Of insect predation no need for modern p lants to

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Unformatted text preview: resources to disperse seeds - WE do this for them (via harvesting) -We supply water and N - no need for extensive resources to be a llocated to developing elaborate root systems -We eliminate the risk of insect predation - no need for modern p lants to spend resources on this either 4 3/25/2013 High Yielding Dwarf Varieties What’s the catch? HYV are very needy plants What’s the catch? HYV are very needy plants • These depend on exhaustible natural resources with limited supplies • Less needed, competition prevented by mechanized cultivation & herbicides; other selection reduced • These need fossil fuels (mostly oil, natural gas) • Less needed, supplied by irrigation & fertilizer • Less needed, competition prevented by mechanized cultivation & herbicides; other selection reduced • Less needed, supplied by irrigation & fertilizer • Less needed, protection conferred by insecticides & fungicides • Less needed, protection conferred by insecticides & fungicides 17 18 -We use natural resources to supply fertilizer to these plants -E.g. Oil and gas is needed to run the tractors responsible for large s cale farming -Insecticides hit other organisms -We are simultaneously imposing STRONG selection on pest p opulations -We create conditions that facilitate the fast evolution of resistance What’s the catch? HYV are very needy plants • These tend to pollute the environment, especially groundwater, and poison non target organisms • Also cause prompt evolution of resistance, loss of natural controls, therefore addictive What’s the catch? HYV are very needy plants • Less needed, competition prevented by mechanized cultivation & herbicides; other selection reduced • These lead to long term erosion or degradation of soils • Less needed, supplied by irrigation & fertilizer LOSS of topsoils • Less needed, protection conferred by insecticides & fungicides • Less needed, competition prevented by mechanized cultivation & herbicides; other selection reduced •...
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This document was uploaded on 01/27/2014.

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