LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.
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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)
- CHOOSE THE CORRECT ANSWER: (5 x 1 = 5)
- The most resistant virus, whose thermal deathpoint is 90oC for 10mts.
- Tungrovirus, Potatovirus, c. CMV, d. TMV
- It is an ulcer like lesion on fruit, tuber, leaves; as an outgrowth of cortical & epidermal cells.
- Scab Edema, c. callus d. Tumour
- Teleutospores are
- Unicellular bicellular binucleate c. unicellular bi nucleate d. bicellular uninucleate
- The fruit becomes grayish and the skin hardens and c shrivels in
- Downy mildew on grapes citruscanker c. little leaf of brinjal
- Tikka of groundnut
- The smut fungi belongs to the order.
- Ustilaginales, Uredinales c. Peronosporales d. Mucorales
- COMPLETE THE FOLLOWING : (5 x1 = 5)
- Parasitic algae in plant is ________________________.
- _________________ is a substance produced by a pathogen, which inhibits the development of defence reaction in plants.
- In response to wounding _______________ is the tissue overgrowth as a healing process.
- Clubroot of cabbage is caused by ______________.
- ___________________ are Necrotic lesions on the fruits.
- STATE WHETHER THE FOLLOWING STATEMENTS ARE TRUE OR FALSE: (5 x 1 = 5)
- Viroids are infective nucleic acids, similar to virus, and has a protein covering.
- Neem cake is very effective in reducing root knot incidence.
- Colletotriclurm falcatum can be effectively controlled by Bavistin, Topsin, and by Bordeaux mixture.
- Sulphur is a good fungicide.
- Plant pathogenic bacteria are mostly grain positive.
- ANSWER THE FOLLOWING IN 50 WORDS EACH: (5 x 1 = 5)
- Define Inoculam Potential.
- What are the symptoms of Blight Disease.
- What is Epidemiology?
- Describe bacterial gall.
- Mention any one symptom of viral Disease on plants?
PART-B
ANSWER ANY 5, EACH NOT MORE THAN 350 WORDS: (5 x 8 = 40)
- Explain Epidemics & Endemics.
- Write down Koch’s Postulates.
- Explain the inanimate causes of diseases in crops.
- Explain Hyper Trophy & Hyperplasia, Giving Examples.
- Write about Tungro disease of Rice.
- Write notes on Ergot of rye.
- Write notes on crop protection and Induced resistance.
- Write about the characters of Mycoplasmas.
PART-C
ANSWER THE FOLLOWING IN NOT MORE THAN 1500 WORDS EACH: (2 x 20 = 40)
- Explain the pathological life cycle of wilt of cotton.
OR
Explain the pathological life cycle of Rust of wheat
- Write about the Environmental impacts on Disease development and Epidemics.
OR
Write notes on 1. Plant Quarantine Principles.
- Disease Forecasting
- Seed and Soil Treatments.
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