CROP PESTS (ACE1022)
Self-Test Questions
General plant pathology
- What kinds of organisms can cause plant diseases?
- What are the three key criteria of successful disease control?
- What is the difference between
'symptoms' and 'signs'?
- Define 'biotrophic' and 'necrotrophic'.
- What is the structure by which many biotrophic pathogens obtain their nutrients from plant cells?
- How do necrotrophic pathogens damage plants?
- Why does host uniformity increase the danger of disease epidemics?
- What are the four stages of the typical infection cycle?
- What is the significance of whether one or many cycles of a disease occur in a growing season?
- What are three mechanisms by which fungal pathogens are dispersed?
- What is the major mechanism by which viral pathogens are dispersed?
- What are the key environmental factors that influence the development of plant diseases?
- What is the use of trying to predict disease severity?
- How can pathogens be excluded?
- Why is it sometimes useful to grow plants where a pathogen is absent?
- List three cultural practices for minimising initial inoculum.
- What was the first successful chemical for plant disease control?
- Why are systemic fungicides in general preferable to protectant fungicides?
- But what is the major problem with systemic fungicides?
- And are there any ways to reduce this problem?
- What are the principal mechanisms by which plants resist diseases?
- What are
'major-gene' and 'polygenic' resistance, and what are their respective advantages and disadvantages?
- Why is biological control not more widely used?
- How can genetic engineering be used to control plant viruses?
- In what ways do oomycetes differ from 'true' fungi?
- In what ways do basidiomycetes differ from ascomycetes?
Specific diseases
- What is the name of the pathogen that causes the disease?
- How can the disease be recognised, and how does it affect the plant (signs and symptoms)?
- How does the pathogen spread from plant to plant?
- How does the pathogen survive in the absence of living host material?
- How is the disease controlled?
- Powdery mildew of cereals
- Septoria blotch of wheat
- Scald of barley
- Take-all of wheat
- Rusts of cereals
- Potato late blight