Download By resistant varieties

Control of economically
important disease of cereals
Presented by:Gaurav Kumar Pal
M.Sc.Applied Microbiology 3rd sem
Department of Microbiology
CCS University Meerut 250004
Introduction :•
•
•
1.
2.
3.
4.

Different types of cereals crops are affected by
various type of bacterial fungal &viral disease.
They damage the grains &straw yield of cereals
crops.
These cereals crops are –
Rice (Oryza sativa)
Wheat (Triticum spp.)
Maize (Zea mays )
Barley (Hordeum vulgare)
In these crops rice & wheat crops grown mostly.
Disease in Rice :BLAST Disease :Pathogen:-Pyricularia oryzae
Symptoms: Aerial parts of plant infected.
 Spindle shaped spots on
leaves.
 Centre is whitish grey spots
with brown margins.
Rice blast disease
Control : By resistant varieties
• Co 4,TKM-1,Co 29,IR-579,A-249,A-200,T-603,T-141 etc.
 By seed treatment
• immerse seed on 0.2% Solution of Kalimat B for 24 hrs.
 By spraying
• Spraying Bordeaux Mixture before & after the flowering of the crop.
 By proper manuring
• Should not used Nitrogen fertilizer in excess amount
&used potassic &phosphoric manure.
Brown spot (fungal blight)
 Pathogen :Helminthosporium oryzae
 Symptoms:• Development of dark brown
spots on the upper surface of
the leaf.
• Disease appears after
transplanting.
• Infected all parts of plant except
roots.
• Seed borne disease.
Brown spot disease
Control : By resistant varieties
•
CH-13,TI-41,T-2114,Bam-10,Nagra41-14,IET-13238,CR-8430 etc.
 By seed treatment
•
•
•
seed treatment with ceresan.
seed treatment with agrosan GN.
By hot water treatment 50-52°C for 10 minutes.
 By spraying
•
•
Spraying Bordeaux Mixture
Spraying dithane Z-78(organic sulfur compounds )
 By proper manuring
• Should not used Nitrogen fertilizer in excess amount.
• Level of nitrogen &phosphorus should be well balanced.
Bacterial blight : Pathogen :-Xanthomonas
oryzae
 Symptoms:•
•
•
•
•
•
Appearance of dull greenish water
soaked or yellowish spot on the tip
of leaf.
Bacteria induce wilting of plants.
Occurs within 3-4 weeks after
transplantation.
Lesions turn yellow to white as the
disease advances.
Severely infected leaves tend to
dry quickly.
Seed borne disease .
Seedling wilt by bacterial blight disease
Control: By field sanitation
•
removing weed hosts, rice straws.
 By resistant varieties
• IET- 9190,CR-316-636,RP 2151-165-3-1,RP 2151-21-22,etc.
 By seed treatment
•
•
Seed treatment with bleaching powder (100µg/ml) and zinc sulfate (2%)
reduce bacterial blight.
Soaking of seed for 8 hrs in ceresan.
 By spraying
•
Control of the disease with copper compounds, antibiotics and other
chemicals highly effective.
 By proper manuring
•
•
Proper application of fertilizer, especially nitrogen.
Proper plant spacing are recommended for the management of bacterial
leaf blight.
False smut disease
 Pathogen- Ustilaginoidea virens
 Symptoms• Individual rice grain transformed into a
mass of spores or yellow fruiting bodies.
• Growth of spores enclose floral parts.
• Immature spores are smooth, yellow, and
covered by a membrane.
• Growth of spores result to broken
membrane.
• Mature spores orange and turn yellowish
green or greenish black.
• Only few grains in a panicle are usually
infected.
Infected penicle
False smut control Crop rotation
• Effective against disease.
 Spraying
• At preflowering stages spraying of carbendazim fungicide and
copper base fungicide can effectively control the disease.
• Applying captan, captafol, fentin hydroxide, and mancozeb can
be inhibited conidial germination.
• Three spray of 0.4% Bordeaux mixture (when plants are about 3
months)
 Resistant varieties
•
Sabarmati, Saket-4,Sona,Surya,Vijaya,Jayanti,IR 22,IR 26,IR 28 etc.
 field sanitation
• Destruction of straw and stubble from infected plants is
recommended to reduce the disease.
Tungro disease of virus
 Pathogen :-rice tungro virus
 Symptoms:• discoloration begins from leaf tip and then
lower leaf portion.
• infected leaves may also show striped
appearance.
• reduced tillering
• delayed flowering, which may delay
maturity
• most panicles sterile or partially filled
grains and covered with dark brown
blotches.
 Control:• Use of resistant varieties
Tungro disease
Disease of wheat
 Rust Disease :
Earliest known disease of crop
plants

