in this lecture, you will learn about strategies used for the integrated nematode management for field crops.

1. Integrated management of plant-
parasitic nematodes
Rufus J. Akinrinlola
PhD Student and Graduate Research Assistant
Entomology and Plant Pathology Department
University of Tennessee-Knoxville
rakinrin@vols.utk.edu
Twitter: @roofusever

2. Course outline
1. Plant-parasitic nematodes
2. How plant-parasitic nematodes spread
3. Symptoms/indications of nematodes
4. Four important plant-parasitic nematodes
5. Management strategies for plant-parasitic nematodes
6. Chemical nematicides
7. Biological nematicides

3. Plant-parasitic nematodes
• Microscopic roundworms living in soils.
Over 4100 species are known. They have
different stages or forms
• The J2 have mouthpart known as stylet for
penetration and feeding. They can feed on
all plant types.
• May live inside plants or freely in the soil.
• Cause high damage and yield loss to crops.
• Most damaging in sandy soils
• Above-ground symptoms may be absent
or similar to other diseases. Diagnosed by
below-ground signs and soil sampling
Click For More Information
Plant parasitic nematode (a) eggs, (b) juveniles, (c) juveniles
penetrating plant root, (d) cysts of cyst nematode, and (e) needle-
like mouth part. Photo courtesy of TheSCNCOALITION.COM (a, c,&
d), UM (b), and UNL (e)

4. • Once in a field they cannot be eliminated. Their
spread within a field is aided by nematode
movement in soil along water drainage and in
dust during wind erosion and on farm equipment
• Between fields, spread is aided by movement of
infested plants, farm equipment, soil, irrigation
water and animals
• Cross-border spread is aided by transport of
infested produce, nursery plants, seeds, tubers, or
bulbs
How plant-parasitic nematodes spread

5. General or above ground symptoms
• Stunted growth
• Leaf yellowing
• Plant may wilt or die in severe case
• Patchy areas with stunted and
reduced plant stands often seen in
field
Severe stunting of soybean caused by nematode infestation.
Courtesy: Steve Koenning
Yellowing and death of plants infected with
root-knot nematode. Courtesy: Edward Sikora,
AU.
A corn field with patchy area caused by
sting nematode. Courtesy: Tamra Jackson-
Ziems, UNL

6. Four important nematodes
● Root-knot nematodes – Meloidogygne spp.
● Cyst nematodes – Heterodera spp. and Globodera spp.
● Lesion nematodes – Pratylenchus spp.
● Reniform nematodes – Rotylenchulus spp.
6

7. Root-knot
nematodes
● Most important plant-pathogenic nematodes. Have
worldwide distribution, wide host range, and
comprises of over 100 species.
● Meloidogyne incognita, M. hapla, M. javanica, and M.
arenaria are the most damaging species.
● Hatched juveniles of the root-knot nematode attack
root tips of host plants, invade the root tissue, and
cause galls or knots to form on the roots
● Economically important crop hosts include soybean,
cotton, corn, sorghum, vegetables, fruits, etc.
7
Galls on okra. Photo courtesy of
Rebecca Melanson, MSU
Gall on tomato root. Photo
courtesy of Penn State PPEM

8. Cyst nematodes
● These are Heterodera and Globodera nematode genera.
They are the second most damaging nematodes and
found worldwide. They form cyst on their host plants
● Soybean cyst (SCN), potato cyst (PCN), sugarbeet cyst,
and cereal cyst nematodes are the most important cyst
nematodes.
● SCN causes more than $1.5 billion in yield loss annually
in the U.S, and yield loss due to PCN may range from 50
to 80%
● Cyst nematodes will mature on their hosts in 3-4 weeks.
The cyst is the dead female body with eggs 8
Heterodera glycines cysts on
soybean
Globodera cysts on potato tuber.
Photo courtesy of Florida Division of
Plant Industry.

