Agricultural Plant Pathology

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Agricultural Plant Pathology
PLSS/PSAS 401Dr. Jason BondMr. Chris Vick / Ms.
Amelia Vick

• Labs
• Disease of Horticultural Crops Mon 3-5 - Bond
• Diseases of Field Crops Mon 1-3 Dr. Fakhoury
• Diseases of Turf Dr. Diesburg
• Diseases of Trees Mr. ?

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Why study plant diseases?

• Plant pathogens can have a profound negative
  affect on worlds food, fiber, or timber supplies
  and severely impacts quality of lives.
• Plant disease epidemics can cause loss of life
  through starvation in areas where the population
  is near limits based on food supply.
• The study of plant pathology can provide
  incredible insight into microbial ecology, host
  physiology, epidemiology, and this insight can be
  directly translated into similar studies
  involving animal systems.

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Why study plant pathology?

1. Securing a stable and healthy food supply

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Why study plant pathology?

1. Fundamental research in plant-microbe interactions

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Importance of Plant Pathology

• Politics Irish potato famine in mid 1800s
  (800,000 died, 1.5 million emigrated). Many came
  to the U.S., including Kennedy family.
• Culture Coffee rust decimates coffee
  plantations Sri Lanka and India. Switch to tea
  because of resistance. Hence British are tea
  drinkers. It is why we had the Boston Tea party
  instead of the Boston Coffee Party.
• History In 1722, Peter the Greats invasion of
  Europe was halted by St. Anthony's Fire, now
  known to be caused by ergot disease of Rye.
• During WWI, late blight devastated potato
  production in Germany and likely hastened the end
  of the war.

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Importance of Plant Pathology

• Mythology Roman gods Robigus and Robigo were
  worshipped. These corresponded to the different.
  stages of wheat stem
  rust disease. The Robigalia festival was
  designed to appease these gods and ensure a
  disease-free harvest.
• Religion many mentions of blast, mildews, etc.
  in the Bible.

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Plant Disease?

• Any abnormality of a plant, its parts, or its
  products that reduces their economic or aesthetic
  quality.
• Any alteration of a plant that interferes with
  its normal structure, function or economic value.
  
• Abnormal plant physiology.
• Malfunctioning of host cells and tissues that
  results from continuous irritation by a
  pathogenic agent or environmental factor and
  leads to the development of symptoms.

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Plant Disease?

• These definitions have the following in common
• Abnormal a better term would be unhealthy or
  malfunctioning. A crop variety that yields 2X
  normal would be considered abnormal.
• Physiology all diseases affect at least one
  physiological process and most affect more than
  one. Ex. respiration, photosynthesis,
  absorption, translocation, reproduction,
  assimilation, storage.
• Pathology the study of suffering

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Categories of Disease

• Biotic caused by infections living organisms
  such as fungi, bacteria, nematodes, viruses, etc.
• Abiotic caused by non-infectious environmental
  factors such as temperature, herbicides,
  pollutants, etc.

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Plant Disease Triangle

• Shows how factors interact to produce disease.

• Environmental must be fav. for H and P
• Pathogen must be virulent
• Host must be susceptible

E
T
H
P

• Time some add this or other factors,
• dep. on disease