1 Nematode Management in Corn and Soybean Jason Bond, Plant Pathologist Southern Illinois University

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 Acoelomata Pseudocoelomata NEMATODA PLATYHELMINTHES Arthropoda Mollusca ANNELIDA Higher Animals (Vertebrates) Hydras, Jellyfish Sea 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

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 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 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 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

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

Avg. Nematodes/100 cc soil No Counter165 a Counter 43 b Counter No Counter

Nematode Population Densities SampleDaggerLesionSpiralStingTotalImportant Nemas 1 Non-treated Non-treated Non-treated Treated Treated Treated Nematodes/ 100 cc soil

Sting nematode was present ~ 30 acres Counter 163 bu/acre Non-treated 130 bu/acre 100 acres most without sting Counter 166 bu/acre Non-treated 162 bu/acre

Carmi, SE Illinois 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

NeedleDagger 33142

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 oz / 1000’ b a ab Soil Applied 6 oz / 1000’ 6 rep trial

Seed Treatments b a b Bayer Seed Treatments Needle and Dagger Nematodes - Irrigated field in Carmi, IL rep trial

Seed Treatments Bayer Seed Treatments Needle and Dagger Nematodes - Carmi rep trial Standard = Vortex, Allegiance, Poncho

Seed Treatments Bayer Seed Treatments Lesion, lance, spiral and stunt nematodes - Shawneetown rep trial Standard = Vortex, Allegiance, Poncho

Carmi, IL bu/A bu/A bu/A Seed Treatments Non-treated Fungicide/Insecticide Fungicide/Insecticide/AVI CTA 6 rep trial

Seed Treatments Syngenta Seed Treatments Needle and Dagger Nematodes - Irrigated field in Carmi, IL rep trial Standard = 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 JanFebMarAprMayJunJulAugSepOctNovDec Crop in Ground Damage Detection, Diagnosis Damage 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.

SCN Population: SCN HG Type 0, (Race 3), ~550 SCN-resistant varieties, each year Status of Resistance in SCN-Resistant Varieties J. Bond,

2009 SCN Population: SCN HG Type 2, 550 SCN-resistant varieties Status of Resistance in SCN-Resistant Varieties J. Bond,

Bayer SCN Research Soybean yield (bu/A) Control Exp6 VOTiVO VOTiVO+ Gaucho Control+ Gaucho Fungicide Carmi, IL 2008

Seed Treatments soybean Seed Treatments Bayer nematicide seed treatments - Carmi 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 – Quality 3

Diagnostic Labs Southern Illinois University Plant, Soil, and Ag. Sys Lincoln Dr., Ag. 176 Carbondale, IL Jason Bond Purdue University Entomology 901 W. State Street West Lafayette, IN Jamal Faghihi University of Illinois Crop Sciences AW101 Turner Hall 1102 S. Goodwin Ave. Urbana, IL Terry Niblack

Any Questions? Jason P. Bond