9. Lesion nematodes
● Migratory nematodes feed mainly on their
host root cortex, which will result in the
formation of necrotic lesion on the roots
● There are over 70 species of lesion
nematodes worldwide, and their host range
comprises of more than 400 plant species
● Lesion nematode damage on hosts can
result in ~85% crop yield loss
9
Lesion
nematode
Pratylenchus sp.
Photo by Sean Kelly, DAFWA

10. Reniform nematodes
● Among the most damaging nematodes. It is difficult
to detect because it does not form galls or cysts on
its host.
● Overwinter as egg masses on root surfaces or
immature adults free in soil. Females become
reniform or kidney-shaped after they invade a root
● Have wide host range including weeds and important
crops such as soybean, cotton, pineapple,
sweetpotato, and cassava.
● Cause root necrosis that may result in root pruning
and dwarfing 10
Reniform nematode
Rotylenchulus sp.
Photo courtesy of C. Clark,
APS: CABI Bioscience

11. 11
Integrated management
strategies
1. Prevention practices
2. Soil sampling
3. Soil solarization
4. Soil biofumigation
5. Crop rotation
6. Resistant varieties
7. Nematicides

12. 12
• Making sure that plant-parasitic nematodes
are not introduced to new fields
• Disinfest or treat planting materials
including seeds, seedlings, tubers and
bulbs before planting
• Disinfest or clean all farm tools and
equipments before use on a new farm
• Work from non-infested to infested fields to
reduce the chance of contamination
1. Preventive practices

13. 13
• Sampling is done prior planting to determine types
and densities of nematodes in a field to aid
nematodes management decisions.
• Use a 1-inch diameter probe (image 1) to pull soil
from 6 to 8 inches depth. Gather about 20-cores
samples across 20-acres area in a zig-zag pattern
(image 2).
• Mix all the soil cores together to form a single
sample (image 3). Send a subsample (image 4) to
an appropriate soil lab for analysis.
• Base management decision on the test results
2. Soil sampling
1 2
4
3
Click for More Information

14. 14
Nematodes population densities
and potential damage thresholds
for soybean
Nematode Nematode per 100 cc soil/damage threshold
Low Moderate High
Root-knot 0 - 8 10 - 32 34+
Soybean cyst- juveniles
(J2)
0-10 20-50 60+
Soybean cyst - eggs 200 - 2000 2000 - 5000 5000+
Lesion 0 - 18 20 - 58 60+
Stunt 0 - 58 58 - 198 200+
Spiral 0 - 198 200+ ---
Lance 0 - 58 58 - 98 100+
Ring 0 - 38 40 - 138 140+
Stubby root 0 - 16 18+ ---
Sting 0 2 4+
Dagger 0 - 18 20 - 58 60+
For More Information
--- = no threshold level for this category

15. 15
• Covering/mulching of wet soil with
transparent plastic film (50-200 µm thick) for
4 to 8 weeks to inactivate soil nematodes
• Requires high solar incidence to allow lethal
temperatures to be reached
• Also used to kill other soilborne pests
including insects and weeds, while increasing
populations of beneficial bacteria
• Can be applied to just nematode-infested
areas in a field to minimize cost of plastic
3. Soil solarization
Click for More Information

16. 16
• Incorporation of organic materials such as
Brassica species and manures to soil to
decompose and release toxic volatile gases that
can suppress or kill soilborne pathogens
including nematodes
• Field must be irrigated to field capacity before
incorporation to facilitate intense microbial
decomposition of the incorporated materials
• Vaporization of the volatile gases can be
prevented by covering the soil with transparent
plastic after incorporation
4. Soil biofumigation
YouTube Video on Biofumigation

17. 17
• Planting of non-host or poor host crops in
nematode-infested field to lower
nematode population density
• The knowledge of the density of other
nematodes that may be present in the
field is needed to make proper choice of
rotation crop
• A crop that is a nonhost or poor host for
one nematode may be a host for another
5. Crop rotation
Example of how crop rotation can be designed for a field
infested with soybean cyst nematode

18. 18
Host and suggested (poor or non-
host ) rotation crops for
nematodes
Nematod
e
Host crops/not
recommended
Rotation (poor or non-host)
crops
Root-
knot
Soybean, corn, cotton,
vegetable crops
(watermelon, tomato, sweet
potato, etc.)
Grain sorghum, peanut, rice
Soybean
Cyst
Soybean, Green beans Grain sorghum, corn, cotton,
peanut, rice
Lesion Soybean, corn, grain
sorghum, peanut
Rice, cotton
Reniform Soybean, cotton, vegetables grain sorghum, corn, peanut, rice
For More Information

19. 19
• Planting of nematode-resistant crop
varieties to reduce nematode population
density and avoid yield loss
• Select varieties with resistance to many
types of nematodes
• Continuous use of the same type of
resistant variety can cause resistance
and management to fail
• Always include a susceptible or tolerant
host in rotation
6. Resistant varieties
This Demo shows how nematode can overcome resistance.
Susceptible – stunted - (left), and resistant – healthy looking –
soybean plants grown in nematode infested plots.
Photo credit UMN