1.
2.
3.

Three different forms of rust attack
on wheat crops.
Black or stem rust (Puccinia
graminis tritici)
Leaf or Brown or orange rust
(Puccinia triticina Eriks.)
Yellow or stripe rust(Puccinia
striiformis)
Found in all over the world .
Rust disease
Black or stem rust disease
 Pathogen:- Puccinia graminis
tritici
 Symptoms:• Having large spore mass.
• Pustules are dark reddish brown.
• Occur on both sides of the
leaves, & stems & on spikes .
• The infection sites feel rough to
the touch.
Stem rust disease
Leaf rust disease
 Pathogen:- Puccinia triticina Eriks
 Symptoms:• Small brown pustules develop on
the leaf blades.
• They may group into patches in
serious cases.
• Infectious spores are transmitted via
the soil
• Reddish-orange urediospores
develop.
• rupture the epidermis of the leaf
surface as the spores mature.
Leaf rust disease
Yellow rust disease
 Pathogen:- Puccinia striiformis
 Symptoms:• Appearance of yellow-colored stripes
on each leaf blade.
• These yellow stripes are yellow
colored urediniospores.
• The disease usually occurs early in
the growth season, when
temperature ranges between 2 and
15°C.
• Weakened plants.
• loss in number of grains per spike
and grain weight.
Yellow rust disease
Control of rust disease
 By resistant varieties
• HD 2009,SONALIKA,WH 147,S 307,S 308,HW 741,WL 614,C 306
etc.
 By spraying
• Spraying nabam &zinc sulphate.
• Spraying dithane ,zineb,etc.
• Spraying actidione etc.
 By proper manuring
• Should not used Nitrogen fertilizer in excess amount.
• Rust resistance increased by the use of potassic manure.
 field sanitation
• Destruction of self shown plants is recommended to reduce the
disease.
 Cultivation of early maturing varieties
• early maturing escape from the attack of rust.
Loose Smut disease
 Pathogen:- Ustilago
nuda
 Symptoms:• Seed borne disease.
• Disease seen only on the
emergence of the ears.
• The black powder is seen
in the ear instead of
flowers.
• Masses of smut spores
replace the entire head of
plants.
Loose smut disease
Control of Loose Smut disease
 By resistant varieties
•

