1. Management of
Plant parasitic
Nematodes

2. TOPICS :
 Introduction
 Methods
 Conclusion

3. INTRODUCTION OF NEMATODE
MANAGEMENT :
 Nematodes are omnipresent
 Transmitted through variety of methods.
 Irrigation water is the prime source infected
composts soil.
 Control methods is needed to raise crops
economically.

4. METHODS :
 Regulatory methods
 Cultural methods
 Physical methods
 Chemical methods
 Biological methods

5. Regulatory Method:
Quarantine / exclusion :
 This implies exclude the entry of a pest .
 Buy or grow transplants that are
nematode-free.
 Use nematode-free soil or potting medium.
 Clean tools and equipment when changing areas
or fields.
 Remove infected plant roots .

7. Cultural Control:
Crop Rotation :
 keeping nematode population under check especially when
there are distinct host preferences.
 Susceptible crops should be grown once in few years
 Rotating them with non-host crops.
 Vegetables should not be grown in same field repeatedly.
 Keep weeds in check.

8. Fallowing and Ploughing :
 Keeping the land fallow and deep ploughing reduce
nematodes e.g. root knots and others.
 Nematodes are sensitive to heat and drying action of the sun
and the wind.
 So in hot and dry condition fallowing and ploughing are best
remedy of nematodes control.

10. Use of Organic Amendments:
 Green manure compost, oil-cakes has been found to
Reduced Nematodes.
 These encourage the growth of natural enemies and
decomposition products
 Raising green crops also enhance development of some
predacious nematodes in soil.

11. Use of Resistant and Tolerant Varieties:
 The most practical and economical methods of controlling
nematodes.
 Multi-resistant strains of plants to nematodes has been made
 The main drawback sometimes is the development of
resistant breaking nematodes which makes the process futile.
 Resistance has been mainly to root-knot nematode.
Resistant and non resistant roots:

12. Flooding :
 Flooding can be adopted where there is an enormous
availability of water.
 Under submerged conditions, anaerobic condition, kills the
nematodes by asphyxiation.
 Chemicals lethal to nematodes such as hydrogen sulphide
and ammonia are released in flooded condition which kills
the nematodes.

13. Adjust planting time:
 Nematode life cycle depends on the climatic factors.
 Adjusting the time of planting helps to avoid nematode damage.
 In some cases crops may be planed in winter when soil
temperature is low ad at that time the nematodes cannot be
active at low temperature.
 Early potatoes and sugar beets grow in soil during cold season
and escapes cyst nematode damage.

14. Antagonistic crops:
 Certain crops like mustard, marigold and neem have chemicals
or alkaloids as root exudates which repel or suppress the plant
parasitic nematodes
 In marigold plants : α terthinyl and bithinyl compounds
 In mustard : allyl isothiocyanate
 Pangola grass: Pryrocaterchol
 Such enemy plants can be grown along with main crop or
included in crop rotation.

15. Trap cropping :
 Two crops are grown in the field, out of which one crops is highly
susceptible to the nematode.
 The nematode attacks the susceptible crop.
 By careful planning, the susceptible crop grown first and then
removed and burnt.
 Thus the main crop escapes from the nematode damage.
 Cowpea is highly susceptible crop can be grown first and then
removed and burnt. Cowpea is highly susceptible to root knot
nematode and the crop can be destroyed before the nematodes
mature.

16. Physical:
Heat treatment of soil :
 This is a general practice for soil sterilization against all
organisms harmful or beneficial.
 Nurseries use autoclaved soil [ 30 psi for 30 minutes] for
potting.
 In greenhouses steam is released through perforated pipes
running through the soil.
 Dry heating of soil by burning off the standing crop waste is
also practiced.

17. Hot water treatment of planting material :
 It is mainly used for transplanted crops, bulbs, rhizomes, root
stock and tubers.
 Usually dormant bulbs of ornamental plants and root stocks of
citrus are given this treatment.
 Hot water treatment of rice seed is a very effective method to
control white tip nematode which is transmitted through seed.

18. Solarization :
 This method involves covering moist soil with polythene film
during period of intense sunlight and heat.
 This capture energy from sun thus bringing change in
physical ,biological and chemical changes in soil.
 The soil temperature increased is lethal to many of soil borne
nematodes.
 It increase soil fertility by increasing availability of nitrogen
and other essential nutrients.
 This method of nematode management is very useful where
heat from sun rays is sufficient.
 It only reduce nematode population , but not enough to finish
all nematodes.

