LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & BIOTECHNOLOGY

IB 24

SIXTH SEMESTER – APRIL 2006

                                        PB 6604 – PLANT DISEASES AND MANAGEMENT

(Also equivalent to PB 5501)

 

 

Date & Time : 19-04-2006/FORENOON     Dept. No.                                                       Max. : 100 Marks

 

 

Part – A

 

Answer the following                                                                                     (20 marks)

 

I Choose the best answer                                                                                (5 ´ 1 = 5)

 

1. Cork layers are produced due to the infection by
2. Prunus domestica b. Nicotiana tobaccum c. Oryza sativa d. Triticum aestivum

 

2. Die back disease of citrus caused by the deficiency of
3. Mg b. K                 c. N                 d. Cu

 

3. Uredospores of Puccinia graminis are
4. Two celled, uninucleated b. One celled, binucleated
5. Two celled, binucleated d. One celled, uninucleated

 

4. The term infestation is associated with:
5. Viruses b. Bacteria       c. Fungi           d. Insects

 

5. Topical fungicides applied in
6. Soil b. Entire plant             c. Parts of plant           d. Seed treatment

 

II State whether the following statements are true or false.                           (5 ´ 1 = 5)

 

6. Mosaic is the symptom for mycoplasmal diseases.
7. Compound interest disease completes more than a cycle during the life period of host.
8. Physiological diseases are caused due to viruses.
9. Bengal famine is caused due to Phytophthora infestans.
10. 20 – 26 ˚C temperature and 90 % humidity favours blast disease.

 

III Complete the following.                                                                            (5 ´ 1 = 5)

 

11. Alternaria solani produces an injurious chemical substance in tomato is ———-.
12. Anthracnose is a symptom for the pathogen ———–.
13. The sexual phase of Pyricularia oryzae is —————- ————.
14. Spermagonium and aecium are seen in the disease ————-.
15. Oxanthiins and benzimidazoles are examples of ———— fungicides.

 

 

 

 

 

IV Answer the following in not more than 50 words each.                           (5 ´ 1 = 5)

 

16. Name the contributions of E.J. Buttler
17. Distinguish alternate and collateral hosts
18. Expand RTBV and RTSV
19. Write note of root knot disease.
20. Give the importance of chitinase and α-amylase inhibitor

 

Part – B

 

Answer any FIVE of the following in not more than 350 words each.      (5 ´ 8 = 40)

 

21. How are inanimates cause disease in crops?
22. Describe the hypertrophy and hyperplasia symptoms in plants
23. Give an account of pathogens, symptoms and control measures of tikka disease.
24. Briefly explain the disease smut of wheat.
25. Write short notes on galls.
26. Describe tungro disease of rice.
27. 27. Write the basic steps in the development of Bt
28. Explain the various causes of epidemics.

 

 

Part – C

 

Answer the following in not more than 1500 words each.                 (2 ´ 20 = 40)

 

1. (a) Write an essay on the various events of pathogenesis.

Or

(b) Explain the pathological life cycle of damping off disease.

 

1. (a) Enumerate the characters of mycoplasma. Add note on the little leaf of brinjal.

Or

(b) Describe the therapeutic measures to control diseases.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.

VE 20

SIXTH SEMESTER – April 2009

PB 6604 – PLANT DISEASES AND MANAGEMENT

 

 

 

Date & Time: 18/04/2009 / 9:00 – 12:00       Dept. No.                                                       Max. : 100 Marks

 

 

PART – A (20 MARKS)

 

1. CHOOSE THE CORRECT ANSWER: (5 x 1 = 5)
2. The most resistant virus, whose thermal deathpoint is 90^oC for 10mts.
3. Tungrovirus, Potatovirus, c. CMV,                      d. TMV
4. It is an ulcer like lesion on fruit, tuber, leaves; as an outgrowth of cortical & epidermal cells.
5. Scab Edema,        c. callus                       d. Tumour
6. Teleutospores are
7. Unicellular bicellular binucleate            c. unicellular bi nucleate          d. bicellular uninucleate
8. The fruit becomes grayish and the skin hardens and c shrivels in
9. Downy mildew on grapes citruscanker             c. little leaf of brinjal
10. Tikka of groundnut
11. The smut fungi belongs to the order.
12. Ustilaginales, Uredinales   c. Peronosporales        d. Mucorales

 

1. COMPLETE THE FOLLOWING : (5 x1 = 5)
2. Parasitic algae in plant is ________________________.
3. _________________ is a substance produced by a pathogen, which inhibits the development of defence reaction in plants.
4. In response to wounding _______________ is the tissue overgrowth as a healing process.
5. Clubroot of cabbage is caused by ______________.
6. ___________________ are Necrotic lesions on the fruits.

