1 / 17

Benefits/Concerns Over HRC

Benefits/Concerns Over HRC. Benefits Simplifies weed management Speeds adoption of reduced tillage systems Overall reduction in pest losses Concerns Will eventually create herbicide-resistant weeds Unknown pleiotropic effects Regulatory/marketing issues

erik
Download Presentation

Benefits/Concerns Over HRC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Benefits/Concerns Over HRC • Benefits • Simplifies weed management • Speeds adoption of reduced tillage systems • Overall reduction in pest losses • Concerns • Will eventually create herbicide-resistant weeds • Unknown pleiotropic effects • Regulatory/marketing issues • Over-reliance on them will prematurely end their usefulness

  2. Using HPR in IPM • As a stand-alone tactic • Objective is to preserve the resistance; emphasis on deployment strategy • Integrated with other tactics • Crop rotation: if HRC’s are used, must rotate both for pest and herbicide type. • Pesticides: Emphasize measures to prevent pesticide resistance (lower doses, frequency) • Biological control: Conflicts do occur • Action Thresholds: Whenever there is significant, cultivar-specific variation in yield response to a pest, action thresholds should be re-examined

  3. Behavioral Control • Your Text Follows This Outline: • Vision-based tactics • Auditory-based tactics • Olfaction-based tactics • Food-based tactics • Lecture Will Follow This Outline • Behavior modifiers • Mating disruption • Genetic manipulations

  4. Behavior Modifiers Most insect behavior modifiers are chemical • Semiochemicals – Facilitate communication between individuals • Pheromones: within a species • Allelochemicals: Between species • Allomones: Producer benefits, receiver does not • Kairomones: Receiver benefits, producer does not See book discussion, pp: 379 – 382. Pay particular attention to the pheromone types.

  5. Pheromone Usage • Sex pheromones most widely used in IPM • Relatively simple chemistry enables synthetic versions. • Three main uses in IPM: • Monitoring one sex • Mass trapping sexually active adults • Interfering with mating • A few “Anti-pheromones” are now available. Future use unknown. Here’s an example.

  6. Pheromone Disperser Examples Plastic Spiral Card style Cable/Twist Tie Rubber septum (with holder)

  7. Kairomone Usage • Most are attractants used as baits to attract pests to traps or bait stations. Examples: • Curbitacin & cucumber beetles • CO2 and mosquitoes • Protein hydrolysates and fruit flies • Normally attract both males & females • “Attracticide” – lure mixed with toxin

  8. Allomone Usage • Mostly used as repellents • DEET • Neem extracts • Many are experimental & their use is still only a promise • Plant attractants for biocontrol agents • Feeding deterrents • All have short residual activities

  9. Mating Disruption • Floods area with sex pheromones (cf. Fig. 14-6, p. 387). Also known as “pheromone inundation” & “air permeation” • Application may be via recoverable or non-recoverable methods • Problem: Sex pheromones mostly used with species that have high mobility. • Requires large area coordination • Many site-based characteristics affect result

  10. Genetic Controls Four categories • Sterilization – Mass release of sterilized individuals • Conditional Lethal Releases – Released individuals carry lethal genes • Hybrid sterility – Progeny will be non-viable • Other – To be developed

  11. 1. Sterile Insect Technique (SIT) • Steps: 1. Mass rear pest, 2. Sterilize males, 3. Flood area with these males, 4. Females will mostly mate with sterile males • Uses one of two sterilization techniques • Nuclear • Chemical • Many successes • Most famous application was the screwworm eradication.

  12. Progression of Screwworm Eradication

  13. Requirements for SIT • Works best on population with low fecundity • Five Conditions • Must be able to treat entire population • Sterilization cannot debilitate males • Releases must mix sterile males well • Females should only mate once • Must sustain high ratio of sterile:wild males

  14. 2. Conditional Lethal Release • Release individuals that have a gene that proves fatal under specific conditions • Main paper here • Advantages over SIT • Can release both males & females • May require fewer released individuals • Can insert a wide variety of genes • Disadvantage: Requires several pest generations before “lethal condition”

  15. 3. Hybrid Sterility • Males & Females of different strains can produce non-viable offspring • Incompatible strains can be generated through several ways • Direct genetic manipulation • Microbially-mediated (Cytoplasmic Incompatibility)

  16. Example: Wolbachia in lower flies

  17. For Next Wednesday • IPM in KY Peppers • See Readings for Additional Items • Read Chapter 15, Physical & Mechanical Tactics

More Related