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Presentation on theme: "PROTECTING FOOD RESOURCES: PEST MANAGEMENT"— Presentation transcript:

Organisms found in nature (such as spiders) control populations of most pest species as part of the Earth’s free ecological services.

We use chemicals to repel or kill pest organisms as plants have done for millions of years. Chemists have developed hundreds of chemicals (pesticides) that can kill or repel pests. Pesticides vary in their persistence. Each year > 250,000 people in the U.S. become ill from household pesticides.

Advantages and disadvantages of conventional chemical pesticides.

4 Individuals Matter: Rachel Carson
Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment.

5 The Ideal Pesticide and the Nightmare Insect Pest
The ideal pest-killing chemical has these qualities: Kill only target pest. Not cause genetic resistance in the target organism. Disappear or break down into harmless chemicals after doing its job. Be more cost-effective than doing nothing.

6 Superpests Superpests are resistant to pesticides.
Superpests like the silver whitefly (left) challenge farmers as they cause > $200 million per year in U.S. crop losses.

7 Pesticide Protection Laws in the U.S.
Government regulation has banned a number of harmful pesticides but some scientists call for strengthening pesticide laws. The EPA, the Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.

8 Reducing Exposure to Pesticides
What Can You Do? Reducing Exposure to Pesticides • Grow some of your food using organic methods. • Buy organic food. • Wash and scrub all fresh fruits, vegetables, and wild foods you pick. Figure 13.30 Individuals matter: ways to reduce your exposure to pesticides. QUESTION: Which two of these actions do you think are the most important? • Eat less or no meat. • Trim the fat from meat.

9 Other Ways to Control Pests
There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. Fool the pest through cultivation practices. Provide homes for the pest enemies. Implant genetic resistance. Bring in natural enemies. Use pheromones to lure pests into traps. Use hormones to disrupt life cycles.

10 Other Ways to Control Pests
Biological pest control: Wasp parasitizing a gypsy moth caterpillar.

11 Other Ways to Control Pests
Genetic engineering can be used to develop pest and disease resistant crop strains. Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage.

12 Case Study: Integrated Pest Management: A Component of Sustainable Agriculture
An ecological approach to pest control uses a mix of cultivation and biological methods, and small amounts of selected chemical pesticides as a last resort. Integrated Pest Management (IPM)

13 Case Study: Integrated Pest Management: A Component of Sustainable Agriculture
Many scientists urge the USDA to use three strategies to promote IPM in the U.S.: Add a 2% sales tax on pesticides. Establish federally supported IPM demonstration project for farmers. Train USDA personnel and county farm agents in IPM. The pesticide industry opposes such measures.

Three main ways to reduce hunger and malnutrition and the harmful effects of agriculture: Slow population growth. Sharply reduce poverty. Develop and phase in systems of more sustainable, low input agriculture over the next few decades.

15 Solutions Organic Farming
Improves soil fertility Reduces soil erosion Retains more water in soil during drought years Uses about 30% less energy per unit of yield Lowers CO2 emissions Reduces water pollution from recycling livestock wastes Figure 13.34 Solutions: environmental benefits of organic farming over conventional farming based on 22 years of research comparing these two systems at the Rodale Institute in Kutztown, Pennsylvania (USA). QUESTION: Which two of these benefits do you think are the most important? (Data from Paul Mader, David Dubois and David Pimentel, et al.) Eliminates pollution from pesticides Increases biodiversity above and below ground Benefits wildlife such as birds and bats

16 Solutions: Making the Transition to More Sustainable Agriculture
More research, demonstration projects, government subsidies, and training can promote more sustainable organic agriculture.

17 Sustainable Organic Agriculture
What Can You Do? Sustainable Organic Agriculture • Waste less food • Eat less or no meat • Feed pets balanced grain foods instead of meat • Use organic farming to grow some of your food Figure 13.35 Individuals matter: ways to promote more sustainable agriculture. QUESTION: Which three of these actions do you think are the most important? • Buy organic food • Eat locally grown food • Compost food wastes


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