 

• STATE WHETHER THE FOLLOWING STATEMENTS ARE TRUE OR FALSE:                                                                                                       (5 x 1 = 5)

11. Viroids are infective nucleic acids, similar to virus, and has a protein covering.
12. Neem cake is very effective in reducing root knot incidence.
13. Colletotriclurm falcatum can be effectively controlled by Bavistin, Topsin, and by Bordeaux mixture.
14. Sulphur is a good fungicide.
15. Plant pathogenic bacteria are mostly grain positive.

 

1. ANSWER THE FOLLOWING IN 50 WORDS EACH: (5 x 1 = 5)
2. Define Inoculam Potential.
3. What are the symptoms of Blight Disease.
4. What is Epidemiology?
5. Describe bacterial gall.
6. Mention any one symptom of viral Disease on plants?

 

PART-B

 

ANSWER ANY 5, EACH NOT MORE THAN 350 WORDS:                           (5 x 8 = 40)

 

21. Explain Epidemics & Endemics.
22. Write down Koch’s Postulates.
23. Explain the inanimate causes of diseases in crops.
24. Explain Hyper Trophy & Hyperplasia, Giving Examples.
25. Write about Tungro disease of Rice.
26. Write notes on Ergot of rye.
27. Write notes on crop protection and Induced resistance.
28. Write about the characters of Mycoplasmas.

PART-C

 

ANSWER THE FOLLOWING IN NOT MORE THAN 1500 WORDS EACH: (2 x 20 = 40)

 

29. Explain the pathological life cycle of wilt of cotton.

OR

Explain the pathological life cycle of Rust of wheat

 

30. Write about the Environmental impacts on Disease development and Epidemics.

OR

Write notes on 1. Plant Quarantine Principles.

2. Disease Forecasting
3. Seed and Soil Treatments.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.

SIXTH SEMESTER – APRIL 2011

PB 6608/PB 6604 – PLANT DISEASES AND MANAGEMENT

 

 

 

Date : 05-04-2011              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A  (20 marks)

 

ANSWER ALL THE QUESTIONS

 

I.CHOOSE THE CORRECT ANSWER :                                                (5 x 1 = 5 marks)

 

1. Which one of the following is not produced by the pathogen ?

[a]  Toxins         [b] Enzymes        [c] Phytoalexins         [d] Growth regulators

 

1. Which one of the symptoms is  produced by viral pathogens?

[a] Chlorosis           [b] Canker        [c] Rot              [d] Wilt

 

1. The causal organism of the club root of cabbage is:

[a] Pernospora parasitica                 [b] Phytophthora infestans

[c] Plasmodiophora brassicae          [d] Fusarium oxysporum

 

1. Tobacco Mosaic Virus can be controlled by

[a] spraying chemicals                  [b] controlling insect vectors

[c] growing resistant varieties       [d] clipping diseased plant parts.

 

1. Which one of the following is an organic mercurial fungicide ?

[a] Agrosan        [b] Bavistin      [c] Captan        [d] Maneb

 

 

1. STATE WHETHER THE FOLLOWING STATEMENTS ARE TRUE OR FALSE :

(5 x 1 = 5 marks)

1. Fungal pathogens penetrate the host by producing appressorium.
2. Horizontal resistance is usually polygenic in inheritance.
3. Damping off is a symptom seen in branch tips.
4. Root knot of potato is caused by nematodes.
5. The ‘safener’ in Bordeaux mixture is copper.

 

III. COMPLETE THE FOLLOWING :                                                                        (5 x 1 = 5 marks)

 

1. Removing the source of inoculum and  preventing the spread of infection is achieved

through —————–.

