Role of Phytopathology in

Agriculture

D.M.S.K.Dissanayaka

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What is Phytopathology

• The scientific study of plant diseases and

their causes, processes, and effects.

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Objective in Phytopathology

1. To study the disease (s) or disorders caused by biotic and abiotic agent.

2. To study the mechanisms of diseases development by pathogens.

3. To study of interaction between plant and pathogen in relation to the overall environment.

4. To develop suitable management strategies for managing the diseases and losses caused by them

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World population is increasing day by day

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31 October 2011 ?

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Need additional food supply to feed the people

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Also in the present situation, more than 800 millions of people do not have adequate food sources.

1.3 billion lives on less than $1 per day

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• 1.3 billion tons of foods are wasted per every year

• At least 10% of global food production is lost due to plant diseases

•Therefore , can’t ignore these figures for the damageto food production causedby plant pathogens

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• 14 crop plants provide the bulk of food for human consumption.

Any disease which affects to these crops reduces the food production than other crops

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examples for plant diseases that affected to the food production

• Wheat Stem rust The major diseases of wheat and barley.

Wheat is the largest food crop in the world, and barley is

the fifth largest. It supply more than 25% of the world

food supply.

$5 billion are lost due to cereal rusts each year.

As a precaution for that, the newly improved

resistant varieties were introduced based on the

Phytopathological basis

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(Agrios,G.N, 2005)

• The Irish Famine, Late Blight epidemic of Potato in Ireland 1846-1850

Causal organism - Phytophthora infestans

Impacts

By the end of the famine, the population

of Ireland dropped from 8 million

to 5 million people.

Around 6 million peoples migrated between 1847 &1854 to other countries.

Remarks

This single disease forced man to realize the importance of plant diseases.

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• The Bengal Famine of 1943Causal organism – Bipolaris oryzae

Impacts

1/3of rice production was reduced in India.

3.5 million people died of starvation.

• Lethal yellow epidemic of coconut in CubaCausal organism – Phytoplasma

Impacts

Forced the Cuban people to shift over to sugarcane

plantations from coconut.

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Coffee rust epidemic in Sri Lanka 1870s

Causal organism- Hemileia vastatrix

Impacts

Declined 93% export of coffee from Sri Lanka .

Economic crisis forced the planters to cut down coffee plants and take to tea planting.

Brazil became a major coffee exporting country in the world after this famine.

Remarks

This disease showing that people have to change their food-habit due to a disease.

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Banana Sigatoka epidemic in central and south America- 1930s

• Causal organism- Mycosphaerella musicola

Impacts

Ruined the entire banana industry in central and south America.

Remarks

The epidemic saved by 1940 when Bordeaux mixture was used to control the disease successfully.

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References

• Global Food Security and Plant Diseases http://www.academia.edu/7279648/Global_Food_Security_and_Plant_Diseases

• Wikipedia

https://www.wikipedia.org/

• American Phytopathological Society

http://www.apsnet.org/edcenter/intropp/lessons/fungi/Basidiomycetes/Pages/StemRust.aspx

• Agrios,G.N,(5th edition 2005),Plant Pathology. Elsevier academic press, University of Florida.

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