Nematode management in protected cultivation describes about existing practices of farmers and scientific integrated nematode management techniques along with IIHR package of practices.

1. NEMATODE MANAGEMENT
IN PROTECTED
CULTIVATION

2. NEMATODES
• Nematodes are microscopic, worm-like animals but not true
micro-organisms as they have all the systems that higher
animals possess, except the skeletal, circulatory and respiratory
organs.
• They occur everywhere, except air.
• A handful of soil from anywhere has hundreds or even thousands
of nematodes

3. • The soil nematodes can be broadly classified into two groups –
the free-living (microbial feeders, saprophytic and predators) and
plant parasitic nematodes.
• Free-living nematodes inhabit all types of soils (being most
abundant in organic soils).
• Some of them play crucial role in organic matter recycling.
• The plant parasitic nematodes dominate in soils having
vegetation.

4. PPNS - PLANT PARASITIC NEMATODES

5. WHAT ACTUALLY NEMATODES DO
IN PLANTS?
1.The semi- endoparasitic and endoparasitic nematodes
are considered most harmful
2.They modify the conducting vessels (xylem and phloem
cells) of plant tissues.
3.They direct the flow of water and nutrients for their own
feeding
4.Thus partially blocking the flow of nutrition to plant
system.
5.Mostly, the feeder roots (fine branches) are destroyed
compared to the main roots

6. 6. This is a continuous process leading to undersized “bare
root system” devoid of fine rootlets
7. Consequently, the absorption of water and nutrients and
their translocation to shoots are adversely affected.
8. Being obligate parasites, PPNs rarely kill their host plants
9. Instead, the plants are rendered weak, stunted, and give a
pale appearance due to poor supply of nutrients.
10. However, they often pre-dispose plants to infection by
pathogenic fungi and bacteria, leading to mortality or excessive
damage.

7. LOSS DUE TO NEMATODES
• In India, on an average, a national loss of Rs. 21,068.73 millions
has been estimated due to plant parasitic nematodes.
• An overall average annual yield loss in major horticultural crops
due to nematodes goes up to 60% under protected cultivation.
• Crops grown throughout India are seriously infested with
nematodes such as Meloidogyne incognita, M. javanica (root-
knot nematodes) and Rotylenchulus reniformis (reniform
nematode).
• Nematode problems on all these crops under protected
conditions have assumed alarming proportions leading to huge
crop losses (up to 80%) in selected crops.

8. NEMATODES-
T H E S E R I O U S
P E S T S O F
P R OT E C T E D
C U LT I VAT I O N ! ! !

9. WHY?
• High day time temperature and relative humidity within the greenhouses
and low tunnels
• General poor plant hygienic conditions inside and outside the
greenhouses provide ideal conditions for the introduction and rapid
multiplication of insects, fungal, viral bacterial and diseases caused by
plant parasitic nematodes
• The proliferation rates of nematodes in poly house cultivation reached
up to 10 to 30 folds more than in the open field cultivation.
• The population build up is very rapid in the poly houses and nematode
population reaches 5 – 6 times of threshold levels within 18 - 24 months,
making the poly house cultivation a wasteful exercise.
(Hanafi & Papasolomontos, 1999; Greco & Esmenjaud, 2004).

10. PPNS
(1) Root‐knot nematodes (Meloidogyne spp.)
(2) Cyst nematodes (Heterodera and Globodera spp.)
(3) Root lesion nematodes (Pratylenchus spp.)
(4) Burrowing nematode (Radopholus similis)
(5) Reniform nematode (Rotylenchulus reniformis)
(6) Xiphinema index (the only virus vector nematode)
(7) Foliar nematode (Aphelenchoides fragariae, A. besseyi)
(8) Burrowing nematode (Radopholus similis)
(9) Bulb and stem nematode (Ditylenchus dipsaci)

11.  Polyhouse crops are confronted with all categories of
nematodes attacking roots
 Ectoparasites are invariably present and less damaging
 The focus is on endoparasites that are most damaging
 Generally, nematode distribution in open field conditions is
patchy; while in polyhouses, this is more or less uniform

12. IDENTIFYING NEMATODE
ATTACKED PLANTS
Most people judge if the plant gives a sick (pale/stunted)
appearance, their impression is deficiency of nutrition or
water stress
That is true, but this situation could be due to nematode
damage, as affected roots would not be able to uptake
nutrients even if available abundantly in soil
But many people do not uproot the plants to diagnose
symptoms on the roots
If only we uproot the sick plants and study the damage to
roots, at least some important nematode diseases can be
diagnosed.