20. 20
• Are chemical or biological
products used to kill or inhibit
nematode activities.
• Are used when multiple
nematode infestations occur; or
• When no resistant variety or
non-host crop is available
7. Nematicides
Left image: showing the destructive effect of a chemical
nematicide on nematode cyst. Right image: showing
fungal hyphae arresting nematode activity

21. 21
Chemical nematicides
• Volatile organic compounds that
have broad-spectrum toxic activity
to nematodes and other soilborne
organisms
• They are mostly applied to soil
before the crop is planted
• They are very effective but can be
toxic to humans and environments
Fumigants

22. 22
Chemical nematicides
• Nonvolatile toxins. Have broad spectrum
activity. They are applied before, during,
or after planting
• Applied through soil drench, drip
irrigation, or spray onto foliage. They act
by contact or by systemic action
• Requires water to disperse within soil.
May be less effective compared to
fumigant chemical, and can also leach
Non-Fumigants

23. 23
Examples of chemical
nematicides
Fumigant
• Telone II
• Vapam HL
Non-fumigant
• Vydate
• Nimitz
• Velum Prime
Caution:
Most chemical products are toxic to humans, animals, and environments. They are to be
used only when other management options are not available or cannot help. Use of these
chemical may require special training or use certification to be used safely.

24. 24
Telone II
• A multi-purpose liquid soil fumigant for controlling
plant parasitic nematodes and other soilborne
organisms in soils to be planted to vegetable crops,
field crops, fruit and nut crops, and nursery crops.
• The active ingredient (1,3 dichloropropene (1,3-D)) is
very toxic, and is to be used only by Certified
Applicators. Telone II should only be used in open
fields, not in a greenhouse
• Used as a preplant liquid soil treatment applied by soil
injection. Effectiveness depends on temperature and
soil moisture
Click for More
Information
Fumigant

25. 25
Vapam HL
• A multi-purpose liquid soil fumigant. Active ingredient
is Sodium methyldithiocarbamate.
• It is a Restricted Use Pesticide, so can only be used by
a Certified Pesticide Applicator in the United States
• Kills plant parasitic nematodes, other soilborne
pathogens and weeds in soils to be planted with row
crop, vegetable, potato, berry, and orchard crops.
• Can be used alone or in combination with Telone® or
chloropicrin. Used as a preplant soil treatment by drip
or sprinkler chemigation, soil injection and soil
incorporation with bedding equipment.
Click for More Information
Fumigant

26. 26
Vydate
More information
HERE
• A non-fumigant nematicide. Active ingredient, oxamyl. It
kills both plant nematodes and insects. It’s a restricted-use
pesticide due to high toxicity towards nontarget organisms
• It’s a systemic nematicide. It can move through plant parts
on contact with the root or leaf. It can kill nematodes inside
the plant
• Available in liquid form, and can be applied before, during,
or after planting by soil drench, in-furrow, drip injection,
broadcast, or foliar spray
• It is effective on carrots, cucumbers, tomatoes, eggplants,
squash, peppers, watermelon, and cantaloupes
Non-fumigant

27. 27
Click for More Information
Nimitz
• A non-fumigant nematicide, active ingredient is
fluensulfone, and is effective against several types of
plant nematodes. It’s a reduced-risk pesticides
• Has systemic activity - it can move through foliage
parts to root part to kill nematodes inside plant, but
foliage application not recommended to avoid
phytotoxicity
• Most effective when used preplant. Application is by
in-furrow or through chemigation at planting
• Effective on fruits and many vegetable crops including
cucumbers, tomatoes, eggplants, and peppers
Non-fumigant

28. 28
Velum Prime
• A non-fumigant nematicide. The active ingredient is
Fluopyram, which is effective against several types of
plant nematodes.
• Velum prime is a systemic fungicide that has nematicide
activity and is less toxic
• Application is by in-furrow, soil drench at planting or
through chemigation at planting
• It is labeled for use on cotton, potatoes, cucurbits,
watermelons, and cantaloupes; fruiting vegetables such
as tomatoes, eggplants, etc.
Click for More
Information
Non-fumigant