19. Dry heat:
 Dry heat also reduce nematodes population.
 Nematodes egg and their juvenile stages are usually killed if
they are exposed to dry heat.
Use of oils :
 Spraying 15% water soluble oil reduces infestation by
nematodes.
 Many of oils also used also reduce the counts of eco-parasitic
nematodes.
 By this spraying nematodes movement sis restricted and
quantity becomes low

20. Exposure to direct sunlight:
 Spread infested layer of soil in thin layers up to few cm on soil.
 Exposed layer to sunlight for 10 days in summer to eliminate
nematodes that are present in soil layer .
 This practice is useful for preparing soil mixtures for
ornamentals and nursery beds.
Irradiation :
 It is an effective means to kill nematodes though it is non-
feasible and non-practical.
 UV rays used are lethal to nematodes.
 Many other radioactive rays are used in this management
technique.

21. Osmotic pressure :
 Addition of dextrose or sucrose to nematode infested soil is
detrimental to nematodes.
 This reduce or restrict nematodes production or population.
 Although this method is non-economical and non-practical.
Floatation of seed :
 This is done in order for removal of nematode galls from seed
material and floatation.
 Flooding and floating of seeds are done to control nematodes
population.
 Seed also cleaned by mechanical cleaners to kill gall
nematodes.

23. Chemical control
Fumigants :
 These are first to identify as control in plant parasitic
nematodes.
 They may be applied to the soils as liquids, emulsions or
granules but the active ingredient spreads in the soil in the form
of a gas.
 These are applied as pre-plant treatments mostly.
 It is essential that the soil be treated is well prepared to a seed
bed condition.
 Soil moisture is moderate , uniform and the soil temperatures
should between 15 to 30oC at the time of application.

24. Commonly used fumigants :
DD
EBD MBr
DBCPCS2

25. APPLICATION:
 DD and EBD are highly phytotoxic and are applied 3 to 4
weeks before planting.
 DBCP can however can be used with irrigation water around
the roots of plants as recommended.
 DBCP mostly used as pre –planting .
 It is mostly used on perennials (citrus root nematode).

26. Non-fumigants/nematicides:
 These are applied to living plants parts and as pre –plant
treatments to annual crop.
 These are applied in granular form.
 These are applied during or shortly after planting to wet soils.
 It is important to have their application along irrigation water in
order to have proper dispersal through out soil surface.
 Some of nematocidal are insecticidal thus providing early insect
control.
 These are classified as carbamates and organo-phosphates.
 These compounds control many soil and foliar feeding
nematodes.

27. non fumigants fumigants
 Less phytotoxic
 Applied during planting
and post planting
 Greater residual
activity
 Effective at lower
dosages
 Control both soil and
foliar nematodes
 Somehow phototoxic
 Applied before
planting usually
 Less residual activity
 Not effective at lower
dosages
 Control only soil
nematodes

28. Nematicides : Used against :
Dichlorofenthion First used for management of root knot
nematode on turf and ornamentals.
Thionozin Used against as sting nematodes in
maize and root knot in vegetables.
(1957)
parathion Used against A.fragarie (1948)
Dazomet Used against root knot and lesion
nematodes (1957)
phorate Used against many nematodes as
stunt, root lesion etc.
fensulphothion Used against turf nematodes
phenamiphos Used against root knot and bare root
dip in citrus.
Commonly used nematodes :

29. Nematicides Used against :
Ethoprop Used against root knot nematodes
affecting tobacco ,tomato and also
against other.
Aldicrab Used against tobacco cyst nematode
carbofuran Used against many nematodes as
heterodera, Globodera.
oxyamyl Used against many nematodes.