13. SOURCES
Source of Nematode Infection
y Infested Soil- Yes
y Infected planting material- Yes, sometimes only
y Water- Sometimes Yes
y Air- No
y Seed- Sometimes Yes
Source of Nematode Spread
y Implements used in polyhouses
y Footwear of workers
y Agricultural machinery

14. NEMATODE
MANAGEMENT
IN PROTECTED
CULTIVATION
SYSTEMS

15. FARMERS’ PERCEPTIONS AND PRACTICES
 Many polyhouse growers are aware about nematode problems
 This is mainly because of the high value crops cultivated in
polyhouses where each and every plant is precious, remunerative
that farmers can ill-afford to lose
 They are ready to invest anything to protect their plants
 Higher literacy rates among polyhouse growers is another factor
for their concerns about nematode problems.
 Most farmers rely on pesticide dealers for nematode solutions,
rarely seeking expert advice

16. Given below is a gist of what farmers generally practice for nematode
management in polyhouses; along with expert comments to dispel their
perceptions.

18. NEMATODE MANAGEMENT–
SCIENTIFICALLY

19. Nematode management is largely
prophylactic or based on cultural and
biological methods. These have to be
initiated before planting / sowing time;
however, it is nearly impossible to
manage nematodes in standing crops.

20. 1. CONSTRUCTION OF NEW POLY HOUSE/NET HOUSE –
MANDATORY SOIL TESTING FOR NEMATODES
 Fields having a long history of vegetable cultivation should be
completely avoided.
 Fields under cereal crops usually may not harbour nematodes that
attack polyhouse crops.
 Ignorance of this particular precaution can lead to disastrous
nematode infections in the first crop itself.
 It is strongly recommended that soil samples collected from
proposed sites for the construction of new poly houses/net houses
be compulsorily tested for nematode infestation.

21. AVOID THE SITES FOR CONSTRUCTION OF
NEW POLY HOUSES WITH HISTORY OF
FOLLOWING CROPS
Major Root-Knot Nematode Susceptible Crops
1. Vegetable Crops: Tomato, Capsicum, Chilli, Brinjal, Carrot,
Lady’s Finger (‘Bhindi’), gourds, melons etc.
2. Fruit Crops: Papaya, Grapes, Pomegranate, Banana, Guava etc.
3. Pulses and Oilseed Crops: Pigeon pea, Chickpea, Greengram,
Blackgram, Groundnut etc.
4. Ornamental Crops: Gerbera, Carnation, Tuberose etc.

22. SAMPLING FOR NEMATODE DIAGNOSIS
Collection of soil samples for nematode assay from proposed
site of new poly house/ net house or just before planting a new
crop in the established poly house/net house
a) Remove 2-3 cm upper layer of the soil with the help of a
hand hoe (‘khurpi’/spade)
b) Collect about 50 grams (a handful) soil up to a depth of 15-
20 cm (subsample- Fig 1).
c) Collect 10-20 such subsamples from one-hectare area in a
zig-zag manner (Fig. 2) covering the whole field area.

23. d) Put all the subsamples in the same polythene bag
(composite sample); the total weight should not be less than
half kg and tie it with a rubber band. Keep the sample in
another polythene bag.
e) Write the sample details on a paper and keep it in between
inner and outer polythene bag.
f) Seal the outer bag; it is ready for dispatch to a nearest
nematology lab for assay.

25. 2. RAISING NEMATODE-FREE PLANTING
MATERIAL
• Seeds of varieties suitable for poly houses may be procured
from reliable dealers only.
• The seedlings must be raised only in soil-less media
• Prepared in clean and sterilized plastic trays (or washed
thoroughly with bleaching solution) by growers themselves, or
procured directly from designated nurseries.

26. Special care should be taken that the soil-less medium
should not come in contact with soil, and that the trays
should also be stacked on raised structures.

27. • No farm yard manure or vermicompost may be added in the
nursery medium in spite of the fact that soil media (cocopeat,
vermiculite or perlite) do not contain any nutrients for the
plant.
• Only water soluble fertilizers may be used.
• Irrigation of nursery trays should be done only with very clean
and algae-free water.