•
•

•
•
•
NP 710,NP 729,NP 823,MP 108,MP 144,MP 168,Bansi 224, etc.
Sanitation
Infected ears should be burned outside the field.
Spore is destroyed .
By seed treatment
By hot water treatment 50-52°C for 10 minutes.
By solar treatment
Clean seeds should be used.
 By chemical treatment
• Kept 40-50 hrs in 2%spergon or chlorose destroyed pathogen.
Karnal bunt disease
 Pathogen:-Tilletia indica
 Symptoms:• A few kernels per spike to be
affected by this disease.
• Diseased kernels can be easily
detected by visual inspection:
• A mass of black teliospores
replaces a portion of the
endosperm.
• Diseased kernels give off a
fishy odor when crushed.
Bunt disease in wheat grains
Healthy seed
2 % Infection
10 % Infection
30 % infection
50 % infection
100 % infection
Karnal bunt disease control
 By resistant varieties
• Kalyan sona,S 227,PV 18,HD 2012,4513,4519,IWP
72,87,127,129,WL885,1581 etc.
 By seed treatment
• By disinfesting seeds in a 1.5% solution of sodium
hypochlorite plus Tween 20 for 10 minutes
• Clean seeds should be used.
 By crop rotation
• Proved beneficial for disease control.
Powdery mildew disease
 Pathogen:-Blumeria graminis
sp. Tritici
 Symptoms:• White to pale gray, fuzzy or
powdery colonies of mycelia,
and conidia.
• Present on the upper surfaces
of leaves and leaf sheaths
(especially on lower leaves) ,
and sometimes on the spikes.
• Older fungal tissue is yellowish
gray.
• This superficial fungal material
can be rubbed off easily with
the fingers.
Control of Powdery mildew disease
 By resistant varieties
• NP 710,NP 718,E750,C 591,Sonora,Sonora HD 2204,hd
2074,VL 401,etc.
 By chemical treatment
• By using sulpher dusting .
 By crop rotation
• Proved beneficial for disease control.
By spraying
• Spray with 0.1% benlate
• Spray with 0.1%Karathane
Leaf blight disease
 Pathogen:-Alternaria triticina
 Symptoms:• Small, chlorotic, oval shaped lesions
appear.
• These lesions become irregular in
shape.
• The chlorotic borders of the lesions
may become diffuse and turn light to
dark brown in color.
• Lesions are difficult to distinguish
from spot.
• Infection usually starts on the lower
leaves, but symptoms can be found
on all plant parts.
Leaf blight disease
Control of Leaf blight disease
By resistant varieties
• NP 4,NP 52,NP 200,NP 809,NP 824 etc.
Sanitation
• Infected plants should be burned outside
the field.
By seed treatment
• By hot water treatment 50-52°C for 10
minutes.
• Clean seeds should be used.
Disease in maize
Head smut disease
Pathogen: Sphacelotheca reiliana
Symptoms :
the fungus penetrates the seedlings and
grows inside the plant without showing
symptoms,
Infection of the tassel also leads to reduced
pollen production.
Abnormal development of the tassels.
Masses of black spores in place of the
normal ear.
Control of disease :By sanitization
By crop rotation
By resistant varieties
Head smut disease
in corn
Brown spot disease :•
•
•
•
•
•
•
•
Pathogen:-Physoderma maydis
Symptoms :Occurs in areas of high rainfall
and high temperatures.
It attacks leaves, leaf sheaths,
stalks.
Symptoms develop on leaf blades
and consist of small chlorotic
spots.
Spots on the mid-ribs are circular
and dark brown, while lesions on
chlorotic spots.
Nodes and internodes also show
brown lesions.
 Control
 By field sanitation
 Resistant varieties
Brown spot disease in corn leaf
Ear rot disease
 Pathogen:Fusarium graminearum
Fusarium
moniliforme
 Symptoms:





Ear infection begins as white mycelium.
later turns reddish-pink, in infected kernels.
The fungus produces mycotoxins.
Infected kernels develop a cottony growth.
The fungus produces mycotoxins known as
fumonisins, which are harmful to several animal
species.
Ear rot disease in corn
Control of Ear rot disease
•
•
Resistance varieties
Cultivation of varieties that are resistant to ear rots is the most practical and
cost-effective means of ear rot management.
• Chemical control
•
•
•
Where the crop is infected systemically with Fusarium species,
application of fungicide early in the season can limit ear infection.
Management of insect pests (ear borers) will reduce infection of the ear
through injury sites caused by insect feeding.
• Proper storage
•
Storing grain at low moisture (below 15%) reduces the disease.
• Cultural control
•
Management of infected crop debris will reduce the amount of disease.
Reference
 Agrios, George N. ,Plant Pathology. 5th ed.
Burlington, MA: Elsevier Academic Press, 2005.
 Pandey b.p.,plant pathology pathogen &plant
disease(2010),page no (147-214).s.chand
&co.ltd new Delhi.
 http://www.knowledgebank.irri.org/RiceDoctor/in
dex.php/information-sheets-mainmenu-2730
 http://wheatdoctor.cimmyt.org/en/pests-adiseases/list/122?task=view
 http://en.wikipedia.org/wiki/Bright's_disease#Sy
mptoms.
 http://maizedoctor.cimmyt.org/en/pests-anddiseases/list/218