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12-4 How Can We Protect Crops from Pests More Sustainably? Concept 12-4 We can sharply cut pesticide use without decreasing crop yields by using a mix.

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Presentation on theme: "12-4 How Can We Protect Crops from Pests More Sustainably? Concept 12-4 We can sharply cut pesticide use without decreasing crop yields by using a mix."— Presentation transcript:

1 12-4 How Can We Protect Crops from Pests More Sustainably? Concept 12-4 We can sharply cut pesticide use without decreasing crop yields by using a mix of cultivation techniques, biological pest controls, and small amounts of selected chemical pesticides as a last resort (integrated pest management).

2 Nature Controls the Populations of Most Pests What is a pest? Any species that _________________ with human welfare Worldwide, only about _______ species cause most of the damage to the crops we grow Many potential pests are controlled by ___________ ____________________ Example : Spiders kill far more insects than humans do every year with chemicals interferes 100 natural enemies

3 Natural Capital: Spiders are Important Insect Predators Fig. 12-21, p. 297 Wolf Spider Not dangerous to humans What will happen if pesticides kill off the wolf spiders in an area? Their prey population will increase

4 We Use Pesticides to Try to Control Pest Populations (1) Different types of pesticides include… Insecticides – _______________ killers Herbicides – ________________ killers Fungicides – _______________ killers Rodenticides – _________________ killers We are not the first species to use chemicals to ward off another… Plants have been doing this for nearly 225 million years insect weed fungus rodent

5 We Use Pesticides to Try to Control Pest Populations (2) First-generation pesticides – mainly natural chemicals borrowed from _____________ Farmers started using these back in the 1600s Second-generation pesticides – first used in 1939 _____________ produced: DDT and others Broad-spectrum agents – toxic to ___________ pests as well as many beneficial species narrow-spectrum agents – effective against ______________ group of organisms Persistence varies…length of time that they __________ in the environment plants Lab many narrow remain

6 Rachel Carson, Biologist Fig. 12-B, p. 298 Biologist Silent Spring Potential threats of uncontrolled use of pesticides

7 Modern Synthetic Pesticides Have Several Advantages Save human lives by preventing the transmission of _________________ Malaria = mosquito Bubonic plaque = rat fleas Increases food ___________ and ____________ for farmers…prevent crop loss Work _________________ When used properly, health risks are _________ relative to benefits New pesticides are much ___________ and more effective than older ones diseases supplies profit quickly low safer

8 Modern Synthetic Pesticides Have Several Disadvantages (1) Accelerate rate of genetic ________________ in pests ___________________ for farmers Some insecticides kill _____________ predators and parasites that help control the pest population ________________ in the environment; __________ wildlife; some are human health _______________ resistance Expensive natural Pollutionharms hazards

9 Pesticide Use Has Not Reduced U.S. Crop Losses to Pests David ________________: expert on insect ecology Studied data from more than 300 agricultural scientists and economists 1942-1997: crop losses from insects ______________ from 7% to 13%, even with _______ increase in pesticide use High environmental, health, and social costs with use Recommends using _____________________ pest management practices Pesticide industry _______________ these findings Pimental increased 10 x alternative disputes

10 What Can You Do? Reducing Exposure to Pesticides Fig. 12-23, p. 300

11 Laws and Treaties Can Help to Protect Us from the Harmful Effects of Pesticides Several U.S. federal agencies regulate the sale and use of pesticides Environmental Protection Agency ________ United States Department of Agriculture ___________ Food and Drug Administration _______ Laws and Treaties Federal Insecticide, Fungicide and Rodenticide Act, 1947 ____________ Assesses the health risks of active ingredients in pesticides Not properly funded…has only tested about _________ EPA USDA FDA FIFRA 10%

12 Laws and Treaties Can Help to Protect Us from the Harmful Effects of Pesticides Laws and Treaties Continued.. Food Quality Protection Act, 1996 Reduces the allowed levels of pesticide residues in food by ______ when the effects on ______________ are not well known 1998 International Treaty Signed by 50 countries Requires exporting countries to have informed __________ from importing countries for a list of 22 pesticides and 5 industrial chemicals 2000 International Treaty signed by 100 countries to ban or phase out 12 especially hazardous ____________ (persistent organic pollutants) 10% children consent POPs Stockholm Convention Rotterdam Convention

13 There Are Alternatives to Using Pesticides (1) ___________ the pest Crop rotation; changing planting times Provide homes for pest _______________ Requires plant diversity or _________________ Use _______________ engineering to develop pest and disease resistant crop strains Fool predators polycultures genetic

14 There Are Alternatives to Using Pesticides (2) Bring in natural enemies - predators, parasites, diseases Use insect perfumes or __________________ to lead pests into traps Bring in hormones that interfere with pest ___________ cycle Alternative methods of weed control Crop rotation, cover crops, mulches pheromones life

15 Integrated Pest Management Is a Component of Sustainable Agriculture Integrated pest management _________ Controlled program that uses a ________________ of cultivation, biological controls, and chemical tools to reduce crop damage to an economically tolerable level Reduces ________________ and ____________ costs Disadvantages Requires expert _________________ High _________________ costs Government and pesticide company opposition IPM collaboration pollution pesticide knowledge initial

16 12-5 How Can We Improve Food Security? Concept 12-5 We can improve food security by creating programs to reduce poverty and chronic malnutrition, relying more on locally grown food, and cutting food waste. Agriculture is a financially __________ business A good or bad year may depend upon… - Weather - Loan interest rates - Crop prices - global markets - Crop pests risky

17 Use Government Policies to Improve Food Production and Security Governments use two main approaches to influence food production 1.________________ prices to make food affordable Place an upper limit on prices Good for ____________________ but not for the farmer 2.Provide __________________ to farmers Tax breaks or other financial support to keep them in business and encourage food production Control consumers subsidies

18 Examples of Using Subsidies In __________________ the government provided small rural farmers access to… Seeds Tools Irrigation systems Storage facilities Positive Outcomes - Food production and jobs increase Negative Outcomes  - Sometimes more food is produced than can be sold….____________ of resources Kenya waste

19 Similarly, government subsidies to fishing fleets can promote ___________________ and the reduction of aquatic biodiversity Bottom trawling industries were provided $150 million in subsidies per year Many analysts are calling for an ___________ to these subsidies or only providing subsidies for farmers/fishers who use ______________________ methods overfishing end sustainable

20 Example: In 1984, ____________________ ended farm subsidies As a result, farmers had to become more __________________ and production of some foods such as milk ____________________________ New Zealand innovative quadrupled

21 Other Government and Private Programs are Increasing Food Security Government programs that reduce _____________ or _______________ population growth, also help to promote food security UN World Food Program created a new system for buying food from ________________ farmers to increase their economic security UNICEF studies indicate that 1/2 to 2/3 of nutrition related childhood deaths could be prevented with a small _____________ cost per child Immunizing children against childhood diseases Prevent dehydration in infants and children Vitamin A capsules poverty slow small $5-10

22 Global Crop Diversity Trust – storing _____________ to prevent the disappearance of the variety of our food crops Working with 50 gene banks around the world seeds

23 Review Questions What are some examples of different types of pesticides? What has been the goal of recent international treaties regarding pesticide transfer and use? What is the goal of IPM? Insecticides, herbicides, fungicides, rodenticides To require informed consent and ban certain POPs To reduce both crop damage and pollution at economically tolerable levels

24 Review Questions What are the two main approaches used by governments to influence food production? What are some examples of different organizations that are helping to improve food security? Control prices Provide farmer subsidies UN World Food Program UNICEF Global Crop Diversity Trust


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