28. 3. MONITORING NEMATODE POPULATION IN
EXISTING POLY HOUSE/NET HOUSE
• It is always advisable to get the soil tested for nematodes before
planting a crop.
• Based on the nematode population in the soil at the time of planting a
new crop, it is possible to predict the likelihood of crop losses.
• Prepare the field as is normally done for new crop, collect the soil
sample and get it tested for nematodes.
• Based on the recommendations, follow the nematode management
protocols, if necessary.
• Even if the poly house/net house has no history of nematode infection,
the soil testing is always preferable.

29. 4. REMOVAL OF ROOTS FROM PREVIOUS CROP
• Roots harbour nematode eggs, and each root gall contains
hundreds of nematode eggs.
• Old galls coalesce that contain thousands of eggs inside.
• After the crop is over, in spite of pulling the plants along with
roots, some galls detach from the roots and the nematode
juveniles emerge from the leftover roots in the soil.
• These nematode juveniles are ready to infect the new crop.

30. • Therefore, it is strongly recommended that the roots of
previous crop should be removed as much as possible.
• Digging out the finer roots is most essential.
• Such removed roots should be piled in a heap outside, dried
and burnt (at a safe distance away from poly houses).
• This single practice can remove 80-90% of nematode
inoculum from the soil.

31. 5. SUMMER SOLARIZATION
• Every year, during peak summer (May-June), after the crop is
over and removal of leftover roots is complete, the field
should be ploughed thoroughly, leveled and watered lightly
just to dampen the soil.
• The soil surface should be covered with thin (25 µm)
transparent polythene sheet.
• The edges should be overlapped and sealed properly.

32. • The whole polyhouse should be sealed by dropping the
polythene curtains on all sides.
• Do not open the polyhouse for a minimum 2-3 weeks.
• This practice can coincide with preparation of nursery in the
meantime, besides preparing the multiplication of bio-agents
outside.
• Soil solarization singly is so effective that if done
meticulously, there may not be any necessity of using
chemical pesticides.

34. 6. ORGANIC AMENDMENTS FORTIFIED WITH
BIO-AGENTS
• Nematologists at IIHR, Bengaluru standardized successful
management strategies of nematodes and other disease
complex using bio-pesticides like Paecilomyces lilacinus,
Pochonia chlamydosporia, Trichoderma harzianum, T. viride
and Pseudomonas fluorescens.
• Farmers who adopted IIHR technology reduced the use of
agro- chemicals to 40 to 45% and obtained 30 to 35%
increased yields in capsicum, gerbera and carnations.

35. • Select a shady, cool and covered place for stacking well
rotten FYM or Vermicompost or both.
• One ton of FYM (one big tractor trolley) is sufficient for one-
acre poly house.
• Procure bio-control agents like Trichoderma harzianum or T.
viride and Pseudomonas fluorescens from a reliable source.
• The efficacy of bio-agents is important in terms of no. of
propagules (CFU-Colony Forming Units) present per cc/g in
the bio-agent culture being used for fortification of FYM.
• Trichoderma harzianum or T. viride should have a minimum
of 2x108 CFUs per cc, while P. fluorescens should contain
2x1012 CFU per cc.

36. PROCESS- ENRICHMENT OF FYM
• Sprinkle/pour the bio-agent on the heap of powdered FYM at the
rate of 2 kg/2 L per ton.
• This should be followed by thorough mixing of the bio-agent in
FYM.
• Moisten the heap by sprinkling water and fully cover it with
banana, coconut leaves or chaff that allows aeration.
• The FYM should not come in contact with soil, and well protected
from sunlight and rains.
• Mix the heap once in a week, followed by moistening and covering
again for 3-4 weeks, till the time solarization is going on and
seedlings are being raised in the nursery trays concomitantly.

37. STEPS INVOLVED IN FORTIFICATION /
ENRICHMENT OF FYM USING BIO-AGENTS

39. • Once the solarization process is over, remove the polythene sheets from
poly house, prepare the beds and mix the bio-agent fortified FYM
uniformly over the beds in top soil.
• The quantity would vary depending upon the overall nutrient status of
poly house soil.
• Trichoderma and Pseudomonas are general bio-agents that improve the
plant health and have broad spectrum activity, including against
nematodes.
• However, should there be specific nematode problems, bio-agents like
Purpureocillium lilacinum (Paecilomyces lilacinus) or
• Pochonia chlamydosporia can be procured and multiplied in the same
way in FYM using similar dosage levels as mentioned above.
• Neem cake powder @ 50-100 g/m2 of planting bed may be mixed on the
top layer about 7-10 days before seeding/transplanting.

