Introduction to the Integrative
Management of Plant-parasitic
Nematodes
Amy Peetz
Zasada Lab
USDA-ARS Horticultural Crops Research Unit
Corvallis, Oregon
Nematode Facts
• Roundworms
• Aquatic
• Most abundant multicellular organism on the planet - > 80,000
described species
• Vary from 82 µm
(.003 inches) to 8 m (26 ft) in size
• Occupy many ecological niches
Major Groups of Nematodes
Plant-parasitic
Nematodes
10%
Animal
Nematodes
15%
Free-living
Nematodes
25%
Marine
Nematodes
50% e.cleansing.com
Management of plant-parasitic nematodes
Bio-cultural management: - crop rotation/non-host covers
- antagonistic cover crops
- biofumigation (gm, vfa’s)
- solarization
- biocontrol agents
- organic nematicides
Chemical - fumigation
- postplant nematicides
Cultural management:
soil health / suppressiveness
enhancement?
minimize population buildup,
enhance crop resilience
water & nutrient management
Genetic resistance/tolerance
Limited utility
for perennials
“When using management practices
other than soil fumigation, growers
will need a basic knowledge of
nematode biology (host range, life
cycle, survival strategies) and access
to resources such as nematode
identification services” Annu. Rev. Phytopathol. 2010. 48:311–28
Presentation Outline
1. Plant Parasitic Nematodes i. Economic impact
ii. Parasitism
2. The Big Three in the Pacific Northwest
i. Meloidogyne hapla (root knot nematode)
ii. Pratylenchus penetrans (root lesion nematode)
iii. Xiphinema americanum complex (dagger nematode)
3. Overview of old and new nematode management practices
4. Integrated nematode management scenarios
a. Dagger nematode in grape
b. Root-knot nematode in vegetables
c. Ring nematode in tree fruits
3. Conclusions
Economic Impact?
Crop % Loss $ Loss
Banana 19.7 178 Million
Citrus 14.2 4 Billion
Cotton 10.7 2 Billion
Coffee 15.0 2 Billion
Potato 12.2 16 Billion
Rice 6.9 588 Million
Soybean 10.6 2 Billion
$100 BILLION/year worldwide loss, 8 BILLION/year in the
USA!
How Plant-parasitic Nematodes
Cause Plant Damage
• Direct damage
• Removal of host tissue
• Alter host physiology
• Allow 2 infection by another organism
• Transmit other pathogens
• Interact with other pathogens – synergistic
• Increase susceptibility of host to environmental stress
How Do Plant-parasitic Nematodes
Feed?
All plant-parasitic nematodes
have a protrusible spear
Stylet
How Plant-parasitic Nematodes
Cause Plant Damage
• Direct damage
• Allow 2 infection by another organism
• Transmit other pathogens
• Interact with other pathogens – synergistic
• Removal of host tissue
• Alter host physiology
• Increase susceptibility of host to environmental stress
Agriculturally Important Nematodes in
the Pacific Northwest
• Meloidogyne hapla
• Pratylenchus penetrans
• Xiphinema americanum
species complex
Meloidogyne spp. (Root-knot) # 1 nematode pest, 1000’s of known hosts!!
BIG 4
Meloidogyne incognita (cotton)
Meloidogyne arenaria (peanut)
Meloidogyne javanica (southern)
Meloidogyne hapla (northern)
Sedentary, endoparasite
Plant Response
Develop a specialized feeding-site within
the host root (giant cell)
Root-knot nematode
female
Feeding-site
Damage
Most common
nematode pest of turf
http://www.usga.org
http://southeastfarmpress.com www.agric.wa.gov.au
Strategies for Control
Prevention: Do not move nematode
Resistance: Mi gene
Cultural: Soil solarization
Biological: Antagonistic fungi and bacteria
Pratylenchus spp. (Root Lesion Nematode)
Migratory, endoparasite
No distinct infective or survival stage
http://www.apsnet.org
http://www.ipm.iastate.edu
Distributed worldwide Host independent life cycle
Most species have wide host ranges
Control Monitoring: Determine if and where a problem
exists
Cultural: Non-host rotation and cover crops
Chemical: Nematicides
Damage
• Feeding produces knobby, stunted roots
• May transmit or vector Nepovirus species
NePo-
Nematode vectored
Polyhedral
Tobacco Ringspot
Virus Damage
Grape Fanleaf Virus Damage
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to nonhosts
– Cover crops
– fallow
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to nonhosts
– Cover crops
– fallow
H. Ferris
• Only certified material free of nematodes should be planted
• Applies to all plant-parasitic nematodes
• Selection of planting material should be based upon knowledge
of nematodes present at the site (pre-plant nematode sampling)
Prevention – Certified Clean Planting
Material
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to nonhosts
– Cover crops
– fallow
H. Ferris
• Methyl bromide – EPA phaseout
• Common soil fumigants
• 1,3-Dicholoropropone – discontinued in Canada
• 1,3-D is the 6th most abundantly used pesticide in the U.S.
