Nematode Management in Corn
and Soybean
Jason Bond, Plant Pathologist
Southern Illinois University
jbond@siu.edu
618-453-4309
1
Nematodes as Pathogens
•
•
•
•
Nematodes in corn production
Why the interest now?
Potential impact of nematodes
Management options
•Soilborne Diseases of
Soybean
•Foliar Diseases of
Corn and Soybean
•Nematodes in Corn
and Soybean
Nematodes as Pathogens
• 10% of all nematodes are parasites of plants.
• Many species attack corn and soybean.
• Generally, the nematode and symptoms are not
seen.
• Host resistance is the exception.
Nemapix
What is a Nematode
NEMATODA
PLATYHELMINTHES
ANNELIDA
Arthropoda
Pseudocoelomata
Mollusca
Acoelomata
“FLATWORMS”
Coelomata
“ROUNDWORMS”
Hydras, Jellyfish
Sea urchins
Radial
Symmetry
Higher Animals
(Vertebrates)
Bilateral Symmetry
ANIMALIA
Courtesy of EC McGawley, LSU
PHYLUM: NEMATODA
10%
Plant
15% Animal
25% Free-Living
Marine
50%
Courtesy of EC McGawley, LSU
Courtesy of EC McGawley, LSU
Non-Plant Parasites
Courtesy of EC McGawley, LSU
PLANT PARASITIC NEMATODES
ENDOPARASITES
Root-Knot Nematode
Lesion Nematode
ECTOPARASITES
Dagger Nematode
Needle Nematode
Images courtesy of Nemapix
How Nematodes Feed
Images courtesy of Nemapix
Nematodes in Corn
•
•
•
•
•
•
•
•
•
•
Common Name
Sting nematode
Needle nematode
Stubby rt. nematode
Lance nematode
Root-lesion nematode
Dagger nematode
Root-knot nematode
Stunt nematode
Spiral nematode
Ring nematode
Scientific Name
Belonolaimus spp.
Longidorus spp.
Paratrichodorus spp.
Hoplolaimus spp.
Pratylenchus spp.
Xiphinema spp.
Meloidogyne spp.
Tylenchorhynchus spp.
Helicotylenchus spp.
Mesocriconema spp.
Most of these nematodes are ubiquitous in the U.S.
Nematodes in Corn
•
•
•
•
•
•
•
•
•
•
Common Name
Damage Thresholds (½ cup soil)
Sting nematode
1 to 6 = moderate damage
25+ = severe damage
Needle nematode
Stubby rt. nematode -----50+ = severe damage
Lance nematode
Root-lesion nematode
150+ = moderate damage
Dagger nematode
Root-knot nematode
Stunt nematode
Spiral nematode
= Weak pathogens
Ring nematode
Soil Type = Greater Risk
Sandy Soil
Sting nematode
Needle nematode
Stubby rt. nematode
Ring nematode
Lance nematode
Root-knot nematode
Stunt nematode
Spiral nematode
Dagger nematode
Root-lesion nematode
“Traditional Soil”
Stunt nematode
Lance nematode
Root-lesion nematode
Dagger nematode
Spiral nematode
Nematode Pathogens
Corn
“Stunters” - found in sandy fields, yield loss can be
devastating
- Needle, Sting, Dagger and Stubby Root
Nematodes
“Debilitators” - found in traditional soil types, yield loss
is often mild to moderate
- Lesion, Stunt, Spiral and Lance Nematodes
Images courtesy of Nemapix
Impact of corn nematodes - 2004
Counter 20 CR
No Counter
6
3
2
5
4
1
Counter
No Counter
Avg. Nematodes/100 cc soil
No Counter
165 a
Counter
43 b
Nematode Population Densities
Nematodes/ 100 cc soil
Sample
Dagger
Lesion
Spiral
Sting
Total
Important
Nemas
1 Non-treated
156
8
328
57
549
221
2 Non-treated
82
33
123
1
239
116
3 Non-treated
66
25
57
66
214
157
4 Treated
16
8
114
1
139
25
5 Treated
41
16
254
10
321
67
6 Treated
21
11
206
4
242
36
Sting nematode was present
~ 30 acres
Counter
Non-treated
163 bu/acre
130 bu/acre
100 acres most without sting
Counter
166 bu/acre
Non-treated
162 bu/acre
Carmi, SE Illinois 2005
130+ Sting nematodes/100 cc soil
(Damage threshold is 1-5 /100 cc soil)
Carmi, SE Illinois 2008
• Moderate – 7 needle nemas/100 cc soil
Carmi, SE Illinois 2008
• Severe – 50 needle nemas/100 cc soil
Needle Dagger
331
42
Where have The nematodes been?
