Why study plant diseases?

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Why study plant diseases?

Starving boy and girl turning ground looking for
potatoes
Illustrated London News, February 20, 1847
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ErgotismClaviceps purpurea

• Disease of rye
• Invades grain and produces sclerotia where grain
  would be
• Sclerotia contain high amounts of LSD

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What happened?

• Europe plagued with epidemics of ergotism for
  centuries
• 10,000s die from holy fire or Vitus dance
• Monks of the Order of St. Anthony treat people
  with holy fire by feeding them bread made with
  flour not contaminated with ergot sclerotia

St. Anthony
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Ergot and Witches?

• The witch trials in Salem may have been due to
  an outbreak of ergotism.
• The women and girls (both accused and accusers)
  all had symptoms associated with ergotism.

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Peter the Great and Ergotism

• He coveted Turkeys warm water ports on the black
  sea
• Led army south, but when it entered area of Volga
  River, stumbled onto ergot epidemic

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Peter the Great and Ergotism

• Soldiers ate rye bread horses ate rye hay.
• Horses came down with blind staggers soldiers
  had convulsions and 20,000 died.
• Peters army retreats back to Russia defeated
  before they could actually begin.

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Provence, France and Ergotism

• Epidemic occurred in 1950s
• 1st case was initially thought to be
  appendicitis, but symptoms were low fever, cold
  fingertips and hallucinations instead of abdomen
  pain
• Three days later hospital full and 70 private
  houses had to be made into sick wards
• Country side panics when 1st patient dies of
  agonizing convulsions!

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Provence, France and Ergotism

• Mayor orders house to house search for clues to
  cause
• Investigators uncover that all patients from
  three villages had eaten bread from same baker
• Twenty poisonous alkaloids, including LSD, found
  in flour at bakery

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Provence, France and Ergotism

• After weeks of investigation it turned out the
  farmer, the miller and the baker all knew the
  grain was poisoned, but didnt want to loose
  money.
• More than 200 people suffered hallucinations, 32
  went insane and 4 died.
• Now, who wants a BLT on rye for lunch?

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Late Blight of Potatoes Phytophthora infestans

• In mid 1800s Irish population similar to what we
  see in many poor countries today population at
  limits of food supply.

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Late Blight of Potatoes

• With introduction of potato from new world,
  farmers can grow 3x as much food / ha
• Population of Ireland doubles again

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Late Blight of Potatoes

• 1844 late blight appears in U.S in 1845,
  epidemic sweeps Ireland like a storm
• Not only did many starve and die, but many were
  evicted from their homes

Taking starvation victim from home
Eviction from home by landlord
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Scenes of the Famine
Food riot at Galway. Relief supplies had to be
moved under armed guard to protect the food
from armed bands of robbers.
Irish farmers departing Ireland for the US to
escape the famine.
Mrs. ODonnel and two of her children. An older
boy (13) and a newborn had already starved when
this drawing was made.
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Late Blight of Potatoes

• Millions die from starvation and more than a
  million immigrate to U.S.
• Immigrants treated as second class citizens and
  take low paying, dangerous jobs as policemen,
  firemen and miners.

1846 U.S. political cartoon about Irish
immigration
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Late Blight and WW I

• By 1916, Bordeaux mixture was used to control
  late blight was effective
• 1916, growing season for potatoes in Europe was
  unusually cold and wet
• Copper was scarce because of its demand for
  shells and brass buttons
• Soldiers for German army had enough to eat, but
  letters from home told of despair and starvation.
  German army became demoralized and collapsed 2
  yrs later

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Coffee Rust Hemileia vastatrix

• Arabs brought coffee from Ethiopia around 100 AD
• Islamic Turks established coffee houses by 1550
  and roasted beans moved to Europe
• Arabs careful not to let live beans out of
  country

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Coffee Rust

• Because of sewage problems in London and other
  cities, Brits boiled drinking water in 1800s.
  By 1870, tea was out and coffee was in.
• A Muslim from S. India, while on a pilgrimage to
  Mecca, rose above his religion and stole 7 live
  beans. In India (under British control), coffee
  flourished and the bean was taken to the Ceylon
  (Sri Lanka).

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Coffee Rust

• Disaster struck when coffee rust was found in the
  Ceylon.
• Trees died faster than they could be replaced.
• Coffee yield had dropped to zero.
• At the beginning of the coffee rust epidemic,
  there was 500 ha of tea in Ceylon. Ten years
  later, there were 140,000 ha of tea there.

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Chestnut BlightCypronectria parasitica

• Before the chestnut epidemic, 1 of every 4 trees
  in Appalachia was a chestnut.
• Chestnut lumber was resistant to rot and the wood
  produced tannins needed for preserving lumber.
• Today, creosote plants or other preservatives are
  needed to treat pine lumber and synthetic tanning
  agents are used with leather. These substitutes
  are based on fossil fuels.

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Dutch Elm DiseaseOphiostoma ulmi

• During WW I, trenches on both sides were dug with
  Chinese labor who had brought there belongings in
  wicker baskets made of Chinese elm.
• Some baskets had wood that contained the fungus
  and the beetles that vectored the fungus.
• Millions of European elms died.
• The Dutch were victims like others in Europe.

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Dutch Elm Disease

• The owner of a veneer factory in Ohio saw a
  chance to make lots of by importing cheap
  lumber from Europe.
• Imported logs had both the fungus and vectors and
  introduced the disease into the U.S. heartland.
• Millions of American elms have died.

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Southern Corn BlightHelminthosporium maydis

• Hybrid seed corn was expensive when tassels from
  plants being used as the female parent had
  tassels removed by hand.
• By end of the 1960s, all seed corn was produced
  using Texas Male Sterile Cytoplasm which made
  the pollen of the female parent sterile.

Male and female corn rows being used to produce
hybrid seed corn
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Southern Corn Blight

• In 1970, epidemic of corn blight by new race
  specific for plants with Texas male sterile
  cytoplasm found in southern US
• 15 of US corn supply loss in 1970 ( enough to
  feed sufficient cattle to make 30 billion Big
  Macs)
• USDA projections were for 90-100 loss in 1971.
  Why did this not happen? Seed companies produced
  seed the old fashion way in South America during
  winter of 1970-71.

Southern blight symptoms
Field killed by southern corn blight. Note green
weeds.
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Why study plant diseases?

• Plant pathogenic fungi can have a profound
  negative affect on worlds food, fiber or timber
  supplies and severely impact quality of lives.
• Plant pathogens can be used as bioterrorism
  weapons.
• Plant disease epidemics can cause loss of life
  through starvation in areas where the population
  is near limits based on food supply.

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Reading AssignmentChapters 1 and 2