What are the pros and cons of pesticide use?

Pros- Cons-

1. kills insects 1. Threaten human health

2. kills weeds 2. Pollute ecosystems

3. kills other pests that 3. Promote the evolution destroy crops of pest resistance

Agriculture

• Development of Agriculture– Hunter-gatherers would bring fruit, grains and

nuts to camps– Food fell, seeds of plants they liked began

growing nearby– Began breeding plants with characteristics they

wanted– Selective breeding began– People became settled in these areas to harvest

crops

Traditional vs. Industrial Agriculture• Traditional– All farming by human and animal power alone– Hand tools and non-motorized machines– Doesn’t require fossil fuels

• Industrial– Replaced horses and oxen with machines to farm faster

and more efficiently – Requires high-input agriculture lots of energy needed– Introduction of pesticides and synthetic fertilizers

• Increased productivity of soil• Yields increased

– Efficient to plant monocultures

• Scientists of developed nations introduced new technology, crop varieties, and farming practices to the developing world

• Fed millions of people• Energy increased by 7000%• Intensive application of water, fertilizers and

pesticides worsened erosion• Fossil fuels increased air pollution global warming• Preserved some ecosystems– Less land needed to be cleared for crops– Prevented deforestation and preserved biodiversity

• Saved lives at an environmental cost

Pests

• Chemical pesticides– Leveled off in developed countries– Evolutionary arms race• Pest population evolves a resistance to the pesticide• Must increase toxicity to kill pests

• Biological pest control– Kill pests with organisms that eat or infect them– Led to reductions in pesticide use• Parasitoid wasps and caterpillars

– Environmentally harmless, no maintenance– Invasive species, may kill nontarget organisms

Integrated Pest Management

• Different techniques are combined to achieve most effective pest reduction

• May include biological pest control, close monitoring, habitat alteration

Pollinators

• Animals that help the process of male sex cells (pollen) fertilizing female sex cells of plants

• Pollinator populations have declined– Pesticides are a cause– Also reduces the plants that benefit from the

pollinators• Pollinator conservation– Reduce or eliminate pesticide use or use

pheromone traps that pollinator-safe alternatives

Food Production

• If human population expands, we need to increase agricultural production

• Cannot do this because arable land (suitable for farming) will run out

Food Security• Increased food production by:– Increasing energy– Planting and harvesting frequently– Increasing irrigation, fertilizers, and pesticides– Increasing cultivated land– Developing more productive crops and livestock

• Food security – guarantee adequate and reliable food supply for all people at all times– Maintain healthy soil and water– Protect biodiversity– Safe distribution of food

Undernourished vs. Malnourished

• Undernourished – Get <90% of daily calories needed– Normally from economic reasons

• Malnourished– Shortage of nutrients– Causes bloating of abdomen, skin problems,

lowered immunity