This document discusses various cultural, mechanical, and biological methods for managing plant bacterial diseases. It begins by emphasizing the importance of using disease-free propagation materials and seed certification programs to avoid introducing pathogens. It then describes methods such as eradicating infected plant parts, controlling alternate and weed hosts, seed cleaning, crop rotation, and vector control. The document also discusses practices like soil tillage, sterilization, use of resistant varieties, and adjusting fertilization. Additional control techniques involve avoiding conditions that favor disease spread, as well as methods like clipping, cauterization, mulching, and biological controls using competition, antibiosis, and siderophores.
2. 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)
3. 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),
4. 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.
5. 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
6. 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),
7. 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.
8. 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).
10. 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.
11. 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.
12. 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.
14. 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.
15. 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.
16. 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).
18. 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.
19. 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).
24. 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.
25. Hot water treatment
When 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 .
28. Cauterization
Cankers 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
31. Competition:
competition for space and nutrient and oxygen
Example
The potato scab caused by Streptomyces scabies
controlled through application non-pathogenic strains of
Streptomyces.
32. 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.
34. 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
