B5.10 More about plant diseases Flashcards
What are aphids?
A group of insect plant pests
What do aphids do?
They have sharp mouthparts that penetrate into the phloem vessels of the plant so they can feed on the sugar rich phloem sap
What else can aphids do instead of depriving the plant cells of the products of photsynthesis?
Can act as vectors - transferring pathogens from diseases plants into the tissues of healthy plants on their mouthparts
How can aphids be destroyed?
Using chemical pesticides or using biological pest control such as ladybirds and larvae
Why do plants need nitrate ions?
To convert sugars made in photosynthesis into proteins needed for growth in protein synthesis
What happens if there is a nitrate deficiency in the soil?
Protein growth will be limited - the growth of plants will be stunted and they will not produce a crop properly
Why do plants need magnesium ions from the soil?
To make chlorophyll needed for photosynthesis
What happens if there is magnesium deficiency?
Leads to the plant not making enough chlorophyll - the leaves become yellow and growth slows down because the plant cannot photosynthesise properly
What is chlorosis?
The yellowing of the leaves due to lack of magnesium ions
What do symptoms of plant diseases include?
Stunted growth Spots on leaves Areas of decay Malformed stems Discoloration Presences of visible pests
How can plant diseases be identified?
By comparing the symptoms to gardening manuals and laboratory test - some involving monoclonal antibodies
