Foliar Nematode Problem Of Crops In West BengalAnd Its Management

Speaker: Puspendu Samanta M. Sc(Ag) 3rd Semester

Bidhan Chandra Krishi Viswavidyalaya

Department of Agril. Entomology

Mohanpur, Nadia, West Bengal

2016

Seminar Leader : Prof. S.K Mandal

Course no-ENT-591 Master’s Seminar-I 04/04/2016

Chairman: Dr. Kusal Roy

Foliar nematodes are the plant parasitic nematodes of the genera   Aphelenchoides, Ditylenchus, Anguina and Subanguina, Nothanguina etc.

Important nematode species under the genus Aphelenchoides are A.besseyi, A. ritzemabosi and A. fragariae

Ditylenchus angustus is an important causal agent of ‘ufra’ disease of rice. Anguina tritici is also an important nematode causing ‘ear cockle’ disease of wheat

Foliar nematodes, Aphelenchoides spp. are serious problem for the rice, onion, strawberry, flowering and ornamental crops. It is a severe problem to nursery industry. Yield loss due to Aphelenchoides besseyi in rice is varied from 30-50%

INTODUCTION

Aphelenchoides besseyi was reported as a serious pest of tuberose and found widespread in all the tuberose growing areas of West Bengal in greenhouse, open field, nurseries and landscape

Mukhopadhyay et al., (2010) identified five blocks of North 24 Parganas

and one block of South 24 Parganas districts, as hot spots for the A. besseyi with frequency of occurrence of 14-82%

Stem nematode, Ditylenchus angustus is a potential pest of rice in Assam and West Bengal

Occurrence of A. bassyei on onion was also reported for the first time from

West Bengal in India (Roy et al., 2011).

Fig-Ditylenchus angustusFig-Aphenlenchoides besseyi

Images of Foliar Nematodes

Host Foliar nematodes

Rice Aphelenchoides besseyiDitylenchus angustus

Tuberose

A.besseyi

Onion A.besseyi

Gladiolus A.bessyei

Crops Affected by Foliar Nematodes in West Bengal

DISTRIBUTION

Aphelenchoides besseyi on Rice

As early as 1915, this nematode

was reported to cause ‘white tip

disease’ of rice in Japan. At present

A. besseyi is a predominant feature

in Andhra Pradesh, Uttar Pradesh,

Madhya Pradesh, Chattishgarh,

Gujarat, Orissa and West Bengal.

Ditylenchus angustus on Rice

D. angustus was first found and reported from northern India on deepwater rice and early observations reported 50% yield losses of rice in Uttar Pradesh. It occurs in 20-80% of rice in West Bengal (Chakrabarti et al., 1985).

In India, rice yield losses have been estimated to range from 10 to 15% in West Bengal and 30% in Assam. There are also individual reports of it occurring in the Philippines, Indonesia, Pakistan, Madagascar, Malaysia, Egypt and Sudan

Aphelenchoides besseyi on Tuberose

It causes ‘Floral Malady’ in tuberose (Polianthes tuberosa L.).

A. besseyi on tuberose was first reported by Holtzman in 1968 from Hawaii and subsequently from Ranaghat area of West Bengal by Chakraborti and Ghosh (1993).

Now they are widespread in major tuberose growing areas of West Bengal and Orissa.

Aphelenchoides besseyi on Onion

A roving survey carried out during 2009 revealed presence of

Aphelenchoides besseyi in onion in Nadia and Hooghly district of

West Bengal (Roy et al., 2011).

However, occurrence of A. besseyi on onion is the first report of its

kind from West Bengal in India.

It was also reported to cause yield loss of onion to the extent of

18.7 % in Sri Lanka. It is more abundant in rice-tuberose cultivation

system in the state like West Bengal.

Aphelenchoides besseyi on Gladiolus

Gladiolus sp. cv. ‘Red Majesty’ was found naturally infected with A. besseyi during January, 2009 at the Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India (Roy et al., 2010).

A huge number of nematodes were isolated from the infected leaves of Gladiolus; subsequently they were identified as A. besseyi.

This is the first record of infestation of A. besseyi on Gladiolus in the world.

BIOLOGY

The generation time of Aphelenchoides from egg to adult is

finished in 10-14 days, with eggs hatching in 3 to 4 days, and

nematodes maturing after 6-12 days.

This rapid generation time allows populations to quickly

grow, sometimes reaching thousands of nematodes per leaf.

One generation time of D.angustus from egg to egg is finished

in 8 days.

Symptoms

General Symptoms of Foliar Nematode

Yellow, brown to purple to black wet-looking areas on leaves.

Angular, yellow areas on the leaf bounded by the veins of the leaf.

General yellowing, reddening, or bronzing of leaves.

Death of leaves that remain attached to the plant.

Cupping and distortion of leaves.

Small, sunken areas on the undersides of leaves.

Stunting of the entire plant.