• They are “natives” with only a few exceptions
• Insect management via host resistance = less soil
applied insecticides = happier nematodes
• Reduced tillage – several species prefer to live in soil
that is not disturbed
• Less diverse rotations – corn followed by corn is
preferred by most of these nematodes
– Rotational crops soybean, cotton, alfalfa, vegetables, etc. are hosts to most of
these nematodes.
Consistency?
•
Active ingredient and/or formulation
•
Amount/distribution of the pathogen
•
Virulence of the pathogen
•
Environment/weather
•
Soil characteristics
•
Host genetics
•
Cultural practices
•
etc.
Soil Applied
Needle and Dagger Nematodes - Irrigated field - Carmi, IL 2009
a
b
ab
4.5 oz / 1000’
6 oz / 1000’
6 rep trial
Bayer Seed Treatments
Needle and Dagger Nematodes - Irrigated field in Carmi, IL 2008
a
b
b
Seed Treatments
6 rep trial
Bayer Seed Treatments
Needle and Dagger Nematodes - Carmi - 2009
Standard = Vortex,
Allegiance, Poncho
Seed Treatments
6 rep trial
Bayer Seed Treatments
Lesion, lance, spiral and stunt nematodes - Shawneetown - 2009
Standard = Vortex,
Allegiance, Poncho
Seed Treatments
6 rep trial
Seed Treatments
6 rep trial
Fungicide/Insecticide/A
CTA
190.2
bu/A
Non-treated
168.2 bu/A
Fungicide/Insecticide
170.7 bu/A
Carmi, IL 2009
Syngenta Seed Treatments
Needle and Dagger Nematodes - Irrigated field in Carmi, IL 2009
Standard = Maxim, Apron,
Dynasty, Cruiser
Seed Treatments
6 rep trial
Maxim, Apron XL,
Dynasty, Cruiser
Maxim, Apron XL,
Dynasty, Cruiser +
AVICTA
General Info
• Obvious symptoms are not common!
• Yield losses vary depending on nematode
population densities, species present, etc.
• Corn is at greatest risk in seedling stage
- High moisture in April-June, cool soils, poor growing
conditions = perfect storm for corn damage
• Some species are active only from early to midseason.
When to Sample?
Lesion,
Root knot,
Lance,
Stubby Rt.
Detection,
Diagnosis
Damage
Damage
Sting, Needle,
Dagger
Detection,
Diagnosis
Damage
Damage
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Crop in Ground
Dec
• Combined with yield maps, sampling can help diagnose problem
areas
• Provides a background on types and density
Note: Corn nematode ID is much more time and resource consuming than for
soybean cyst nematode.
Nematode Pathogens
Soybean
•
Soybean cyst nematode - 90% of varieties are
resistant, virulence management issues
•
Root knot nematode - 7% of varieties are resistant
Nematode Resistance in
Soybean
•
All resistant varieties allow juveniles to invade the
roots.
•
Resistance is expressed later during the feeding,
development and/or reproduction of the females.
•
Juveniles cause damage on entry and with
movement in the roots.
•
Entry causes portals for pathogens that cause
diseases like SDS, BSR, etc.
Status of Resistance in SCN-Resistant
Varieties
SCN Population: SCN HG Type 0, (Race 3),
~550 SCN-resistant varieties, each year
2002
2009
J. Bond, 2009 www.vipsoybeans.org
Status of Resistance in SCN-Resistant
Varieties
SCN Population: SCN HG Type 2,
550 SCN-resistant varieties
2009
J. Bond, 2009 www.vipsoybeans.org
Soybean yield (bu/A)
Bayer SCN Research
Control
Exp6
VOTiVO
VOTiVO+
Gaucho
Gaucho
Control+
Fungicide
Carmi, IL 2008
soybean Seed Treatments
Bayer nematicide seed treatments - Carmi - 2009
Seed Treatments
6 rep trial
Summary
• Nematode problems in corn and soybean are
going to get worse in the near term.
• A “frequent” (once every 4-6 years) sampling
plan is required to manage nematodes.
• Sampling and detection issues
– Handling, time consuming to process and
identify, more expensive ($25+), experienced
technicians required, etc.
• Nematode diagnosis – Quality3
Diagnostic Labs
Southern Illinois University
Plant, Soil, and Ag. Sys.
1205 Lincoln Dr.,
Ag. 176
Carbondale, IL 62901
618-453-4309
University of Illinois
Crop Sciences
AW101 Turner Hall
1102 S. Goodwin Ave.
Urbana, IL 61801
217-265-5405
Purdue University
Entomology
901 W. State Street
West Lafayette, IN
47907-2089
765-494-5901
Jason Bond
jbond@siu.edu
Terry Niblack
tniblack@illinois.edu
Jamal Faghihi
jamal@purdue.edu
Any Questions?
Jason P. Bond
jbond@siu.edu
618-453-4309