Detection and Identification of Plant Diseases (AQA GCSE Biology)

Revision Note

Test Yourself
Lára

Author

Lára

Expertise

Biology Lead

Plant Pathogens

  • Plants can be infected with a range of bacterial and viral pathogens; such as the tobacco mosaic virus (TMV) and rose black spot fungus (see Viral Diseases & Fungal Diseases)
  • Plants can also be infested with insects such as aphids
    • Aphids have long sharp mouthpieces that pierce the surface of the stem and into the phloem so that they can feed on the sugar filled sap
    • They can infest a plant in large numbers and remove large quantities of the phloem sap. This can weaken the plant
    • Aphids can also act as a vector for the transfer of diseases
    • Biological pest control (using ladybirds, a natural predator of the aphid) to feed on them or using chemical pesticides are the best ways to control infestation with aphids

Detecting Plant Diseases

Higher tier only

  • Infections in plants as with all organisms are better when detected and treated quickly
  • Symptoms of diseases in plants include:

Plant diseases table

Detecting Plant Diseases table 1, downloadable IGCSE & GCSE Biology revision notes

Identifying Plant Diseases

Higher tier only

  • The symptoms of plant diseases can apply to more than one disease, which makes identifying them difficult
    • Diseases in the garden can be identified by comparing symptoms to those described in gardening manuals or online
    • Crop plants or forest trees, experts may visit the field/woodland to take samples which can then be taken to a lab to undergo DNA analysis. This would help to identify the specific pathogen causing the problem
    • Plant scientists, foresters, farmers and market gardeners can use testing kits which contain monoclonal antibodies to identify the presence of pathogens quickly and easily

Mineral Deficiencies

  • Plants like all organisms need the correct amount of nutrients to function properly
  • If plants are deficient in a mineral these can be replaced by fertilisers added to the soil
  • These fertilisers are often shown as NPK ratios depending on the need of the plant that is being grown

Mineral deficiencies table

Mineral Deficiencies table 2, downloadable IGCSE & GCSE Biology revision notes

Exam Tip

Exam questions about mineral deficiencies may ask you to recommend a fertilizer based on the symptoms that the plant has.

You've read 0 of your 0 free revision notes

Get unlimited access

to absolutely everything:

  • Downloadable PDFs
  • Unlimited Revision Notes
  • Topic Questions
  • Past Papers
  • Model Answers
  • Videos (Maths and Science)

Join the 80,663 Students that ❤️ Save My Exams

the (exam) results speak for themselves:

Did this page help you?

Lára

Author: Lára

Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. Lára has a particular interest in the area of infectious disease and epidemiology, and enjoys creating original educational materials that develop confidence and facilitate learning.