B5.10 More About Plant Diseases (Finished) Flashcards
How are plants infected with diseases?
Through viral, bacterial, and fungal pathogens as well as insect pests
What can non-communicable plant diseases be caused by?
- mineral deficiencies in the soil
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How can plant diseases be detected
- Identifying symptoms (e.g. Stunted growth, yellow spots)
- Garden manuals (comparison)
- Laboratory tests (in the field)
- Using testing kits that detect the presence of certain pathogens
How can insect pests affect plants?
Insect pests can both destroy plants directly and act as a vector of a disease
What are aphids?
Aphids are an important group of plant pests that have sharp mouthparts to penetrate into the phloem vessels to feed on sugar-rich sap
Why do aphids cause problems to plants?
Aphids attack in huge numbers depriving the plant cells of the products of photosynthesis which can seriously damage and weaken the plant. Also act as vectors
How can aphids be defended against?
They can be destroyed using chemical pesticides or biological pest control (releasing aphid eating insects)
How does a lack pf nitrate ions in the soil affect plants?
A lack of nitrate ions from the soil causes the growth of plants to be stunted as they need them to convert sugars made in photosynthesis into proteins needed for growth
How can a lack of magnesium ions in the soil affect plants?
Plants take magnesium ions from the soil to make the chlorophyll needed for photosynthesis. Not enough, less chlorophyll, leaves become yellow, growth slows, less photosynthesis
Hat is chlorosis?
Chlorosis is the yellowing of leaves due to a lack of magnesium ions in the soil
What are some symptoms of diseases in plants?
- Stunted growth
- Spots on leaves
- areas of decay/rotting
- growths
- malformed stems and leaves
- discolouration
- presence of visible pests
