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MANAGEMENT OF PLANT BACTERIAL DISEASES –

CULTURAL,MECHANICAL AND BIOLOGICAL

Course teacher :Dr. Meena Asst. Professor

Course associate :Dr.John son Asst. Professor

Department of plant pathology CPPS , TNAU , CBE -3

Submitted by

RAMALINGAM.K

2015601510

PAT 603 Plant Bacteriology (2+1)

Select the disease free propagation materials:

Tubers – Ring rot of potato (clavibacter michiganenses subsp.

Sepedonicum).

Seeds - Block rot of cabbage (xanthomonas campestris pv

campestris),

Rhizomes – Moko wilt of banana (Ralstonia solanacearum),

Bud woods - canker and gummosis of stone fruits caused by

pseudomonas syringae pv.syringae and citrus variegated

chlorosis caused by xanthomonas fastidiosa.

Bud chips and setts – Ratoon stunting disease sugarcane

caused by Leifsonia xyli.

Seed certification: The seed certification programes to raise pathogen free seeds.

E.g. cabbage block rot (Xanthmonas campestris pv. Campestris). Internally Seed borne disease.

Bean bacterial blight –(Xanthomonas phaseoli) seed borne and soil borne disease

Eradication of infected plants or plant parts:

Pruning and burning

Examples:

Citrus canker caused by xanthomonas axonopodis pv.citri. Apple fire blight bacterium (Erwinia amylovora),

Cutting should be done about 30 cm below the point of

visible infection.

The tools should be disinfested - soaked in 10%

commercial sodium hypochlorite solution or flame or 0.1

% KMNO4.

disinfect large cuts - blister rust cankers (Cronartium

ribicola) on white pine branches.

Eradication of alternate hosts, wild hosts and weeds:

Inoculum level reduced . Examples: Brown rot of potato (Pseudomonas Solanacearum).

Avoid the collateral host. (Maize, sorghum, cumbu) for gummosis of

sugarcane (xanthomonas axanopodis pv.vascularum).

Seed cleaning:

winnowing,

salt sedimentation,

sieving,

flotation with water.

Crop rotation:Principles :

The crop grown between the susceptible host crops

should be resistant or immune to the pathogen .

The crops should be non-host and their root exudates

should not directly or indirectly favors for the pathogen.

Cereals- wilt of tobacco (Pseudomonas solanacearum)

sorghum - Moko wilt of banana (Burkholderia solancearum) - hydrogen

cyanide (HCN

When tobacco is immediately grown after maize there is a considerable

reduction in the incidence of Pseudomonas solanacearum on the later host. 

SANITATION:Reducing the inoculum in a field - removing and burning infected

plants or branches, and stubbles.

Reducing the spread of bacteria - decontaminating tools and hands

The crop residue burnt or ploughed deep into the soil with watering

to decomposition, The pathogens which cannot live saprophytically

in the soil.

Bacterial blight of cotton (Xanthomonas campestris pv. Malvacearum).

bacterial leaf streak disease (xanthomonas oryzae pv. oryzicola) . 

Vector control:

Bacterial wilt of cucurbits – cucumber beetles.

Citrus greening disease (Candidatus librobacter asiaticum)

transmitted by pysllid.

Papaya bunchy top (fastidious vascular phloem inhibiting bacteria)

transmitted by leaf hopper.

Soil tillage:Which accelerate the displacement of certain pathogen in crop

residues by resident antagonistic.

Some temperature susceptible pathogen are destroyed due to

high temperature in summer.

Soil sterilization: Soil treatment (steam, biocides or solarization) which

suppress or eliminate the pathogen but not the resident

soil saprophyte.

Example: copper or streptomycin- Bacterial wilt and canker of tomato-

(clavibactor michigenenses subsp. Michigenenses) .

Incorporation of bleaching powder (CaOCl) 15kg/ha in soil before

transplanting for management of tomato bacterial wilt (Ralstonia

solanacearum).

Resistant varieties: Crop breeding- resistant genes – different sources

BLB of rice caused by xanthomonas oryzae pv.oryzae –

IR 20, IR 36, IR 50, and IR 54.