29. 29
Biological nematicides
• Naturally occurring living organisms
or their products or plant extracts
used to kill or suppress nematode or
(and other soilborne pathogens)
activity
• Pose low or no toxic risk to humans,
animals, and environments
• They may come in liquid, powder, or
granular form. Applied through seed
treatment, dipping, drench, spray, or
drip irrigation method
Seed treatment
Dipping Drench
Drips Spray

30. 30
Examples of bio-
nematicides
Bacterial-based
• Aveo
• Biost Nematicide 100
• Clariva pn
Fungal-based
• BIOSTAT®
• BIO-ACT®/ MELOCON WG
Mixture (bacteria and fungi)
• Nemaxxion Biol
Plant-based
• Dazitol
• Nemakill
Disclaimer:
These products are reported because they are labeled for use against
plant-parasitic nematodes. We have no information about their efficacy.
Growers are advised to use their judgment when buying products

31. • Broad-spectrum nematode control activity. Offer
protection against all nematode problems on
corn and soybean
• Active ingredient: Bacillus amyloliquefaciens, an
endospore-forming bacteria species
• Application method: Seed treatments
Aveo
31
Click for More Information
Bacillus spp. Source Rufus
Akinrinlola, UTK
Bacterial-based

32. Biost Nematicide 100
32
Click for More
• Broad-spectrum protection, against soybean
cyst, root-knot, Reniform, sting and other
nematodes on soybean, corn and cotton
• Non-living active ingredient: Heat-killed
Burkholderia rinojenses and its fermentation
media
• Application method: It comes in liquid
formulation that is applied as seed treatments
Bacterial-based

33. 33
Clariva pn
Click for More
Information
• Narrow-spectrum nematode control activity. Offer protection against
sugarbeet cyst and soybean cyst nematode
• Active ingredient: Pasteuria nishizawae, an endospore-forming bacteria
species
• Application method: Seed treatments
Bacterial-based

34. 34
• Broad-spectrum protection.
• Controls root-knot, burrowing, cyst, root lesion,
stem, spiral, reniform, and dagger nematodes.
It’s label for use on fruits, vegetables, vine,
tubers, row and ornamental crops
• Active ingredient: A biotype of the fungus
Purpureocillium lilacinum
• Works best when applied as a pre-plant
treatment, and can be utilized in both powder
and liquid form
Click for More Information
BIOSTAT MOA
 Parasitizes all reproductive stages of
plant pathogenic nematodes, eggs
and females.
 Deforms, destroys ovaries, and
reduces egg fertility.
 Under acidic pH, it produces toxins
that affect nematode’s nervous
system.
BIOSTAT®
Fungi-based

35. 35
• Broad-spectrum control against nematodes.
• Controls root-knot, cyst, root lesion, and sting
nematodes on fruits, vegetables, vine, tubers,
row and ornamental crops
• Active ingredient: The fungus Paecilomyces
lilacinus strain 251
• Used as a pre-plant, transplant or, when
needed, as a post-plant treatment, by
chemigation through drip or micro-sprinklers
Click for More Information
Bottom left photo – the fungus attacking a nematode egg.
Bottom right photo – the fungus killed adult Pratylenchus
nematode
Bio-Act/ Melocon WG
Fungi-based

36. 36
• Broad-spectrum control against
nematodes.
• Controls Root knot, Soybean cyst,
lesion, stem, dagger, and burrowing
nematodes
• Active ingredient: Consortium of
microorganisms (Bacillus subtilis,
Trichoderma spp., Paecilomyces spp.)
and extracts (Tagetes) Click for More Information
Nemaxxion Biol
Bacteria and fungi-based

37. 37
• Broad-spectrum, plant-based fumigants,
active against nematodes, insects, other
soilborne pathogens, and pre-emergent
weed seeds. Not label for cyst nematodes.
• Active ingredients are natural chemicals
(capsaicin and isothiocyanate) from chili and
mustard, which are biodegradable
• Used as a preplant soil treatment through
drip irrigation or by hand spray (small area)
Click for More Information
Dazitol
Plant-based

38. 38
• Broad-spectrum, organic nematicide, active
against nematodes, insects, and other
soilborne pathogens
• Active ingredients are cinnamon oil, clove
oil, and thyme oil. Does not leave toxic
residue.
• Application is by direct spray or through
drip irrigation. Can be applied as preplant,
at plant, or after planting treatment
Click for More Information
Nemakill
Plant-based