30. Experimental compounds :
 Some compounds also posses nematicidal activity for
nematodes control.
They are :
 Amino acids
 Antibiotics (KT-199)
 Lavamisol
 Aldoxycrab
 Formaldehyde urea
 Sodium azide
 Avermectins
 Binapacryl phenols

31. Biological control.

32. Characteristics :
 Host specific
 Parasitism is always lethal
 Easily manipulated in laboratory
 Can be mass produced Easily disseminated with
standard equipment
 Potential for establishment & recycling
 Provides control for extended period
 Not harmful to environment
 Shelf-life of at least one year
 No hyperparasites
 Compatibility with others

33. Predators of nematodes:
 Important predators of plant parasitic
nematodes are mites , insects ,enchytrieds
and migratory nematodes.

34. Parasite of nematodes:
 Bacteria and some fungi are major parasites
of plant parasitic nematodes.
 Several fungi are isolated that parasitizes the
nematode.
 Fungi act as opportunistic .
 No virus still documented to harm nematodes.

35. Use of nematophagus fungi
 It is parasite .
 These forms trap usually.
 Several species of soil-dwelling fungi produce traps to
ensnare nematodes before they infect them.
 Traps come in many forms: adhesive hyphae,
networks, knobs, rings, and constricting rings.
 Some trapping fungi can proliferate in soil in the
absence of nematodes while others are more
dependent on nematodes as a nutrient source for
growth.
 As Arthrobotrys oligospora parasitic fungi

36. ENDOPARASITic ENDOZOIC
FUNGI
 These fungi produce either simple or flagellate adhesive spores
which upon contacting a nematode quickly and firmly attached to
its cuticle.
 It then germinates and enter the nematode body through germ
tube.
 Simple spore are ingested by nematode, reach the esophagus /
buccal cavity where they germinate e.g.. Harposporium
anguillulae
 While sticky spores stick to the nematode body & germinate and
penetrate directly through the nematode cuticle, produce
infective hyphae e.g. Meria coniospora & Nematoctonus bisporus
.
 Nematodes get restricted nutrients and ultimately weakens.

37. Parasitic fungus (zoosporic)
 Zoospores are motile spores that are propelled by
one or two flagella.
 When zoospores locate a host, they attach to the
nematode cuticle, often near a body opening
(mouth, anus, vulva), shed their flagellum, and
become sedentary (i.e., encyst).
 The encysted zoospores infect the nematode
cuticle by forming a penetration tube that enters
through an orifice or directly penetrates the
nematode cuticle.

38. Continue…
 When the resources within the infected nematode are
exhausted, the hyphae differentiate to form sporangia.
 Zoospores are produced within the sporangia and enter
the soil via an exit or discharge tube which is formed
when the spores are mature.
 Zoospore-forming fungi are believed to be
opportunistic parasites of vermiform nematodes,
attacking or colonizing weakened or dead nematodes.
 As Catenaria anguillulae

39. Egg parasitic fungus :
 There are a large number of fungi that can
parasitize nematode eggs, and the sedentary
juveniles and females of cyst and root-knot
nematodes.
 These fungi categorized in two groups.
 One is obligate parasitic fungi those that can grow
only in nematodes.
 Second is facultative parasitic fungi that can grow
to some extent in nematodes as well as on
organic matter in the soil.

40. Toxic chemicals released:
 The filamentous fungi have been widely studied for
their effectiveness in controlling nematodes.
 The mechanisms involved in this is direct through
antibiosis and parasitism.
 Trichoderma grows around the target and releases
toxic compounds and different lytic enzymes mainly
chitinases , glucanases and proteases.
 These proteins facilitate Trichoderma penetration into
the nematode and the utilization of the nematode
components for nutrition.
 The role of these lytic enzymes has been proved in
nematode control.

41. Bacteria:
 Some of them are endospore-forming actinomycetes that
are parasites of nematodes.
 Some rhizosphere-inhabiting bacteria are antagonistic to
plant-parasitic nematodes.
 Some bacteria inhibit nematode egg hatch and/or
penetration of roots.
 Mechanism involved Production of antibiotics that kill
nematode eggs.
 Degradation of the root exudates that the nematode relies
on for host location and to stimulate egg hatch.

42. Mites :
 The soil mite Lasioseius subteraneus
Mesostigmata Ascidae are an aggressive
predator of nematodes that colonizes
greenhouse cultures of root-knot nematodes.
 This mite has a generation time of less than 1
week at 28 ºC and can lay up to 18 eggs per
day when feeding on nematodes and kill them
.

43. Management Summary :
 No single practice will control nematodes, so
two or more control methods must be used.