Plant Diseases Flashcards
All 6 cards in this deck
Name three ways a plant disease can be detected and identified in the field.
Observing visible symptoms, distribution analysis of affected plants, and eliminating possible environmental causes.
What is distribution analysis in the detection of plant disease?
Looking at where the affected plants are: spread outwards from one point suggests an infectious pathogen, while even damage across a whole area suggests an environmental cause.
Give three visible symptoms that suggest a plant is diseased.
Stunted growth, spots or discolouration on leaves, rotting/malformed stems or leaves (also visible pests).
Name two laboratory diagnostic tests used to identify a plant pathogen.
DNA analysis (e.g. PCR) of the pathogen's genetic material, and antibody test kits (monoclonal antibodies) that detect the pathogen's antigens.
True or false? Yellow leaves on a plant always mean it has been infected by a pathogen.
False. Environmental causes such as mineral deficiency or lack of water must be eliminated first.
What are the steps to work out the cause of disease in a crop in the field?
e.g. patches of wheat with yellow, spotted leaves
- Observe the visible symptoms: yellowing and leaf spots.
- Eliminate environmental causes: check minerals and water supply.
- Analyse the distribution and send a sample for lab diagnostic testing: spreading patches suggest a pathogen.