Causal Organisms of Plant Diseases

Causal Organisms of Plant Diseases

List of contents
01: Bacterial diseases of plants
02: Phytoplasma diseases of plants

01: Causal organisms of the bacterial diseases of plants

S.N.Name of diseaseCausal organismMore information
01.Citrus cankerXanthomonas axonopodis pv citri.01. Other name: Asiatic citrus canker and A form canker
02.Bacterial blight of cottonXanthomonas axonopodis pv malvacearum (Smith)01: Other names: Angular leaf spot or black arm of cotton
03.Bacterial leaf blight of riceXanthomonas oryzae pv oryzae01: Also known as BLB
02: It survives in many alternate host during off season
04.Bacterial leaf streak of riceXanthomonas oryzae pv oryzicola01: Wounds caused by insects aare a major source of entry of the pathogen into the leaves
05.Bacterial blight and canker of mangoXanthomonas campestris pv mangiferae-indicae01: Copper oxychloride is very effective against the bacterial blight of mango
06.Black rot of crucifersXanthomonas campestris pv compestris01. The main source of survival of the bacterium is seed
07.Red stripe and top rot of sugarcaneAcidovorax avenae subsp. avenae (Manns)01. Infection starts through wounds and through stomata
02. Once the disease sets in it is very difficult to manage
08.Brown rot and wilt of potatoRalstonia solanacearum (Smith)01. It is soil borne disease
02. Bacterial population in soil increase with symptom development in the plant and decline when the plant is dead
09.Bacterial wilt of tomato and other solanaceaeRalstonia solanacearum01. The attack of root knot infection worsen the disease
10.Bacterial rot of wheat earsRathayibacter tritici 01. Field soil is not a source of inoculum
02. Galls on plant show the presence of the bacterium

Bacterial diseases: 11-14

S.N.Name of diseaseCausal organismMore information
11.Ratoon stunting disease of sugarcaneLeifsonia xyli subsp. xyli01. The RSD bacteria is sap transmitted
12.Black leg, wilt and soft rot of potato01. Pectobacterium Cartovorum ssp. cartovorum
02. Pectobacterium Cartovorum ssp. atrosepticum
01. Pathogens are present in rotting tubers
02. Severity of decay of potato tubers is influenced by potato genotype, tuber immaturity, harvest in warm conditions, high water potential, low calcium content, high nitrogen fertilization, and interaction with other pathogens
13.Common scab of potatoStreptomyces scabies01. Streptomyces scabies can persist in soil indefinitely
02. There are two types of lesions on the tuber, the shallow and the deep scab
14.Citrus greening deseaseMLO or mycoplasma like organism01. It is common throught the world as a destructive disease
02. Severely affected species are sweet orange, mandarin and tangelo trees
Also read: Insect Vectors of Plant Diseases

Phytoplasma Diseases of Plants

Also read: Phytoplasma Plant Diseases Examples

S. N.Name of diseaseCausal organism Other information
01.Grassy shoot disease of sugarcaneMycoplasma Like Organism (sugarcane white leaf phytoplasma group)01. The vectors are Rhopalosiphum maidis (Aphis maidis), and Melanaphis sacchari form indosacchari
02.Little leaf of eggppantMycoplasma Like Organism (phytoplasma of the clover proliferation group01. Loss is up to 90%
02. Vectors: Aphids
03.Phytoplasma diseases of potato1. Purple top roll of potato
2. Marginal flavescence
3. Witches broom
Purple top roll of potato
1. Vector: Orosius albicinctus
2. Causes sterility in plants

Marginal flavescence
1. Prevalent in hills and plateau in coolnweather
2. Loss may vary fr 40-70%

Witches broom
1. Stream stunting of plant
2. Vector is leaf hopper
04.Sandal spike diseaseMycoplasma like organism (member of the aster yellows phytoplasma)01. Other name: Rosette spike
02. Sandal spike is a yellow type disease with witches effect
03. Vector is leaf hopper
04. Mode of transmission is root contact and insecet vector
S. N.Name of diseaseCausal organism Other information

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