40. PROCESS OF ENRICHMENT OF NEEM/
PONGAMIA/ MAHUA CAKE
• 1 ton of neem/ pongamia/ mahua cake has to be enriched by
mixing with 2 kg of each of Pseudomonas fluorescens +
Trichoderma harzianum + Paecilomyces lilacinus.
• It has to be covered with mulch and optimum moisture of 25 -
30% has to be maintained for a period of 15 days.
• Once in a week thoroughly mix the neem cake for maximum
multiplication and homogenous spread of the microorganisms
in the entire lot of neem cake.

42. PROCESS OF ENRICHMENT OF
VERMICOMPOST
• 1 ton of vermicompost has to be enriched by mixing with 2 kg
of each
• of Pseudomonas fluorescens + Trichoderma harzianum +
Paecilomyces lilacinus.
• It has to be covered with mulch and optimum moisture of 25 -
30% has to be maintained for a period of 15 days.
• Once in a week thoroughly mix the vermicompost for
maximum multiplication and homogenous spread of the
microorganisms in the entire lot of vermicompost.

44. 7. CROP ROTATION AND ANTAGONISTIC
CROP
• Crops which invite nematode problems must be rotated with
some other non- host crops.
• Once nematode problem inside poly house is identified, the
immediate next crop must be changed.
• Also antagonistic crop like Marigold can be planted randomly
in beds to reduce nematode infestation.
• Antagonists Crotolaria juncea (Green manure) crop can be
raised and incorporated into soil before cropping.

45. • Asparagus, pangola grass, neem, castor bean, and marigold
produce substances in their roots that are toxic to at least one
or more kinds of nematodes.
• Marigolds are known to be particularly effective against root-
knot nematode.
• Marigold roots release the chemical alpha-terthienyl

46. 8. CHEMICAL NEMATICIDES
• We suggest that chemical application may be done only when
absolutely necessary, under conditions of very high initial
nematode population.
• Carbofuran is a granular nematicide that can be applied in
soil at the time of seeding/transplanting @ 1-2 kg a.i./ha.
• However, carbofuran does not give the desired result for long
durations under polyhouse conditions as the nematodes tend
to rebuild their population within 2-3 months of its use.

47. • Soil fumigation can be made by the use of Methyl Bromide, but it is
banned.
• So Metham Sodium, Basamid, Dazomet and Cador are used now.
• Oxamyl, fenamiphos, cadusafos and ethoprop are the most
popular nonfumigant nematicides.
• The post plant application of oxamyl was useful after preplant
application of 1,3 D/metham sodium under black polythene mulch.
• Metham sodium was applied by drip and 1,3D along with
Chloropicrin were applied one month before planting significantly
reduces nematode population.
• In view of long-pending demands, several pesticide companies
have developed products based on chemicals like fluopyram,
fluensulfone etc. having nematicidal properties.

48. SOIL
FUMIGATION
Step 4 Spread Basamid uniformly on the surface
of beds at the rate of 30 g/m2
Step 3 After one week prepare beds with friable
crumb structure.
Step 2 Irrigate and leave for one week to activate
soil organisms and weed seeds
Step 1 Prepare soil to fine tilth

49. Step 9 Conduct germination test in soil. If germination is normal,
undertake planting.
Step 8 Leave open the bed for 2-3 days to allow the escape of toxic
gases
Step 7 After 5 days, remove plothene and loosen soil to 15 cm depth
with any implement
Step 6 Cover soil with polythene sheet and prevent escape of active
gases. Seal the margins.
Step 5 Press the bed with heavy rollers or drums

51. 9. GENERAL SANITATION IN AND AROUND
GREENHOUSE
• A strict routine of removal of weeds in and around polyhouses
should be followed as they provide safety against during the
off-season.
• Apart from crop rotation inside the greenhouse, cultivation of
nematode susceptible crops should be avoided in the vicinity
of greenhouses.

52. 10. GRAFTING WITH RESISTANT ROOT
STOCKS
• Plants are joined together so that they grow as one plant
• The below ground portion of the plant i.e., ‘rootstock’ is chosen for its
ability to resist or tolerate soil-borne diseases or abiotic stresses and the
above-ground portion ‘scion’ is taken based on its agronomic traits.
• Major advantages of grafting include disease or nematode resistance,
stress tolerance or increased productivity.
• Nematode resistant root-stocks claimed by some private nurseries may
be confirmed with experts before adoption.

