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Nematode Management in Corn and Soybean

Jason Bond, Plant PathologistSouthern Illinois University

jbond@siu.edu618-453-4309

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

ANIMALIA

Radial Symmetry Bilateral Symmetry

“ROUNDWORMS”

“FLATWORMS”Coelomata

AcoelomataPseudocoelomata

NEMATODAPLATYHELMINTHES

Arthropoda

Mollusca

ANNELIDA

Higher Animals(Vertebrates)

Hydras, JellyfishSea urchins

What is a Nematode

Courtesy of EC McGawley, LSU

50%

10%

15%25%

Plant

Animal

Free-Living

Marine

PHYLUM: NEMATODA

Courtesy of EC McGawley, LSU

Courtesy of EC McGawley, LSU

Non-Plant Parasites

Courtesy of EC McGawley, LSU

ENDOPARASITES

ECTOPARASITES

Lesion Nematode

Dagger Nematode

Root-Knot Nematode

PLANT PARASITIC NEMATODES

Images courtesy of Nemapix

Needle Nematode

Images courtesy of Nemapix

How Nematodes Feed

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 NameBelonolaimus 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• Sting nematode• Needle nematode• Stubby rt. nematode

------• Lance nematode• Root-lesion nematode• Dagger nematode• Root-knot nematode• Stunt nematode• Spiral nematode• Ring nematode

Damage Thresholds (½ cup soil)

1 to 6 = moderate damage

25+ = severe damage

50+ = severe damage

150+ = moderate damage

= Weak pathogens

Soil Type = Greater Risk Sandy SoilSting nematodeNeedle nematodeStubby rt. nematodeRing nematodeLance nematodeRoot-knot nematodeStunt nematodeSpiral nematodeDagger nematodeRoot-lesion nematode

“Traditional Soil”Stunt nematodeLance nematodeRoot-lesion nematodeDagger nematodeSpiral nematode

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

Nematode Pathogens

Images courtesy of Nemapix

Counter 20 CR

No Counter

Impact of corn nematodes - 2004

1

23

4

56

Avg. Nematodes/100 cc soilNo Counter 165 a

Counter 43 b

Counter

No Counter

Nematode Population Densities

Sample Dagger Lesion Spiral Sting Total ImportantNemas

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

Nematodes/ 100 cc soil

Sting nematode was present~ 30 acres

Counter 163 bu/acreNon-treated 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.

Needle and Dagger Nematodes - Irrigated field - Carmi, IL 2009

4.5 oz / 1000’

b

a

ab

Soil Applied

6 oz / 1000’ 6 rep trial

Seed Treatments

b

a

b

Bayer Seed TreatmentsNeedle and Dagger Nematodes - Irrigated field in Carmi, IL 2008

6 rep trial

Seed Treatments

Bayer Seed TreatmentsNeedle and Dagger Nematodes - Carmi - 2009

6 rep trialStandard = Vortex, Allegiance, Poncho

Seed Treatments

Bayer Seed TreatmentsLesion, lance, spiral and stunt nematodes - Shawneetown - 2009

6 rep trialStandard = Vortex, Allegiance, Poncho

Carmi, IL 2009170.7 bu/A

168.2 bu/A

190.2 bu/A

Seed Treatments

Non-treated

Fungicide/Insecticide

Fungicide/Insecticide/AVICTA

6 rep trial

Seed Treatments

Syngenta Seed TreatmentsNeedle and Dagger Nematodes - Irrigated field in Carmi, IL 2009

6 rep trialStandard = Maxim,

Apron, Dynasty, Cruiser

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 mid-season.

When to Sample?Lesion, Root knot,Lance,Stubby Rt.

Sting, Needle,Dagger

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Crop in Ground

Damage

Detection, Diagnosis

DamageDamage

• 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.

Detection, Diagnosis

Damage

Soybean

• Soybean cyst nematode - 90% of varieties are resistant, virulence management issues

• Root knot nematode - 7% of varieties are resistant

Nematode Pathogens

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.

2002 2009

SCN Population: SCN HG Type 0, (Race 3),~550 SCN-resistant varieties, each year

Status of Resistance in SCN-Resistant Varieties

J. Bond, 2009 - www.vipsoybeans.org

2009

SCN Population: SCN HG Type 2, 550 SCN-resistant varieties

Status of Resistance in SCN-Resistant Varieties

J. Bond, 2009 - www.vipsoybeans.org

Bayer SCN Research

So

ybea

n y

ield

(b

u/A

)

Control Exp6 VOTiVO VOTiVO+ Gaucho Control+ Gaucho Fungicide

Carmi, IL 2008

Seed Treatments

soybean Seed TreatmentsBayer nematicide seed treatments - Carmi - 2009

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 LabsSouthern Illinois UniversityPlant, Soil, and Ag. Sys.1205 Lincoln Dr., Ag. 176Carbondale, IL 62901618-453-4309

Jason Bondjbond@siu.edu

Purdue UniversityEntomology901 W. State StreetWest Lafayette, IN 47907-2089765-494-5901

Jamal Faghihijamal@purdue.edu

University of IllinoisCrop SciencesAW101 Turner Hall1102 S. Goodwin Ave.Urbana, IL 61801217-265-5405

Terry Niblacktniblack@illinois.edu

Any Questions?

Jason P. Bondjbond@siu.edu618-453-4309