54a Pesticides

5.4a Understand the reasons for pest control and the advantages and disadvantages of using pesticides with crop plants.



Pesticides:
Large fields of crops that are all of the same type of crop = Monoculture
Monocultures are very susceptible to pests. They use the crop as their food source. Which reduces the productivity of farming. = Loss of food and financial impact on the farmer.

1. Use Pesticides.
Pesticides are chemicals, designed to kill the pest.

Advantages:
1. Chemicals so are easy to obtain
2. Easy to apply (simply spray on crop)
3. Very effective

Disadvantages:
1. Many are toxic – possible kill other plants and animals
2. Bio accumulation – Pesticides builds up in the food chain causing harm to the food source in the higher tropic levels (eg DDT)
3. Mutation in the pest often leads to resistance, so the pesticide must be applied in high concentrations – therefore more toxic.