Integrated Pest Management

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Integrated Pest Management
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Agricultural Pests

• Weeds
• Insects
• Nematodes
• Diseases
• Snails and slugs
• Vertebrates (rodents, birds, etc.)

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Pesticide Use on Major US Crops
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Management (IPM) vs Control or Eradication

• Eradication?? Is that really possible??
• 1960s Traditional IPM
• Integrated coordinate several methods
• Pest all pests, not just one type
• Management manage vs control

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Management vs Control

• Maintain populations below damaging levels
• Responsive treatment (treatment as needed) vs
  preemptive treatment

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Management vs Control

• Maintain populations below damaging levels
• Responsive treatment (treatment as needed) vs
  preemptive treatment
• Requires effective management tactic (often a
  pesticide, but objective is to reduce pesticide
  application to when it is needed)
• Usually requires some sampling or monitoring of
  populations
• Usually requires a damage threshold

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Crop Damage Threshold
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Crop Damage Threshold
No loss in yield at very low pest densities
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Crop Damage Threshold

• pest density at which yield is decreased (may
  not be same as first evidence of pest damage)
• Form of yield loss or damage relationship to pest
  population density varies with pest and crop
• Many plants can tolerate some damage (e.g., low
  amounts of defoliation may not affect yield)

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Thresholds

• Crop damage threshold (does not involve )
• Economic threshold general term used to
  describe pest density at which treatment is
  necessary to prevent economic injury. Several
  types of economic thresholds may be specified
• Economic Injury Level pest density at which
  value of yield returned (damage prevented) equals
  cost of control.
• Action Threshold pest density at which
  treatment is necessary to prevent economic injury
  (to prevent population from reaching EIL).

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Economic Injury Level
Change in Yield when pests are reduced by
treatment
P Treatment reduces pests from level X to level P
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Economic Injury Level
Change in Yield has some value that is gained
Reducing pests costs
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Economic Injury Level
EIL Point at which yield returned () cost
() of control
Change in Yield has some value that is gained
Reducing pests costs
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Economic Injury Level
EIL Point at which yield returned () cost
() of control
Change in Yield has some value that is gained
Suppose EIL is here
Reducing pests costs
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Economic Injury Level
EIL Point at which yield returned () cost
() of control
Suppose EIL is here
Treating at point above X (EIL) returns more
than the cost of treatment
Treating at point below X (EIL) will not pay for
cost of treatment
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Economic Threshold

• If pest population gt EIL Treat
• If pest population lt EIL Dont treat

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Economic Threshold

• If pest population gt EIL Treat
• If pest population lt EIL Dont treat
• What if pest population changes rapidly over time
  ?
• What if you cant apply treatment right away ?
• Pest population could reach or pass EIL while we
  wait around to treat !

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Thresholds

• Crop damage threshold (does not involve )
• Economic threshold general term used to
  describe pest density at which treatment is
  necessary to prevent economic injury. Several
  types of economic thresholds may be specified
• Economic Injury Level pest density at which
  value of yield returned (damage prevented) equals
  cost of control.
• Action Threshold pest density at which
  treatment is necessary to prevent economic injury
  (to prevent population from reaching EIL).

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Action ThresholdTreat at AT to avoid reaching EIL
AT often used in entomology, insect populations
change rapidly over time
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Economic Thresholds

• Static situation react to treatment at one
  point in time -- e.g., anticipated yield related
  to density of a soilborne pest prior to planting
  decision is whether to use soil fumigation or
  not.
• Dynamic situation insect population changes
  during season population level recorded during
  scouting may increase to even higher level before
  insecticide can be applied

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To work with AT and EIL, must know

• Plant damage/pest density relationship
• Sampling of pest
• Cost and performance of treatment
• Economic forecast of crop value
• Scouting programs survey fields to supply these
  data

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Integrated Management

• Combination of two or more tactics in management
  of a pest
• Example management of pest mites in apple
  orchards by acaricide sprays and biological
  control from predatory mites (see Ch. 13 by Croft
  in Metcalf and Luckmann, 1994)
• Replacement of effective pesticides by
  non-chemical methods may require integration of
  several management methods (e.g., integrating
  solarization crop rotation to substitute for
  methyl bromide)

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Integrated Management of Mites in Apple Orchards
NO SPRAY
Predatory mite population
SPRAY
Pest mite population
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Integrated Pest Management

• Could include management of several different
  kinds of pests (e.g., crop rotations to affect
  soilborne insects, diseases, nematodes, weeds)
• Whether integrated or not, management methods
  directed at one pest may affect other pest groups
  and nontarget organisms (e.g., herbicide-killed
  weeds affect nematodes, diseases, etc.)

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Traditional IPM

• In practice, many examples of IPM are management
  of insects with insecticides
• Traditional IPM has resulted in reduced number of
  insecticide sprays and savings in

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Limitations to more wide use of IPM

• Lack of information on
• Thresholds
• Pest biology
• Sampling methods
• Effective management methods
• Etc

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Future IPM in whole farm context
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Ecological Basis for Pest Management

• Future Moving beyond IPM to ecosystem redesign
• Contrasting approaches for pest management

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Traditional IPM Treat when needed to keep pest
below economic injury level, but natural tendency
of pest population to expand toward K
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Organic Agriculture Redesign system to obtain K
below economic injury level but requires much
knowledge of pest ecology
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Organic Agriculture Redesign system to obtain K
below economic injury level but requires much
knowledge of pest ecology
Redesign to lower K by using different crop
variety, biocontrol agents in system, etc.
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References

• Text, Ch. 11, pp. 226-239.
• Carroll et al. 1990. Ch.15.
• Metcalf and Luckmann. 1994. Chs. 1, 13.