pathogenesis citrus canker

Citrus Canker: Symptoms, Causal Organism and Control Measures – Pathology Lecture Notes

citrus canker causal organism

Citrus Canker
(Symptoms, Causal Organism, Etiology and Control Measures)


Citrus is the common term for the fruits of the genus Citrus of family Rutaceae. They are native to Australia and now cultivated all over the world in cooler climates. Common examples of fruits from Citrus are oranges, lemons, grapefruits, limes etc.

Citrus Canker

Ø  Citrus canker is a bacterial disease.

Ø  It is wide-spread in all the citrus growing areas.

Ø  It is one of the serious disease affecting citrus plants in India, China and Japan.

Ø   The disease was originated in China and now it causes large-scale destruction in citrus orchards.


canker symptom leaf

Ø  The canker occurs on leaves, twigs, branches and fruits.

Ø  The lesions first appear on leaves.

Ø  The spots first develop on the lower surface of the leaf.

Ø  In the beginning; the lesions will be small, round and watery.

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loss of rice due blast disease

Blast Disease of Paddy: Symptoms, Causal Organism and Control Measures

blast of rice

Blast Disease of Paddy
(Symptoms, Casual Organism, Etiology and Control Measures)

loss of rice due blast diseasePaddy/rice

Rice is a cereal grain. It is the seeds of Oryza sativa (Asian rice) or Oryza glaberrima (African rice). Rice is the most extensively consumed staple food of human. It is the major staple food in Asia. Rice is the third highest agricultural commodity in worldwide production. The un-milled rice is known as “paddy“.

Blast Disease of Paddy

Ø  Blast disease is one of the most severe diseases affecting paddy.

Ø  It is a fungal disease prevalent all over the world.

Ø  It is a major problem in rice production in countries like Japan, India, Taiwan and the USA.

Ø  Blast disease is more severe in areas with high humidity and rainfall.

Ø  Losses due to the disease may be up to 90% of the total corp.

Ø  In India, the blast disease is more common in Southern parts, particularly coastal areas.

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