2/18/2012

5.4- Pesticides and Biological Control

understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants
Monoculture: 
  • Large fields with the same type of crops
  • Susceptible to pests (variety of living things)--> reduces productivity of farming--> loss of food and financial impact on farmer
  • Pesticides- Chemical and are designed to kill a pest
    • Advantages:
      • Chemicals --> Easy to obtain
      • Easy to apply
      • Very effective
    • Disadvantages:
      • Very toxic- harmful to humans
      • Bio accumulation
      • Mutation in the pest leads to resistance
        • Pesticides may not work/ may need to be applied in a higher concentration
Biological Control: 
  • Cactus flourished in Australia but there were no natural predators of it
  • It needed to be removed as it was taking up agricultural land
  • Moth (Cactoblastis) was introduced from another country (Alien species)
    • Advantages:
      • No toxic chemicals involved
      • Less impact on humans and wildlife
    • Disadvantages:
      • Not 100% effective
      • Difficult to control
      • A danger that an alternative food source might be found for the alien species
      • Sometimes difficult to match a predator to the prey

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