Download Pesticide & Host Plant Resistance in IPM: Categories, Management & Advantages and more Slides Pest Management in PDF only on Docsity!
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
- Saturation
- Moderation
- Multiple Attack
- Tactics
Final Note
- All management tactics are susceptible to
resistance
- Resistance best managed preventatively
- Pest management needs to pay more
attention to resistance management
- Resistance management will become a
greater part of pest management over the
coming years
Host Plant Resistance in IPM
Your book uses the following approach
- Host Plant Resistance (HPR) – General
Concepts
- Conventional Plant Breeding
- Genetic Engineering
- Application of Pest Genetics in IPM
Our lecture will mostly concern additional material
Characteristics of the Pest
Complex
- Damage Concentration – Complex with
most damage confined to a few pest
species is a good candidate for HPR
- Identifiable plant-pest dependency
- No conflicting pests
- Few direct pests (HPR will likely make
product less usable)
Advantages/Disadvantages of HPR
- Advantages: See list pp: 444 – 445
- Disadvantages
- Time required
- Genetic Limitations
- Pest Biotypes/Races
- Conflicting Agronomic/Marketing Traits
- Conflicting Pest Management Traits
HPR and the Injury Scale
- “True” Resistance
- Immunity – often restricted to a specific race
- Highly Resistant – Relatively little injury
- Low-Level Resistance – Less injury than avg.
- Susceptible – About average injury
- Highly Susceptible -- More than average
- “Partial Resistance” – High & low-level
- Note – “Susceptible” does not mean
“defenseless”, means average injury. Changes with change in prevailing cultivars.
HPR and the Yield Scale
- “Tolerance”
- Highly, Moderately Tolerant; Intolerant, Highly Intolerant
- Creates two problems
- Pest builds up & may cause other problems
- Affected by many other factors (e.g. soil, nutrition, other pests) but the net effect can’t be measured until harvest.
Factors that affect resistance
expression
- Physical Factors
- Plant Nutrition
- Biotic Factors
- Plant factors
- Pest factors
- Biotype
- Initial infestation level
HPR as a response by the pest
- Antixenosis (non-preference) -- prevents pest
from commencing attack. Two types
- Chemical – Allelochemicals are chemicals produced by one species (plant) to affect another species (pest).
- Morphological – can be very long lasting.
- Antibiosis – Interferes with pest attack once it
begins.
- Pest has reduced survival, fecundity, reproduction, etc.
- Two types
- Primary metabolite missing
- Toxin
Genetic Basis of HPR
- Better understood for pathogens
- Fewer control options
- Effect of races more pronounced
- Closer genetic association between pathogens & plants
- Horizontal vs. Vertical Resistance
- Vertical – based on one gene
- Horizontal – based on >1 gene
Vertical – “All or None”
Vertical vs. Horizontal Resistance
in IPM
- Vertical’s advantages over horizontal
- Amenable to simple, qualitative scouting methods
- Easier to develop & manipulate
- Effectively resists initial attack vs. changing the rate of increase after attack
- Vertical’s disadvantages relative to horiz.
- May be too specific (single race)
- May be overcome by pest more easily