53. 11. SOIL-LESS CULTIVATION
• Soil-less cultivation is a process of growing plants (without
soil) in water containing dissolved nutrients, especially
practised in greenhouses with specialized structures having
controlled environment.
• It is free from weeds, nematodes and soil-borne diseases due
to aseptic processing.
• It is an advanced and capital intensive method.
• Coco- peat is widely used

54. Soil-less cultures fall into three general categories:
• i) Solid substrate culture: where different media, all without soil
are used.
• ii) Hydroponics: In this system, plants are supported in water
soluble nutrient media
• iii) Aeroponics: In this system, plant roots are suspended in
controlled condition chambers and supplied soluble nutrient
media through sprays, atomization etc.

56. PACKAGE OF PRACTICES GIVEN BY
IIHR
• Land should be thoroughly ploughed and soil should be
brought to fine tilth.
• Before preparation of the beds in the poly-house, incorporate
20 tons of FYM enriched with the bio-pesticides in the soil.
• Raised beds made with size according to the requirement and
the type of crop.
• Add recommended doses of fertilizers. Also add carbofuran or
phorate @ 50g/sq.m + 200g neem/ pongamia/ mahua cake
enriched by bio-pesticides per sq. m.

57. • Further incorporate bio-pesticide enriched FYM@ 2kg/sq. m
or biopesticides enriched vermicompost @ 500g/sq.m in top
18 cm of soil in the beds.
• Water the beds for 7-10 days for proper decomposition of
these organic materials.
• It is possible that farmers would not have prepared beds
initially as mentioned above and they observe the infestation
of nematodes, soil borne pathogenic fungi and bacteria on the
crops.
• Then the following steps for the management of nematodes,
soil borne pathogenic fungi and bacteria need to be taken.

58. APPLICATION OF THE BIO-PESTICIDES TO
A STANDING CROP- IIHR
Step 1: Soil application:
• Apply 100 g of neem / pongamia / mahua cake or 250 g of
vermicompost enriched with Pseudomonas fluorescens +
Trichoderma harzianum + Paecilomyces lilacinus on 1 sq. m.
beds or around the rhizosphere of the plants.

59. Step 2: Spraying:
• The organic formulation containing Pseudomonas fluorescens
and Trichoderma harzianum has to be sprayed on the plants
at regular intervals of 20 days at a dosage of 5g/ lit or 5ml/ lit.
• Alternately, take 20 kg of neem/ pongamia/ mahua cake
enriched in the above mentioned manner and mix it in 200
litres of water, leave it for a period of 2-3 days.
• Filter this suspension and use it for spraying by mixing 250ml
of suspension in 1 lit. of water at regular interval of 20 days.

60. Step 3: Drenching or application through drip irrigation system:
• The IIHR patented organic formulation has to be given
through drip/ by drenching @ 5g/ lit or 5ml/ lit. at regular
interval of 20 days.
• Alternately, take 20 kg of neem/ pongamia/ mahua cake
enriched in the above mentioned manner and mix it in 200
litres of water, leave it for a period of 2-3 days.
• Filter this suspension and use it for drenching at regular
interval of 20 days.
By following all these methods farmers can get significant increase
in the yield of the crops and the cost benefit ratio will be above 1: 3.

61. NEMATODES IN COMMERCIAL
CUT FLOWERS WITH
MANAGEMENT

62. ROSE
• Root knot nematode( Meloidogyne incognita):
– Formation of Root galls
– Symptom of malnutrition, reduced shoot growth, chlorotic leaves
• Management:
– Deep summer ploughing, soil fumigation with Dichlorvos
– Application of Nemagon (10-12 l/ha) along with irrigation

65. • Root lesion nematode (Pratylenchus vulnus and Pratylenchus
penetrans):
– Cause root decay
– Stuntung of growth
– Chlorotic leaves
• Management:
– Application of Nemagon
– Soil fumigation with Dichlorovos or Carbon disulphide

67. GERBERA
 M. incognita infection makes the plants highly susceptible for
the attack of Fusarium oxsporum f.sp. dianthi.
 Phytophthora parasitica + M. incognita interact to produce a
disease complex in gerbera leading to reduction in the yield
around 40 to 60 %.
 Management same as in rose.

69. CARNATION
• Carnation is a host to about 21 nematodes
• The most important ones are Cricomemoides curvatum,
Cricomemoides xeroplex and Meloidogyne incognita.
• Nematodes cause reduced root system, stunted shoot growth
and reduction in the number of blooms
• Nematodes can be eliminated by growing plants in fumigated
soil
• Application of Furadon. Aldicarp or nemaphos@ 10g/m2 can
control nematodes.

