Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Resurgence - Integrated Pest Management - Handout, Exercises of Pest Management

Main topics of this course are: Biocontrol Approaches, Decision Making, Disadvantages of Cultural Controls, EBPM Status, Enforced Crop Production Rules, Hybrid Sterility, IPM Evolution Continued, Regulatory Tactics, Resistance Categories. Key points of this lecture handout are: Resurgence, Pesticide, Pest Resurgence, Reduced Biological Control, Resistance, Resistant Mechanism, Resistance Process, Management Strategy, Impact of Resistance, Environmental Impact

Typology: Exercises

2012/2013

Uploaded on 08/31/2013

jaee
jaee 🇮🇳

4.7

(22)

101 documents

1 / 10

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Resurgence
Mostly documented with insect pests
Mostly associated with indirect, secondary/minor pests for several
reasons.
Key pests are watched too closely to resurge
Direct pests are mainly late-season pests & there isnt time to resurge
Pest must be held at least partially in check by some agent that is affected by the
pesticide
Note Fig. 12-6 in book.
pf3
pf4
pf5
pf8
pf9
pfa

Partial preview of the text

Download Resurgence - Integrated Pest Management - Handout and more Exercises Pest Management in PDF only on Docsity!

Resurgence

  • Mostly documented with insect pests
  • Mostly associated with indirect, secondary/minor pests for several reasons. - Key pests are watched too closely to resurge - Direct pests are mainly late-season pests & there isn’t time to resurge - Pest must be held at least partially in check by some agent that is affected by the pesticide
  • Note Fig. 12-6 in book.

Four processes contribute to resurgence

  • Reduced Biological Control (Secondary) – most common with

insects

  • Reduced Competition – most common with weeds (mono vs.

dicots)

  • Direct Stimulation of Pest – usually due to sub-acute doses
  • Improved Crop Growth

Resistance

  • Mostly a problem with pesticides (so far) but applies to all

management tactics. Ex:

Resistance as a process

The process has three general stages, each with its own

Management Strategy

Impact of Resistance

  • Overall agricultural productivity (during build phase)
    • Increased pesticide usage
    • Increased damage
  • Environmental impact
    • Increased pesticide usage
    • Increased use of non-renewable resources
    • Increased acreage
  • Pest management flexibility
    • Loss of pesticide tactic
  • Constraint on new pesticides

Causes of Resistance

Independent of Pesticide

  • Genetic Factors
  • Ecological Factors
  • Severity of Selective Pressure

1. Genetic Causes of Resistance

  • Genetic Factors
  • Voltinism
  • Generation time
  • Fecundity
  • Behavioral factors

3. Selection Pressure

  • Selective pressure is “high” if a “low” percentage of susceptibles survive to reproduce - Reduce pressure by: (1) reduce dosage & (2) reduce frequency
  • Site of action
    • Alternating modes of action reduces pressure
  • Spatial coverage – reduce pressure by reducing coverage
  • Timing – Using pesticides after reproduction reduces selective pressure

Resistance Categories

  • Resistance to individual pesticides
    • Delayed entrance of toxicant
    • Increased deactivation/decreased activation
    • Decreased sensitivity
    • Behavioral avoidance
  • Resistance to multiple pesticides
    • Cross-resistance & class resistance
    • Multiple resistance
    • Multiplicate resistance

Resistance Management

  • Strategy
  • Reversal
    • Cease use of pesticide causing resistance. Problems
      • Probably the preferred control
      • May be used for other pests
      • Area-wide enforcement usually necessary
    • Refugia
    • Use synergists
    • Genetically manipulate the pest population (Gene Driving)