“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…
Integrated Pest Management (IPM) 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 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?