1. Secondary metabolites of host plant produced in response to pathogen attack are called ————.
2. Red rot of sugarcane is caused by —————— ——————-.
3. Little leaf of brinjal is caused by ———————.
4. Plant quarantine  measures help in preventing —————–.

 

1. ANSWER THE FOLLOWING, EACH WITHIN 50 WORDS:        (5 x 1 = 5 marks)

 

1. Define inoculum potential.
2. What is hypersensitive reaction?
3. What is an alternate host?
4. How are insect galls produced?
5. What is biological control ?

PART – B

 

ANSWER ALL QUESTIONS, EACH WITHIN 500 WORDS, DRAW DIAGRAMS WHEREVER  NECESSARY :                                                                                                           ( 5 x 7 = 35 marks)

 

1. a)  Explain the molecular basis of infection.

(OR)

1. b) What are the various toxins produced by fungal pathogens ?

Point out their role in infection.

 

1. a) What are the induced defence mechanisms seen in host plants ?

(OR)

1. b) Explain the role of environmental factors in the onset of disease.

 

1. a) Give the causal organism, symptoms and control measures for Tikka disease of

groundnut.

(OR)

1. b) Describe the Downy mildew disease of grapes.

 

1. a) Give an account of a disease caused by mycoplasma.

(OR)

1. b) Give an account of angiospermic plant parasite.

 

1. a) Give a concise account of  chemicals used for plant protection.

(OR)

1. b) Write notes on bacterial biopesticide.

 

PART C

 

ANSWER ANY THREE QUESTIONS IN NOT MORE THAN 1200 W0RDS EACH. DRAW DIAGRAMS WHEREVER NECESSARY.                                                       (3 x 15 = 45 marks)

 

1. Elaborate on the concepts in the process of infection.
2. Explain the innate defence mechanisms  encountered in host plants.
3. Discuss the causal organism, symptom and control measures of Rust of wheat.
4. Give a brief account of the diseases of paddy crop –fungal, bacterial and viral.
5. Highlight the role of engineered resistance in plant disease control.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

U.G. DEGREE EXAMINATION – PLANT BIOLOGY & BIOTECHNOLOGY

SIXTH SEMESTER – APRIL 2012

PB 6608/PB 6604 – PLANT DISEASES AND MANAGEMENT

 

 

 

Date : 16-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART – A     

 

Answer the following each in about 50 words:                                                               (10 x 2 = 20)

 

1. Define infection.
2. What is meant by secondary inoculums?
3. What are phytoalexins?
4. What is hypersensitivity.                                             
5. Write about the causal organism for Club root of cabbage.
6. What is Acervulus?
7. Name the pathogen and control measure for Blight of rice.
8. Write notes on galls.
9. Give the composition of Bordeaux mixture.
10. What is meant by Field sanitation?

 

PART – B

 

Answer the following each answer not exceeding 500 words:

Draw diagrams wherever necessary:                                                                               (5 x 7 = 35)

 

 

11. a. Discuss the role of growth regulators in the development of plant disease.

(or)

1. Explain Koch’s postulates.

 

12. a. Discuss the role of light and temperature in disease development.

(or)

1. Write notes on:

(i)   Natural openings

(ii)  Deposition of gums

 

13. a. Write an account on Tikka disease of groundnut.

(or)

1. Describe briefly about the disease caused by Puccinia graminis tritici.

 

14. a. Briefly describe any one viral disease you have studied.

(or)

1. Write short notes on Cuscuta.

 

15. a. Give an account of quarantine regulations.

(or)

1. Explain soil and seed treatment for eradication of plant diseases.

 

PART – C     

 

Answer any three of the following each answer not exceeding 1200 words.

Draw diagrams wherever necessary.                                                                                (3 x 15 = 45)

 

 

16. Describe the morphological and anatomical changes in the host plant due to pathogenesis.
17. Give a detailed account on Induced histological defence mechanism.
18. Discuss in detail about Blast of rice.
19. Explain the pathogen, symptoms and control measures of Citrus canker.
20. Write an essay on the biological control of plant diseases.

 

 

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