• Metam sodium
• Metam potassium
• Chloropicrin
“This fact is still made quite clear from a review of recent
field research trials conducted in Florida that shows that no
single, equivalent replacement (chemical or nonchemical)
currently exists that exactly matches the broad spectrum
efficacy of methyl bromide.” – J. Noling
Chemical:
Pre-plant Soil Fumigation-Narrowing Options
Fumigant Molecular
weight
Density
at 20 °C
Boiling
point
Vapor
pressure at 20
°C
Solubility in
water at 20
°C
g mol-1 g ml-1 °C mm Hg % w/w
Methyl
bromide
95 3.97 4 1420 1.34
Chloropicin 164 1.66 112 18 0.20
1,3-D 111 1.21 104 34 0.22
Metam
sodium
73 1.21 119 21 0.76
Courtesy Husein Ajwa
Fumigant Properties
Nema-Q (extract of Quilaja saponaria) BWE1000 (extract of Jugulans spp.) Promax (thyme oil) Neem products
Lannate (methomyl) Vydate (oxamyl) Cordon/Inline (1,3-dichloropropene) Enzone (Na tetrathiocarbonate) Abemectin
Plant-derived products
Plant growth products
“Traditional” nematicides
Root Power Bioforge Stimulate Plus
“Soft” chemistries
Multiguard (furfural) MCW2 (fluoroalkenyl) Movento (spirotetramat)
Fungal-derived products DiTera (M. verrucaria) Melocon (P. lilacinus)
Chemical: Post-plant Nematicides
Nematicide 7 Days 14 Days
Fosthiazate* 10 d 9 d
Nemacur* 43 c 88 abc
Vydate* 52 bc 68 bc
MCW2 67 abc 111 abc
Multiguard 130 a 128 ab
Nema-Q (5,000 PPM) 82 abc 107 abc
Nema-Q (10,000 PPM) 72 abc 57 c
Root Feed 104 ab 132 abc
BWE 1000 108 abc 124 ab
Cordon* (300 PPM) 110 a 101 abc
Cordon* (600 PPM) 56 bc 24 cd
Lannate* 120 ab 84 bc
Root Power 105 ab 130 ab
Control 119 a 168 a
Means are the average of 16 observations. P < 0.05
Photo by J. Gigot
No. Pratylenchus penetrans Recovered
Post-plant Nematicide Evaluations
Walters et al., HortTechnology. 2009. 19(4)
*Hard chemistry only treatment to produce
significantly different results from the non
treated control.
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to nonhosts
– Cover crops
– fallow
Genotype
M.
inco
gn
ita
M.
java
nic
a
M.
ch
itw
oo
di
M.
ha
pla
Xip
hin
em
a
ind
ex
Xip
hin
em
a
am
eria
ca
nu
m
Me
so
crico
nem
a
xe
no
pla
x
Pra
tyle
nch
us
vu
lnu
s
101-14Mgt R S S MR
1103Paulsen S S MS
110Richter R S S S
140Ruggeri S S S
1613Couderc R R S MR S S MS
3309Couderc S S R MS S S S
420A S R MS
Dog Ridge R R R S MR S
Freedom R R S? R R MS MS MS
Harmony R R S R MS S S S
Ramsey R R S? R MR S S MS
Riparia Gloire R R S MR Courtesy
Howard Ferris
Planting Material – Example: Grape Rootstocks
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to nonhosts
– Cover crops
– fallow
H. Ferris
Biocontrol
• The use of fungi, bacteria, viruses, other nematodes, to manage
nematodes. The are many examples of biocontrol of nematodes,
however, very few work in the field.
