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 :-

• 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 –1. Rice (Oryza sativa)2. Wheat (Triticum spp.)3. Maize (Zea mays )4. 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 Three different forms of rust attack

on wheat crops.

1. Black or stem rust (Puccinia graminis tritici)

2. Leaf or Brown or orange rust (Puccinia triticina Eriks.)

3. 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 diseasePathogen: Sphacelotheca reilianaSymptoms :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

• 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 :-

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/index.php/information-sheets-mainmenu-2730

http://wheatdoctor.cimmyt.org/en/pests-a-diseases/list/122?task=view

http://en.wikipedia.org/wiki/Bright's_disease#Symptoms.

http://maizedoctor.cimmyt.org/en/pests-and-diseases/list/218