LECTURE 9 CROP PROTECTION AKA PESTICIDE USE

1
LECTURE 9CROP PROTECTION AKA PESTICIDE USE
2
Some Definitions

• Pesticide a substance that kills a pest
  (insect, weed, bacteria, nematode)
• Herbicide weed killer
• Insecticide insect killer
• Rodenticide rodent killer

3
Why are pesticides used in agriculture, society
and the environment?

• 1. Agriculture
• a. Use of crop protecting agents improves yield
  and quality of agricultural products, consumer
  preferences
• b. Prevents the spread of diseases to crops and
  livestock (Pierces Disease)
• c. The use of pesticides is regulated by the
  E.P.A. (Environmental Protection Agency, state
  law and county ordinances)

4
Why are pesticides used in agriculture, society
and the environment?...continued

• 2. Society Environment
• a. Pesticides are used regularly in city parks
  and other recreational areas to control insect
  damage and weeds (ie Disneyland, ball parks,
  schools, etc)
• b. Pesticides are used to protect humans from
  insect-borne diseases, mosquitoes transmit many
  diseases (Mosquito Abatement Programs) West Nile
  Virus, Malaria
• c. Rodenticides are used in homes, restaurants
  and hotels to control mice and rats which can
  spread disease, Junta Virus

5
Concerns With Pesticide Use

• 1. Environmental concerns
• a. pesticides can kill beneficial insects and
  plants (non selective)
• b. pollution runoff of herbicides and
  insecticides into irrigation water and then into
  rivers - damages wildlife habitat
• c. cancer causing agents organophosphates
• d. disrupt the natural ecosystem and natural
  biodiversity
• e. creates chemical resistance insects
  particularly

6
Integrated Pest Management (IPM)

• Pest management that utilizes several strategies
  to control insects and other pests rather than
  strictly relying on chemical control.
• Four Components

7
Integrated Pest Management (IPM) Components

• 1. Pest identification important for proper
  pest control
• Confuse beneficial insects with harmful
• Pest thats on the plant may not be the one
  causing damage
• Damage may not even be caused by an insect (toxin
  or nutritional deficiency, weather damage etc.)

8
Integrated Pest Management (IPM) Components

• 2. Surveying for pests systematically check
  for pests and pest damage
• Pheromone traps
• Sweeping the field
• Random leaf, fruit and stem samples

9
Integrated Pest Management (IPM) Components

• 3. Encourage Beneficial Insect/Animal
  Populations
• Use milder chemicals or selective sprays that
  dont kill beneficial animals.
• Examples Barn Owl Nesting Boxes rodent
  control
• Predatory wasp populations fly control in
  poultry and dairy operations
• Natural insect enemies lady bugs, lace wings,
  praying mantis, predatory mites

10
Integrated Pest Management (IPM) Components

• 4. Control Action Guidelines
• Application of pesticides only after a certain
  number of pests have been found and there is a
  threat of economic loss.

11
Sociology of Pesticides

• Rachel Carlson (1962) beginning of the modern
  environmental movement - Silent Spring
• DDT pesticide Nobel Prize in medicine
• Insect/disease control - Potent toxin
• Still used to control mosquitoes in 3rd world
  countries
• Malaria, Yellow Fever, Dengue Fever spread by
  mosquitoes
• Yellow Fever nearly prevented the colonies from
  being settled
• More soldiers were lost in WWII due to mosquitoe
  borne disease than in battle.

12
Sociology of Pesticides continued

• Vietnam War used defoliants to clear forests
• Post War Conditions Refugee camps, many
  diseases
• Modern ChallengeDisease could be used as a
  weapon (biological and chemical agents)
• Bubonic Plague infected fleas dropped them on
  China during WWII killed 50,000 people
• Many people think all pesticides should be
  banned.
• San Francisco has tried to ban all pesticides
  this would include germ killers like Chlorine

13
Pesticide Routes of Entry

• Dermal (skin) most common
• Oral
• Respiratory
• Ocular

14
Pesticide Toxicological Tests

• U.S. food supply is the safest in the world
• Risk Cup EPA evaluate scientifically the
  level of risk compared to benefits.
• Fill the cup with all the risks an individual is
  exposed to during their lives.

15
Politics of Pesticides

• Environmental lobbyists are very powerful in
  Washington D.C.
• Natural Resource Defense Fund contracted with
  20/20 to break the story on Alar in apples
• -Alar was banned w/out scientific evidence.
• -Organo Phosphate, carbonate pesticides
  research based on WWII neurotoxicity studies.

16
Politics of Pesticides continued

• Biocides easily manufactured inexpensive
• Petroleum industry was the generator
• Pet pesticides flea control, tick control
• Pharmaceutical industry does much of the
  pesticide research today, patent lasts 17 years
  it takes 10 years to complete research process.
• How much does this cost?

17
Environmental Issues with Pesticides

• Pesticides enter the environment through crop
  application.
• Leach into aquifer
• Central Valley has potential problems associated
  with continual pesticide chemical.
• Problem-Bio-magnification

18
Bio-magnification

• Chlorodane killed lots of bugs, 30 year
  half-life, very stable in soil. Mis-application
  of insecticide caused it to be banned.
• DDT stays in the environment, organisms pick up
  the molecules and it stays in the animals
  tissuesanimals eat animals and it passes
  onRaptor egg shell thinness
• Resistance develops kill 99 1 left that are
  resistant. Survivals detoxify chemicals used as
  pesticides low kill-rate. Pesticide treadmill

19
Some Answers to Reducing Pesticide Use

• Control populations work within ecological
  principles, IPM
• Pest Control Advisors must use these practices,
  an old idea.
• Select all the techniques to control pests.
• Understand the ecological interactions of the
  pests.
• California has now made laws to regulate
  pesticides.

20
The Future Challenges?

• IPM requires people to work smarter dealing
  with biology ecology and utilizing
• Environmentally Friendly pesticides
• Mycotoxins aflatoxins naturally occurring
  toxins in peanuts, mushrooms
• Organic Farming now will be regulated by the
  federal government, fringe element no more.
• Biotechnology fear of the unknown, no risk is
  acceptable according to anti-biotech groups.

21
Future of Chemicals Pesticides

• Alternatives will be Key Issue
• Beneficial insects
• Mechanical control
• Chemical controls
• Hedgerows create a place for native species-
  self perpetuating
• Cover crops that produce nitrogenlower
  fertilizer use
• Cover crops that encourage beneficial insects...
• Proper irrigation for various cropsreduce runoff