LECTURE 9 “CROP PROTECTION” AKA PESTICIDE USE

jamaicanabsorbingBiotechnology

Dec 5, 2012 (5 years and 1 month ago)

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“CROP PROTECTION”
PESTICIDE USE

AGST 3000

Agriculture, Society and the Natural World

Some Definitions


Crop Protecting Agent

= A politically correct
term for Pesticides.

Pesticide = a substance that kills a pest
(insect, weed, bacteria, nematode…)



1. Herbicide = plant killer



2. Insecticide = insect killer



3. Rodenticide = rodent killer


Other “cides”??

Why are pesticides used in agriculture
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 (Pierce’s Disease)


c. The use of pesticides is regulated by the E.P.A.
(Environmental Protection Agency), State law
and County regulation)

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

2.
Society & Environment:


a. Aesthetics
-

used regularly in city parks and
other recreational areas to control insect
damage and weeds (ie Disneyland, ball parks,
schools, etc)



b. Protect humans from insect
-
borne diseases,
mosquitoes transmit many diseases (Mosquito
Abatement Programs) West Nile Virus, Malaria.




c. Protect our food supply. In developing
countries (India), up to 1/3 of all harvested
grain is destroyed by rodents and insects.




Concerns With Pesticide Use

1.
Environmental concerns


a. They kill beneficial insects and plants (non
selective).


b. Pollution


runoff of herbicides and
insecticides into irrigation water and then into
rivers
-

damages wildlife habitat, kills fish.


c. Cause cancer


organophosphates


d. Disrupt the natural ecosystem and natural
biodiversity


e. Creates chemical resistance


insects and
weeds. Examples?

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…

1. Pest identification



important for proper pest
control





Confuse beneficial
insects with harmful
(not all bugs are bad!)





Pest that’s on the plant
may not be the one
causing damage.





Damage may not even
be caused by an insect
(herbicide or
nutritional deficiency,
weather damage etc.)

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

Integrated Pest Management (IPM) Components

Integrated Pest Management (IPM) Components

3. Encourage Beneficial Insect/Animal
Populations



Use milder chemicals or selective sprays that
don’t 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

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.

A Little History….


Early pesticides were developed from
neurotoxins researched for germ
-
warfare
in WWI and WWII.


DDT (Dichloro
-
diphenyl
-
trichloroethylene)


1948 Paul Herman Mueller was awarded
the Nobel Prize in medicine for his
research on the benefits of DDT.


After WWII DDT was used in agriculture.

The Environmental Movement


Rachel Carlson (1962)


beginning of the modern
environmental movement, created an awareness
of the damage pesticides were causing on the
environment with her book


“Silent Spring”


Near loss of the Bald Eagle and many fish
-
eating
birds was attributed to DDT.


DDT


An example of an effective pesticide!


Insect/disease control
-

Potent toxin, long half
-
life


Still used to control mosquitoes in developing 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 mosquito
-
borne
disease than in battle.


Sociology of Pesticides
continued…



Vietnam War


used defoliants to clear forests



Post War Conditions


Refugee camps, many diseases



Modern Challenge…Disease 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


Pesticide Routes of Entry



Dermal (skin) most common




Oral




Respiratory




Ocular

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.

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?

Environmental Issues with Pesticides


Pesticides enter the environment through crop
application.



Leach into aquifer



Drift from applying during wind



Improper usage and disposal of containers



Central Valley has potential problems associated
with continual pesticides and chemical
applications. WHY?



Problem
-
“Bio
-
magnification”

“Bio
-
magnification”


Duration
…Chlorodane


killed lots of bugs, 30
year half
-
life, very stable in soil. Improper
application of insecticide caused it to be banned.



Accumulation
…DDT


stays in the environment,
organisms pick up the molecules and it stays in
the animal’s tissues…animals eat animals and it
passes on…Raptor egg shell thickness



Resistance

develops


kill 99%; 1% left that are
resistant. Survivals detoxify chemicals used as
pesticides low kill
-
rate. “Pesticide treadmill”

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.


More is not necessarily better…follow application
guidelines strictly



California has the strictest rules and regulations
concerning pesticides in the nation.


Pesticide Regulations used in
California Agriculture


ALL pesticide applicators must have a license
which they obtain by successfully taking a test.
“Private Applicator’s License”


CE is required to maintain the license.


ALL Farm workers must use proper safety
equipment


mask, gloves, safety glasses,
coveralls. Must be trained in their native
language.


Pesticide storage is monitored by the state
government. County Health Dept.


Hazardous
materials, pay a fee annually.


Pesticide Regulations used in
California Agriculture


All pesticide run
-
off must be contained.


All farmers using pesticides must complete
a NOI (Notice of Intent) with the county in
order to apply ANY pesticide (even Round
-
Up). WHY?


Who monitors agriculture? What are the
consequences for violators??


Organic Foods


Promoted as being
“Healthier” because
they’re farmed
without the use of
pesticides right??


Wrong!


organic
farmers use
pesticides! What’s the
difference?


Examples?

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.



Future of Chemicals & Pesticides

Alternatives will be Key Issue…not a new
concept!



Beneficial insects


Mechanical control


Chemical controls


Hedgerows


create a place for native species
-

self perpetuating


Cover crops that produce nitrogen…lower
fertilizer use


Cover crops that encourage beneficial insects...


Proper irrigation for various crops…reduce
runoff

Journal


What do you think are some of the greatest threats to
using pesticides..?



In California


In the US


Globally



What are some of the greatest benefits you see from
using pesticides?



Do you feel that we can ever live without
pesticides/chemicals? Why, Why not?



Do you think that we have a tendency to overreact in
California and are our laws and regulations justified?