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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI 600 034 B.Sc.DEGREE EXAMINATION PLANT BIOLOGY AND PLANT BIOTECHNOLOGY FIFTH& SIXTH SEMESTER APRIL 2017
PB 5523 PB 6608 PLANT DISEASES MANAGEMENT
Date: 28-04-2017 Dept. No. Max. 100 Marks
01:00-04:00
PART A Answer the following, each within 50 words. (10 x 2 20 marks)
1. Comment on inoculum potential.
2. What are phytoalexins?
3. List the role of abscission in protection against disease.
4. What is induced resistance?
5. Mention the symptoms of damping off?
6. What is club root?
7. What is tungro?
8. Little leaf of brinjal?
9. What is plant quarantine?
10. What is alternate host? Give example.
Part b Answer the following, each within 500 words. Draw diagrams and flow charts wherever necessary. x 7 35 marks)
11.a. Describe Koch's postulates.
b. Write about the various methods of entry of fungi into plants.
12a. Write an account on cross protection.
b. Explain the role of environmental factors on disease development.
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13a. Write an account on tikka disease.
b. Describe the symptoms and control measures of red rot of sugarcane.
14a. Write an account on insect galls.
b. Write about any one nematode disease.
15a. Describe the importance of disease forecasting in plant disease management. b. Describe the various methods of seed treatment.
PART C Answer any three of the following, each within 1200 words. Draw diagrams and flow charts wherever necessary. x 15=45 marks)
16. Describe briefly about the structural defense mechanisms adopted by plants against pathogens.
17. Describe the role of suberin, lignin, phenols and gums in disease development.
18. Describe the disease cycle of paddy blast.
19. Write an essay on any two bacterial diseases in plants.
20. Write an essay on integrated pest and disease management in agriculture.