Chlorosis similar to iron deficiency.

A. besseyi on rice Due to infestation of A. besseyi is commonly

known as ‘white tip disease’ of rice because of characteristic whitening of the top 3-5 cm of the leaf tips.

Leaf lesion later become necrotic accompanied with a crinkling and distortion of the flag leaf enclosing the panicle

White tip or whip like malformation of the top one-third of the leaf blade, chaffiness and abnormal elongation of glumes in some spikelets are most common symptom

Courtesy: AICRP on Nematodes

www.profirst.cn

D. angustus on rice D. angustus causing ‘ufra’ disease of rice.

During vegetative growth from seedling to flag leaf, the principal symptom of infection is leaf chlorosis.

D. angustus does feed on the inner surface

of the leaf sheaths, but these rarely show obvious symptoms.

In time the chlorotic areas will show some

localized browning. Depending on the severity of infection, chlorotic leaf areas, tillers or whole plants will wither and die, attaining a light-brown appearance.

Source: http:// www.knowledgebank-brri.org/ rice_disease.php

A. besseyi on Tuberose Ectoparasitic feeding of A. besseyi on the scape

(floral stalk) leads to the formation of prickle like rough, irregular structure. Scape becomes curled and twisted. Scapes of the infected plants are many times smaller than healthy and normal scapes.

Endoparasitic feeding of A. besseyi was observed in

leaves, bracts and tepals (petals) where brownish to black necrotic spots of varying shapes and sizes were developed. Often infected plant bears small sized twisted flowers. Sometimes inflorescence gets aborted completely.

Nematode may survive on bulb, leaves, scapes,

bracts, tepals and anthers but not in the soil. Courtesy: AICRP on Nematodes

A. besseyi on Onion

o Infected plants were observed with retarded growth having crinkling and twisting of stems and whitening of leaf tips. Later plants were discoloured, leaves were curled and hanging downward, bulbs were very tiny in size. Rotting of the bulbs was also noticed occasionally.

A. besseyi on Gladioluso Leaf symptom of infected Gladiolus begin with

elongated, vein-restricted, light brown to deep brown streak that become necrotic and black subsequently

o Infected leaves later on die and abscise. Floral stalk of the infected plant become shortened with less number of florets as compared to healthier ones. Corms of the infected plants are undersized and shrivelled. (Roy et al., 2010).

A

Source: Roy et al., 2010

Source: Roy et al., 2011

Management of Rice White tip Nematode:

• Preventive measures

Soak the seeds in water for 24 hours, later hot water treatment at 51-

53 degree centigrade for 15 minutes

• Chemical control:

Apply carbofuran 3G @33kg or phorate 10G @ 12 kg or fipronil

0.3G @ 30kg per ha of nursery at 5 to 7 days before pulling the

seedlings for transplanting.

Management of stem nematode (D. angustus)

The Deep water Rice Management Project (Anon., 1987) listed control

measures which may be appropriate against D. angustus:

-thorough burning of crop residues to eliminate all infested stem terminals

-extending the overwintering period by delayed planting

-the use of shorter-duration cultivars

-The use of resistant cultivars, when they become available, should prove

to be the most effective measure.

Management of Tuberose Nematode: (Pramanik et al., 2012)

Fairly tolerant variety e.g. Prajwal and Sringar can be grown

Prevent spreading of irrigation water from infected field to healthy field.

Select healthy nematode free bulb for planting

Bulb Treatment: Hot water treatment of bulbs at 50-550C for 10-15 mins

Fifteen days after sprouting of bulb apply carbosulfan 25 EC @ 0.05% or

monocrotophos 36WSC @ 0.05% at 15 days interval 2-3 times. Proper spacing should be followed to prevent

Infected plants and inflorescence should be either burnt or buried into field.

Conclusion In West Bengal, infestation of foliar nematodes i.e. Aphelenchoides besseyi has become a potential threat to the tuberose crop though it has been invariably reported to infest rice, onion and gladiolus. As of now, there is no instance of infestation of Ditylecnhus angustus in rice crop (Anon., 2009). They are the pest of flooded or deep water rice cultivation system. Their absence in recent times may be due to shifting of flooded or deep water rice cultivation system into fishery. Identification of nematode infestation at early stage of infestation to advocate suitable management strategy is an integral part of foliar nematode management of crops. Use of resistant cultivars and hot water or nematicidal treatments of plant propagules are important preventive measures to defend the menacing infestation of A. besseyi. They are more abundant in rice-tuberose cultivation system in this region and in monocotyledonous plant in particular. Considering the host diversity of this nematode species, it may attack many more plants in the state with the passage of time. Hence, a close vigilance on their infestation is an urgent need of the day. Government and non-governmental institution should come forward to take initiative to carry forward the research work towards managing this quarantined nematode pest (Lehman, 2004) unless export of tuberose may be hampered in near future.