MCQ on Plant disease epidemiology
Plant Pathology MCQ E-Books Download1. Epidemiology in plant pathology is primarily the study of:
A. Pathogen reproduction
B. Host immunity
C. Disease outbreaks, intensity, causes, and effects
D. Crop yields
Answer: C
2. A disease that occurs consistently in a specific area over time is termed as:
A. Epidemic
B. Endemic
C. Pandemic
D. Sporadic
Answer: B
3. Citrus canker in Asia is an example of:
A. Epidemic disease
B. Sporadic disease
C. Endemic disease
D. Pandemic disease
Answer: C
4. A sudden, severe outbreak of a disease over a widespread area is classified as:
A. Endemic
B. Sporadic
C. Epidemic
D. Pandemic
Answer: C
5. The black stem rust outbreak of wheat in India during 1947 is an example of:
A. Endemic disease
B. Epidemic disease
C. Pandemic disease
D. Sporadic disease
Answer: C
6. A disease that occurs irregularly in limited areas is referred to as:
A. Sporadic
B. Pandemic
C. Endemic
D. Epidemic
Answer: A
7. The essential factors governing a plant disease epidemic are:
A. Soil, temperature, and water
B. Host, pathogen, and environment
C. Climate, fertilizer, and pesticide
D. Genetics, sunlight, and humidity
Answer: B
8. Which of the following is an example of a seasonal or annual epidemic?
A. Wart disease of potato
B. Phytophthora wilt of betelvine during the rainy season
C. Late blight of potato in Europe
D. Panama wilt of banana
Answer: B
9. An epidemic resulting from the introduction of a new pathogen is characterized by:
A. High susceptibility of existing hosts
B. Lack of aggressive pathogen strains
C. Rapid equilibrium with local pathogens
D. Inability to cause severe damage
Answer: A
10. Which pathogen is responsible for the seasonal epidemic in arecanut during the monsoon period?
A. Phytophthora infestans
B. Phytophthora arecae
C. Puccinia graminis
D. Pyricularia oryzae
Answer: B
11. The susceptibility of a host depends on:
A. Nature, environment, and growth stage of the plant
B. Climate, soil pH, and nutrient availability
C. Pathogen type, host abundance, and sunlight
D. Plant immunity, pest levels, and nitrogen content
Answer: A
12. Late maturing varieties of wheat are more susceptible to:
A. Loose smut
B. Black rust
C. Leaf spot
D. Powdery mildew
Answer: A
13. Which environmental factor makes rice plants more susceptible to blast disease?
A. High humidity
B. Application of heavy doses of nitrogen fertilizers
C. Low temperature
D. Reduced sunlight
Answer: B
14. Continuous cultivation of susceptible crops in a large area leads to:
A. Reduced pathogen propagation
B. Increased risk of epidemics
C. Decreased disease cycles
D. Complete eradication of diseases
Answer: B
15. What is the role of environmental factors in plant disease epidemics?
A. They provide immunity to plants
B. They create conditions favorable for pathogen growth and spread
C. They prevent the establishment of pathogens
D. They delay the disease cycle
Answer: B
16. The pathogen responsible for Panama wilt in banana is:
A. Colletotrichum falcatum
B. Phytophthora arecae
C. Fusarium oxysporum f.sp. vasinfectum
D. Puccinia graminis
Answer: C
17. Seasonal epidemics often occur because of:
A. Year-round pathogen activity
B. Pathogen dormancy during unfavorable conditions
C. Lack of susceptible hosts
D. Rapid pathogen mutation
Answer: B
18. What is a key characteristic of epidemic diseases compared to endemic ones?
A. Consistent low-level presence
B. Irregular widespread outbreaks
C. Limited geographic occurrence
D. Involvement of mild pathogens
Answer: B
19. Which factor is NOT essential for a plant disease epidemic?
A. Susceptible hosts
B. Favorable environmental conditions
C. Genetic diversity of crops
D. Presence of an aggressive pathogen
Answer: C
20. The spread of wheat black rust in the U.S.A. and Canada is largely due to:
A. Strong pathogen resistance in wheat
B. Large contiguous areas of wheat cultivation
C. Introduction of disease-resistant wheat varieties
D. Lack of pathogen dispersal mechanisms
Answer: B
21. Which of the following is the primary factor for a plant disease to be classified as epidemic?
a) Host susceptibility
b) Introduction of a new pathogen
c) Favorable environmental conditions
d) High birth rate of the pathogen
Answer: c) Favorable environmental conditions
22. What is the term used to describe a disease that occurs more or less constantly year after year in a moderate to severe form in a specific locality?