71. FOLIAR NEMATODE (Aphelenchoides besseyi) IN
TUBEROSE
• Infected flower stalk initially appears
rough, stalk becomes crinkled, stunted
and finally distorted and in severe cases
flower buds failed to bloom.
• Brown streaks appear on leaf bracts and
petals and subsequently develop into
rusty brown spots.
• The severely infected flower stalk
becomes rotten and brittle over drying,
even gets blind and the number of
flowers per stalk is also reduced.

72. NEMATODE MANAGEMENT APPROACHES
IN TUBEROSE:
• Pre- soaking of tuberose bulbs in plain water or in neem-seed-kernel-extract (NSKE
4%) for overnight followed by dipping in monocrotophos 36SL at 500-700ppm for 4-6
hours.
• After sprouting, three to four sprayings with monocrotophos 36SL at 500ppm at 15 to
20 days interval is needed.
• In the second and third year crop, same spraying for 3-4 times with monocrotophos
36SL at 500ppm at 15 to 20 days interval should start from April-May onward to reduce
the nematode infestation.
• Field sanitation is most essential for reducing infestation. Infested plant parts should be
burnt or buried into the soil.
• Grow nematode tolerant tuberose cultivars, Prajwal and Shringar(Khan & Ghosh,
2007)
• Growing tuberose away from rice field is encouraged to avoid contamination of

73. CHRYSANTHEMUM
• Meloidoyne incognita- Root knot nematode
• Pratylechus penetrans- Root lesion nematode
• Aphelenchoides ritzemabosi- Foliar/ leaf nematode
Control:
Use pasteurized or fumigated soil for nursery and main field
Use nematode free planting material
Sterilise soil before planting
Maintain proper sanitation
Apply carbofuran or phorate @ 50 g/sq. m.
Follow IIHR package of practices

75. CROSSANDRA

76. PLANT PARASITIC NEMATODES ASSOCIATED WITH SOME IMPORTANT
COMMERCIAL FLOWERS
Nibedita Borgohain(Journal of Biosciences, India- 2016)
• In India, highly valued commercial flowers such as asiatic lily,
carnation, chrysanthemum, gerbera, gladiolus rose, tuberose
etc.
• Among various nematodes identified the most devastating
nematode genera affecting flowers are Meloidogyne,
Aphelenchoides, Ditylenchus, and Pratylenchus.

77. ROOT KNOT NEMATODE IN FLOWER
CROPS

78. Foliar nematode Aphelenchoides spp.:
• Foliar nematodes are one of the most important nematode
pests which attack ornamental plants, especially
chrysanthemum. These nematodes attack leaves, buds and
other soft above ground plant parts rather than roots in
temperate regions of the world and is always highly damaging
in wet and cool seasons.
PLANT PARASITIC NEMATODES ASSOCIATED WITH
SOME IMPORTANT COMMERCIAL FLOWERS:

79. SYMPTOMS:
a. Initial symptom is a chlorotic linear lesion, which latter
become brown or necrotic.
b. Most characteristic symptom of the nematode infestation is
the vein –limited necrotic symptom.
c. Curling, twisting and stunted growth of newly emerge stems.
d. Affected tissue turns pale green, then yellow and eventually
brown.

83. ROOT-KNOT NEMATODE Meloidogyne spp
:
• It is a major disease in most of ornamental crops grown in India.
• The use of infested planting materials is a important source of spread of this disease
in the subcontinent.
SYMPTOMS:
• a. Generally infected plants show stunted growth and yellowing and chlorosis of
foliage.
• b. On underground parts, gall and necrosis develops especially in chrysanthemum and
carnation
• c. In tuberose the symptoms are exemplified by stunting, yellowing and drying up of
leaves and rotting of bulbs.
• d. In gladiolus heavy root galling can be seen accompanied by yellowing of leaves
which subsequently lead to stunted growth.
• e. Infected gerbera plants show the symptom of tip drying leading to die back.

85. BURROWING NEMATODE
Radopholus similis:
SYMPTOMS:
• a. Radopholus similis cause extensive decay of root and
rhizomes, stunting and chlorosis and eventually decline of
plant.
• b. The infected plant show reduced number and size of
flowers and shorth=ened the productive life of planting

91. THANK YOU