Bacterium - endospore forming Pasteuria penetrans
Fungus - adhesive rings by Arthrobotrys spp.
Management
• Monitoring
• Prevention
• Chemical
• Resistance
• Biological control
• Cultural controls
– Rotation to non hosts
– Cover crops
– Fallow
• Cover crops
• Amendments
• Biofumigation
• Non-host rotations
• Soil solarization
• Biological control
Marigolds Sudangrass
Small grains Mustards
Cultural Control
Integrated Management – Scenario 1
Xiphinema americanum (Dagger Nematode)
- Grape
Fallow/Tillage
Cover
Crop
Fumigation
Resistance
Cover
Crop
Fumigation
Resistance
K-strategist • Long lived
• Low repropuction rate
• Low motility
Fallow/Tillage
Integrated Management – Scenario 1
Xiphinema americanum (Dagger Nematode)
- Grape
Fallow/Tillage
Cover
Crop
Fumigation
Resistance
K-strategist
Brassica cover
crops
- Biofumigation
- Good weed
control essential
Integrated Management – Scenario 1
Xiphinema americanum (Dagger Nematode)
- Grape
Fallow/Tillage
Cover
Crop
Fumigation
Resistance
K-strategist
Brassica cover
crops
- biofumigation
- Good weed
control essential
Integrated Management – Scenario 1
Xiphinema americanum (Dagger Nematode)
- Grape
Fallow/Tillage
Cover
Crop
Fumigation
Resistance
K-strategist
Brassica cover
crops
- biofumigation
- Good weed
control essential
Few (no) breeding
programs actively
looking for
resistance to X.
americanum
Integrated Management – Scenario 1 Xiphinema americanum (Dagger Nematode)
- Grape
Meloidogyne hapla (Northern Root-knot Nematode)
- Veggies
Seed Treatment
Resistance Cover crop
Grafting
Integrated Management – Scenario 2
Seed Treatment
Resistance Cover crop
Grafting
Wide host
range including
weeds
http://plpnemweb.ucdavis.edu/nemaplex/Nemabase2010/NematodeHostRangeQuery.aspx
Integrated Management – Scenario 2
Meloidogyne hapla (Northern Root-knot Nematode)
- Veggies
Seed Treatment
Cover crop
Grafting
Resistance Be aware of the
species of root-
knot nematode
present
Integrated Management – Scenario 2
Meloidogyne hapla (Northern Root-knot Nematode)
- Veggies
Cover crop
Grafting
Resistance Be aware of the
species of root-
knot nematode
present
Seed Treatment
Bayer Cropscience
Integrated Management – Scenario 2
Meloidogyne hapla (Northern Root-knot Nematode)
- Veggies
Cover crop
Grafting
Resistance
Be aware of the
species of root-
knot nematode
present
Seed Treatment
Bayer Cropscience
Javelinseeds.com
Integrated Management – Scenario 2 Meloidogyne hapla (Northern Root-knot Nematode)
- Veggies
Mesocriconema (Ring Nematode)
– Tree Fruits
Resistance
Fumigation Orchard management
Cover
Crop
Integrated Management – Scenario 3
Resistance
Fumigation
Narrow host
range, mostly
woody
perennials
Orchard management
Cover
Crop
Integrated Management – Scenario 3
Mesocriconema (Ring Nematode)
– Tree Fruits
Resistance
Narrow host
range, mostly
woody
perennials
Fumigation Orchard management
Cover
Crop
Integrated Management – Scenario 3
Mesocriconema (Ring Nematode)
– Tree Fruits
Cover crop Narrow host
range, mostly
woody
perennials
Fumigation
Resistance
Partial
tolerance in
Lovell
rootstock
Orchard management
Integrated Management – Scenario 3 Mesocriconema (Ring Nematode)
– Tree Fruits
Narrow host
range, mostly
woody
perennials
Fumigation
Resistance
Minimize
nematode
impact by not
stressing trees
Orchard management
Cover
Crop
Integrated Management – Scenario 3
Mesocriconema (Ring Nematode)
– Tree Fruits
Conclusions
• Nematode management in the future will require more
information about nematode biology
• No “one size fits all” nematode management option exists
• Multiple nematode species may occur in a field –
balancing act
• Combination of management practices will be required
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