a) Epidemic
b) Endemic
c) Pandemic
d) Sporadic
Answer: b) Endemic
23. A disease that causes widespread destruction in a short time due to favorable environmental conditions is called:
a) Endemic
b) Sporadic
c) Epidemic
d) Pandemic
Answer: c) Epidemic
24. Which of the following is an example of an epidemic disease?
a) Wart disease of potato
b) Citrus canker in Asia
c) Wheat stem rust
d) Loose smut of wheat
Answer: c) Wheat stem rust
25. Which of the following is a characteristic of a pandemic?
a) Occurs in a small area
b) Causes mass mortality across continents
c) Affects only one species of plant
d) Occurs in sporadic intervals
Answer: b) Causes mass mortality across continents
26. Which of the following is a key factor in the development of epidemics in plant diseases?
a) Host factors only
b) Pathogen factors only
c) Environmental factors only
d) All of the above
Answer: d) All of the above
27. What is the impact of introducing a new collateral or alternate host on plant disease epidemics?
a) It can reduce the spread of pathogens
b) It leads to increased inoculum production for the next crop
c) It decreases pathogen multiplication
d) It prevents the pathogen from spreading
Answer: b) It leads to increased inoculum production for the next crop
28. What is a major consequence of introducing a new exotic cotton variety in a region where it is not native?
a) Reduced pathogen spread
b) Increased resistance to local diseases
c) Outbreaks of bacterial blight and grey mildew
d) No impact on disease outbreaks
Answer: c) Outbreaks of bacterial blight and grey mildew
29. What is meant by the term “pathogenic factors” in plant disease epidemiology?
a) Factors related to the host’s immune system
b) Factors associated with pathogen characteristics
c) Factors influenced by weather conditions
d) Factors related to soil health
Answer: b) Factors associated with pathogen characteristics
30. What is a typical feature of aggressive strains of pathogens?
a) Slow cycle of infection
b) High mortality rates
c) Low reproductive capacity
d) Rapid cycle of infection and spread
Answer: d) Rapid cycle of infection and spread
31. What does the fecundity of a pathogen refer to?
a) The number of hosts infected
b) The reproductive capacity of the pathogen
c) The environmental conditions required for infection
d) The mortality rate of the pathogen
Answer: b) The reproductive capacity of the pathogen
32. Which of the following pathogens is known for producing enormous amounts of spores, aiding in rapid epidemic spread?
a) Fusarium oxysporum
b) Puccinia graminis tritici (wheat stem rust)
c) Erwinia amylovora (fire blight)
d) Ceratocystis ulmi (Dutch elm disease)
Answer: b) Puccinia graminis tritici (wheat stem rust)
33. How does the pathogen spread in diseases with high birth rates?
a) Only by root contact
b) Primarily through insect vectors
c) Through airborne spores and rapid dissemination
d) Through water-based transmission
Answer: c) Through airborne spores and rapid dissemination
34. What environmental factor is essential for the rapid spread of pathogens in epidemics?
a) Soil pH
b) Wind, water, and humidity
c) Crop rotation practices
d) Fertilizer type
Answer: b) Wind, water, and humidity
35. In compound interest diseases, how is the rate of increase of the pathogen described?
a) Linear
b) Exponential
c) Analogous to compound interest
d) Analogous to simple interest
Answer: c) Analogous to compound interest
36. What characterizes simple interest diseases in plant pathology?
a) The pathogen produces a new generation in a single growing season
b) The disease shows exponential growth within one season
c) There is only one generation of the pathogen during the crop’s life cycle
d) Secondary spread is common within the growing season
Answer: c) There is only one generation of the pathogen during the crop’s life cycle
37. Which of the following is an example of a simple interest disease?
a) Powdery mildew
b) Wheat stem rust
c) Loose smut of wheat
d) Late blight of potato
Answer: c) Loose smut of wheat
38. What happens in compound interest diseases during the crop growing season?
a) Only primary inoculum is involved
b) Pathogen multiplication and secondary infection happen rapidly
c) The disease remains localized and doesn’t spread
d) The pathogen is only seed-borne
Answer: b) Pathogen multiplication and secondary infection happen rapidly
39. What is the role of environmental factors such as temperature and moisture in disease epidemics?
a) They have minimal effect on disease development
b) They influence spore germination, infection, and establishment of pathogens
c) They only affect the host’s resistance
d) They prevent the pathogen from spreading
Answer: b) They influence spore germination, infection, and establishment of pathogens
40. What is an example of a compound interest disease?
a) Fusarium wilt
b) Root rot
c) Powdery mildew
d) Soil-borne smut
Answer: c) Powdery mildew