BIOB38H3 Lecture Notes - Lecture 5: Bt Cotton, Crop Diversity, Wild Type
Document Summary
Ecological negative effects of the gr: loss of crop diversity, negative effects of pesticides, unsustainable soil, unsustainable water use, unsustainable fossil fuel use. If we don"t do anything, we would lose 75% of our harvest. We reduced loss to 30% by using pests. China uses pests the most: need pesticides to reduce harvest loss. In the 50s we used the first type of chemicals to attack potato beetles. Case for pesticides: kill beneficial organisms/wildlife, water contamination; worker safety, development of resistance by organisms, < 2% of aerial pesticides reach target pests, more pests around after spraying then before, removing organisms that eat pests. Save humans from disease/poisoning: work faster and efficiently, no sorting mechanism to remove weeds, new pesticides safer and more diverse, defense evolves in response to selection, but it reduces growth rates and reproductive outputs. If there"s no threat, there"s reduced defense and less fitness.
