B4.3.3.1

Detection and identification of plant diseases

Content

  1. (HT only) Plant diseases can be detected by:
  • stunted growth
  • spots on leaves
  • areas of decay (rot)
  • growths
  • malformed stems or leaves
  • discolouration
  • the presence of pests.
  • (HT only) Identification can be made by:
  • reference to a gardening manual or website
  • taking infected plants to a laboratory to identify the pathogen
  • using testing kits that contain monoclonal antibodies
  1. Plants can be infected by a range of viral, bacterial and fungal pathogens as well as by insects.
  2. Knowledge of plant diseases is restricted to tobacco mosaic virus as a viral disease, black spot as a fungal disease and aphids as insects.
  3. Plants can be damaged by a range of ion deficiency conditions:
    • stunted growth caused by nitrate deficiency
    • chlorosis caused by magnesium deficiency.
    • Knowledge of ions is limited to nitrate ions needed for protein synthesis and therefore growth, and magnesium ions needed to make chlorophyll.

WS 1.4

The everyday application of scientific knowledge to detect and identify plant disease.

Describe and explain specified examples of the technological applications of science. Describe and evaluate, with the help of data, methods that can be used to tackle problems caused by human impacts on the environment.