1 7 12 10 3 4Yiel
d re
lativ
e to
bas
e tr
eatm
ent (
bu/A
)
Cultivars
2014, SCN reproduction ratio (Pf/Pi)
0
2
4
6
8
10
12
14
1 2 3 4 5 6 7 8 9 10 11 12
SCN
Pf/
Pi
treateduntreated
SDS management recommendations Prevent movement of infested soil power wash equipment if possible
Confirm it is SDS Utilize resistant varieties ILeVO seed treatment Test and manage for SCN Improve drainage Extended crop rotation may help
Irrigation management for soybeans
Heavy applications favor SDS Many light applications favor white mold
Acknowledgements • Dr. Carl Druskovich, • MSU diagnostic lab, Fred and Jan • John Boyse and Randy Laurenz • Tim Dietz and Kyle Johnson • Kerrek Griffes, Steve Gower - Asgrow • Karen Zuver – Pioneer • Bill Widdicombe and Lori Williams • Midwest colleagues: Kiersten Wise et al.