Nematode pest of rice

a description about different types of nematode attack in the rice field (mainly rainy season rice) and their management

1. Nematode Pest
of Rice

2. Nematode Pest of Rice
Nematode infecting rice in aerial part
Rice stem nematode/ufra nematode (Ditylenchus
angustus)
White tip nematode (Aphelenchoides besseyi)

Nematode infecting rice in root region
Rice root-knot nematode (Meloidogyne graminicola)
Rice root nematode (Hirschmanniella spp)
Cyst nematode (Heterodera spp)
Sheath nematode (Hemicriconemoides spp)
Lance nematode (Hoplolaimus spp)
Root lesion nematode (Pratylenchus spp)
Spiral nematode (Helicotylenchus spp)

3. Root-knot disease of rice
Causal organism : Meloidogyne graminicola (Sedentary
endoparasite)
Disease reported from-Kerala, MP, Assam, West Bengal
and Tripura
Also reported –Bangladesh, Laos, Thailand, USA &
Vietnam
Yield loss
Av. Yield loss :10-20%
Severe cases loss: 50%
In India ,losses in grain yield have been estimated to be
16-32%

4. Symptom
Above ground symptoms
Chlorosis of leaves
Reduction in growth of the plant and number
of tillers
Patchy growth of the plant
Drying of leaf tip
Delay in flowering by 10-15 days

5. Below ground symptoms
Formation of galls at the tip of the root is the
diagnostic symptom
Reduction in root growth
Presence of egg masses on galled root

9. Management
Crop rotation with non-host crop viz.
groundnut, sweet potato, maize, soyabean
inhibit the development of M. graminicola
Soil amendment –rice husk, rice polish,
mustard oil cake, DCTW & neemcake
Soil treatment of nursery bed & main field by
carbofuran
Seed soaking with 0.1% carbosulfan for 12 hrs
Resistant varieties: TKM 6, Patnai, Monohar
Sali, Udaya

10. Ufra disease of rice
Causal organism: Ditylenchus angustus
(Rice stem nematode)
Butler (1913) 1
st
reported D. angustus from
Bangladesh
In 1919, Butler described the disease as
Dakpora
It is distributed in India, Bangladesh, Vietnam,
Burma & SE Asian countries

11. Yield loss:
Yield loss due to rice stem nematode may vary
from year to year depending on variety, time
of infection, degree of infection and the
environmental condition during crop season
Overall loss has been estimated 20-90% with
an avg. loss of 30%
100% loss in endemic areas
10-15% in W.B

12. Nature of damage:
Rice stem nematode feed ectoparasitically
on the primordia of tillers and suck the
cell sap of tender growing tissues.
They enter between the folded leaves and
sheath. Feeding on developing
inflorescence

13. Symptoms
At early stage, minute dots are found due to
sucking of chlorophyll by the nematode and is
known as splash pattern
In advance stage of the disease the chlorotic
portion becomes brown to dark in colour
Twisting & crinkling of young leaves and
margin of the leaves become corrugated
Many branches grow from the infested node
which give a bushy appearance of the plant.
The panicles may remain enclose within the
flag leaf sheath or may emerge partially or fully
from it

14. On the basis of rate of emergence of panicle the
symptoms are classified as-
Ufra-I: Panicles fails to emerge and completely
enclosed within the flag leaf sheath.
Ufra-II: Panicles partially emerges and bear
unfilled grains.
Ufra-III: Panicles emerge completely but all the
grains are chaffy. Sometimes panicle bears
normal grain only at the tip of the panicle.

18. MANAGEMENT: -
Burning of diseased stubbles and straw after
harvesting reduce ufra infestation
Crop rotation with non-host crop like jute, mustard
in ufra infested field
Summer ploughing helps nematode to destroy by
desiccation in the scorching heat of sun
Growing early maturing variety like Padmapani
Growing of resistant varieties- Rayada(selection).
Rayada 16-06 found to be resistant. Rayada 16-05,
Rayada 16-07, Rayada 16-08, Rayada 16-09 and
Bazail 65 as moderately resistant
Soil application of carbofuran 3G@ 1kg a.i/ha

19. White tip Disease of rice
Causal organism: Aphelenchoides besseyi
Dastur (1936) recorded white tip disease in
central provinces of India.
Yield Loss:
Sterile grain: 69.5%
Grain weight reduction: 65.4%
Av. yield loss: 10-30%

20. Nature of Damage: The white tip nematode
feed ectoparasitically on tender cells of leaf
blades, sheath and on the ovary, lemma and
palea and glumes

21. Symptoms
Withering or whip like whitish appearance of leaf from tip
downwards upto 2-5 cm
Crinkling and distortion of flag leaf enclosing the panicle
Reduction in size of panicle, number of grain and size of
the grain
The glumes of the infected spikelets remain white and do
not undergo any change either in shape or in size
The nematode reside on the inner side of lemma and palea
feed externally on the lodicules and ovary leading to
shriveled and empty grain
Abnormal development of floral parts observed

24. Management of white tip
disease
Burning of the infected stubbles prevents
carryover of nematode to next season.
Hot-water treatment of grains at 51-56
0
C for
10-15 min.
Use of resistant var- Krishna, Kaveri, IR-50,
Bala, TKM-9, Rohini, Ratna, Vijoya, IET-228
etc.
Spraying foliage with 0.1% carbosulfan
Soil application of carbofuran 1kg a.i/ha

25. Rice Root Nematode
Rice Root nematode, Hirschmanniella spp are the
most common nematode sp. Inhabiting
In India besides H. oryzae two other sp. Viz. H.
gracilis and H. mucronata are also important
Host: Weeds belonging to families Graminae and
Cyperaceae
Yield Loss:
Assam: 5.58-20.4%
Asian and African countries: 10-36%
Ave.: 25%

26. Distribution: Rice Root nematode widely distributed in
rice growing areas of India, Indonesia, Japan, Vietnum,
Malayasia, Srilanka, Thailand, Philippines, Bangladesh,
USA, Canada, Netherland, Germany, Newzealand, Cuba,
Ivorycost and Venezuala
Nature of Damage:
Nematode penetration leads to necrosis of the epidermal
cells results in extensive
Thickening of wall of the affected cortical cells and
dissolution of cell walls lead to formation of cavities in
the cortex
Intra cellular migration and feeding causes cell necrosis in
cortex and pericycle

27. Plant Symptoms:
Above ground symptoms are similar with nutrient
deficiency
Reduction in number of tillers, stunted growth of
plants, chlorosis, reduction of number of panicle
and grain weight. Affected plants have narrow and
thin clums
Delay in flowering by 10-15 days
Root invaded by Hirchmanniella sp are
characterized by yellowish to rusty brown
discolouration of cortical tissue
Severe damage results in degradation of cortex and
disruption of vascular element

28. Management
Sun drying of seed- 6hrs for 4 days
Summer fallow and ploughing the field can effectively
reduce nematode population
Crop rotation with jute, wheat, potato or blackgram leads
to drastic reduction in nematode population.
Keeping the field free from weeds during off season check
the buildup of nematode population
Application of mustard oil cake and neem cake @ 750-
1500 kg/ha
Nursery treatment with carbofuran @ 1kg a.i/ha
Root dip treatment with carbosulfan @ 0.2% for 6 hrs
significantly reduce nematode population
Seed soaking with carbosulfan for 6 hrs.