This document discusses ear cockle of wheat, caused by the nematode Anguina tritici. Key points: - A. tritici causes galls to form on wheat ears and seeds, shortening and distorting the ears. - Symptoms also include stunted, twisted leaves and enlarged stems. The nematode lives and reproduces within the seed galls. - It can interact with the bacterium Clavibacter tritici to cause yellow ear rot disease. Management includes using clean seed, crop rotation, hot water seed treatment, and nematicide application.

1. PRESENTED BY: SALU MAHARJAN
SARAD GIRI
SARASWATI TANDON
SAURAZ B.K.
SAURAV LUITEL
Ear cockle of wheat

2.  First reported in England in 1743 by Needham.
 First reported in Nepal in 1966 and caused considerable loss
in Rupendehi and Nawalparasi.
 The nematode is found in association with the yellow ear rot
(tundu disease) caused by bacterium Clavibacter tritici.
 Corynetotoxin produced with the association are toxic to
man and even death of cattle and sheep when such seed are
feed.

3. Causal agent: Auguina tritici
 Pathogen is large nematode about 3.2 mm long and
120micrometer in diameter.
 Host: specific to wheat
 Nematode lays eggs and produces all its juvenile stages
and adults in seed galls.

4. Anguina tritici

5. Symptoms
 Affects all growing stages.
 Infected seedlings are more or less severly stunted and
show characteristics rolling and twisting of the leaves.
 A rolled leaves often traps the next emerging leaf and
inflorescence within it and causes it to become bent or
badly distorted.
 Base of the stem are enlarged, bent and generally stunted.
 Plants show spreading nature and tents towards more
tillering.

6. Infected ears/kernels
 The affected ears are shorter and broader with very short or no
awns on the glumes.
 The affected ears are greener than the healthy ones, and galls shed
off the ear more readily than kernels.
 Diseased head may have one, few or all of its kernel turned into
nematode galls.
 Galls are shiny at first but turn brown or black as the head matures.
 Mature galls are hard, dark, rounded and shorter than normal
wheat kernels.

7. Disease cycle
 Seed gall nematode contains 1000 to 3000 larvae in a seed.
 Galls fallen to ground softens during warm, moist weather and release
infective second stage juveniles.
 The juveniles swim upward on the leaves through film of water and feed
ectoparasitically on leaves.
 When the inflorescence begins to form, the juveniles enter the flower
primordia and produce the third and fourth stage juvenile and adults.
 Each infected flower primodium becomes a seed gall and may contain 80 or
more adults.

12. Interaction with bacterium
Anguina tritici plus Clavibacter tritici = yellow ear rot
 Nematode acts as a vector.
 Initial symptoms are same.
 Low temperature and high humidity favors this
disease.
 Yellow slimy ooze from leaves, stem and ear heads.
 Upon maturity, turns brown.
 No grain formation.
 Ear heads may not emerge from boot leaf.

14. Management
 Use only healthy seed from healthy crop.
 Cleaning of contaminated seeds by sieving or floating in
water.
 Crop rotation for 2.3 yrs such as barley or oat.
 Hot water treatment of seed, first soaking seed in cold
water for 4-5 hours and treating at 54°C.
 Soil application of nematicides such as Nemaphos,
Aldicap@ 10 kg a.i/ha.
 Easy to eradicate both diseases easily.