Bacterial leaf streak disease (xanthomonas oryzae pv.

oryzicola) IR 20, TKM 6.

Bacterial blight of cotton (Xanthomonas campestris pv.

malvacearum). – sujatha and 1412 and CRH 71.

Adjusting fertilizing:stimulate the activity of resident antagonists - Incorporation of

compost and other organic materials.

Thinning and earthing up with potash for control Bacterial blight of

cotton (Xanthomonas campestris pv. Malvacearum).

low and split doses of N - reduce the intensity of the BLB of rice

( Xanthomonas campestrsi pv. Oryzae).

Avoid Water logging

In nurseries – BLB of rice,

Avoid Flooding or over irrigation

In field - soft rot disease 

Avoid overhead irrigationFavors for dispersal of pathogens.

Example:

watermelon fruit blotch disease – Acidovorax avenae subsp. citrulli.

Seed treatment:

1. Delinting - Cotton Seed- Concentrated Sulphuric Acid -

Bacterial Blight Of Cotton.

2. Soaking - Rice Seeds - 0.025% Strpetocyclic Solution -

Leaf Streak Disease Of Rice.

When infested superficially, can be disinfested with sodium hypochlorite or HCl solutions

Soaking - several days in a weak solution of Acetic acid.

If seeds can remain for 2 to 3 days in fermenting juices of fruit in which they are borne, bacterial pathogens can be eliminated.

Hot water treatmentWhen the pathogen is inside the seed coat and in the

embryo, such treatments are ineffective.

Not usually control bacterial diseases because of the relatively high thermal death point of the bacteria, but treatment at 52°C for 20 minutes - reduces the number of infected seeds.

cotton seed at 560C for 10 minutes for bacterial blight of cotton.

BLB of rice (xanthomonas oryzae) at 530c for 12hrs .

Clipping:Avoid clipping of seedlings - BLB by xanthomonas oryzae pv oryzae in rice .

CauterizationCankers on trunks and large branches - propane burner.

The flame is aimed at the canker and especially its margins for 5 to 20 seconds until the underlying tissue begins to crackle and char.

The treatment is carried out in early to mid-spring and, if necessary, should be repeated 2 to 3 weeks later

mulching

Biological control

Competition:competition for space and nutrient and oxygen

Example

The potato scab caused by Streptomyces scabies

controlled through application non-pathogenic strains of

Streptomyces.

Antibiosis:

Soft rot pathogen of potato (Erwinia carotovora subsp.atroseptica)

- Pseudomonas fluorescens migula F113 – DAPG.

Agrobacterium radiobacter strain k84 - agrocin 84 - pAgk84.

Inoculation of Agrobacterium strains k84 to the roots by

dipping in cell suspension - crown gall bacterium Agrobacterium

tumefaciens.

Siderophore:

Pseudomonas fluorescens migula F113 - potato soft

rot pathogen under iron limiting conditions.

REFERENCE :Article reference :

Abdallaha,M.E., Harounb,S.E., Gomahc, .A.A, El-Naggard ,N.E. and Badrc, H.H. 2013. Application of actinomycetes as biocontrol agents in the management of onion bacterial rot diseases. Archives of Phytopathology and Plant Protection, 15:1797–1808.

Thind B.S. 2013. Phytobacteriology and its changing scenario. Indian phytopathology, 66:229-236.

Maloy, O.C. 2005. Plant Disease Management. The Plant Health Instructor. DOI: 10.1094/PHI-I-2005-0202-01

Book reference :

Agrios 2005 . plant pathology 5th ed .Elsiver inc . 615-703

R.P singh 2013 plant pathology 2nd ed. Kalyani publishers. 234-244 and 268-285.

Kalyan k.mondel 2015 . plant bacteriology .Kalyani publishers 124-144

Online reference :

http://agriinfo.in/?page=topic&superid=5&topicid=1847

http://www.omafra.gov.on.ca/english/crops/facts/05-069.htm

THANKING YOU !!!