Biocontrol and IPM

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Biocontrol and IPM
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Reading Assignment Chapters 34 and 35
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Biocontrol

• Control of plant pathogens with other microbes
• A biological control agent is known as an
  antagonist
• Antagonism is general name for mechanisms of
  biological control

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Antagonism
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Antibiosis
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Competition
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Parasitism
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IPM

• IPM is the management of diseases by optimizing
  control strategies to prevent diseases from
  causing economic losses
• Purpose of disease control prevent disease
  damage from exceeding level where profit or
  required yield is significantly diminished

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How do we prevent profit losses?

• Reduce (delay) disease at the beginning of the
  season (Xo)
• Decrease rate of disease development (r)

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When do we act?

• Economic injury level damage threshold the
  level Xt at which disease begins to be adversely
  affect yield and/or quality
• Level of injury may vary from one region or
  farmer to the next region or farmer

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When do we act?

• Action threshold Economic threshold
  pathogen density at which control measures should
  be taken to prevent pathogen from reaching the
  economic injury level
• Farmer must act to reduce r so that disease dose
  not reach EIL before harvest

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Economics

• Growers can be expected to increase resources for
  crop protection until the amount of money
  expended additional crop income

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Factors that effect economic thresholds

• Producers attitude
• Crop income disease incidence relationship
• Control costs pathogen population relationships

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Economics

• Tolerance level amount of disease where crop
  income falls as disease levels increase
• Income losses can result from decreased yields
  and/or decreased quality
• How much disease can be tolerated on a poinsettia
  or a golf green?

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What the grower should know

• Value of yield
• Probable cost of disease control
• Cost of several alternative control measures

• Efficiencies of controls in reducing disease
• Expected impact of a given pathogen intensity on
  quality and quality of yield

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What can influence farmers decisions?

• Level of credit or affluence
• Undetected crop loss
• Aversion to risk