Diseases of Vegetable, Ornamental and Spice Crops (2+1)

QUESTIONS

Q.No. 1. Tick the correct answer
1. Late blight of potato was first recorded in which area:

a) Andes Mountains of North America b) Andes Mountains of South America
c) Andes Mountains of East America d) Andes Mountains of West America

2. Irish Famine occurred in which year:

a) 1842 b) 1843 c) 1844 d) 1845-46.

3. Whitish downy growth of Phytophthora infestans appears on which surface of the leaf:

a) Upper b) Lower c) Both d) On all green parts of the plant

4. Late blight infected tubers initially looks like

a) Firm and dry b)Soft and dry c) Soft and loose d) Firm and loose

5. For sexual reproduction Phytophthora infestans is:

a) Homothallic b) Heterothallic c) Autoecious d) Heteroecious

6. In India which mating type of Phytophthora infestans commonly occur:

a) A1 and A2 b) A2 c) A3 d) A4

7. Phytophthora infestans perpetuate as dormant mycelium in tubers

a) Cold store b) Field c) Plant debris d) Soil

8. Late blight also infect:

a) Bell pepper b) Chili c) Tomato d) Brinjal

9. Dutch rules were developed for the prediction of:

a) Early blight b) Late blight c) Leaf blight and fruit rot d) Alternaria leaf spot

10. Perfect stage of Alternaria solani is:

a) Diaporthe vexans b) Glomerella cingulata c) Unknown d) Diplocarpon rosae

11. Early blight can be limited by sprays of:

a) Carbendazim b) Benomyl c) Mancozeb d) Thiophanate methyl

12. Black scurf of potato affects:

a) Quality b) Shine c) Shape d) Colour

13. Black scurf appears in how many phases:

a) Four b) Three c) Five d) Two

14. Most prominent symptom of black scurf is the presence of:

a) Brown crust b) White crust c) Black crust d) Violet crust

15. Black scurf is caused by:

a) Macrophomina phaseolina b) Rhizoctonia solani c) Sclerotium rolfsii d) Sclerotinia sclerotiorum

16. Most prominent symptoms of black scurf is the presence of black crust on tubers due to formation of:

a) Conidia b) Acervulus c) Sclerotia d) Ascospores

17. In black scurf sclerotia produced are:

a) Internally b) Superficially c) Deep into the tissue d) Inside the tissue

18. The perfect stage of Rhizoctonia solani is:

a) Glomerella cingulata b) Diaporthe vexans c) Pseudoperonospora cubensis
d) Thanatephorus cucumeris

19. Rhizoctonia solani perpetuate in soil in the form of:

a) Perithecia b) Cleistothecia c) Chlamydospores d) Sclerotia

20. Which phase of black scurf is not common in North India:

a) Stem canker b) Black scurf c) White scurf d) Stem canker and blight

21. In black scurf phase sclerotia formation is favoured at temperature:

a) 20o C b) 25^o C c) 28^o C d) 30^o C

22. Potato wart is most serious in which region of the world:

a) Temperate b) Tropical c) Subtropical d) Sub temperate

23. In India, domestic quarantine is operative against which disease:

a) Black scurf of potato b) Potato Wart
c) Potato Hairy root d) Potato Root knot

24. Potato wart overwinters in the form of:

a) Oospore b) Resting sporangia c) Chlamydospore d) Conidia

25. Common scab is caused by:

a) Fungi b) Bacteria c) Virus d) Phytoplasma

26. Streptomyces scabies is:

a) Gram-tive b) Gram + tive c) Gram – tive and aerobic d) Gram +tive and aerobic

27. Streptomyces scabies is more active in pH range of:

a) 0-2 b) 9-10 c) 5.2-8.0 d) 3-5

28. Most of the viral diseases in potato are transmitted by:

a) Leaf hopper b) Aphid c) White fly d) Nematodes

29. Aphid population can be kept under check by sprays of:

a) Malathion b) Thiodan c) Metasystox d) Metacid

30. Optimum temperature for common scab infection is:

a) 10o C b) 15o C c) 20o C d) 25o C

Answers

1 b, 2 d 3 b 4 a 5 b 6 a 7 a 8 c 9 b 10 c 11 c 12 a 13 d 14 c 15 b 16 c 17 b 18 d 19 d 20 d 21 c 22 a 23 b 24 b 25 b 26 d 27 c 28 b 29 c 30 c

Q. NO. 2 Fill in the blanks

1. In India, occurrence of late blight was first recorded from---------------- in between ---------- and --------------------.
2. In late blight infect field, tubers get infection by---------------- sporangia from foliage.
3. Sporangia of Phytophthora infestans are----------------------- shaped and -------------------- papillate.
4. For sexual reproduction, Phytophthora infestans requires ------------------ mating types.
5. Anthredia of Phytophthora infestans is ------------------- while oogonia are--------------------.
6. Late blight pathogen overwinters as-------------------- in the infected tubers.
7. Late blight pathogen can overwinter as dormant mycelium in infected tubers in the field at temperature --------------------^oC.
8. Initial ---------------------- temperature help in assuming the high late blight severity in the crop.
9. Development of forecasting method is primarily based on record of ---------------- and ------------------ or -------------------------.
10. Early blight is more severe when the plants are predisposed by--------------------, -------------------- or other types of--------------------.
11. Cultivar ------------------- provides good resistance to early blight of potato.
12. Black scurf causes qualitative damage as it decreases the ------------- and ------------------- of the tubers.
13. Black scurf on tubers is more common in crops grown in --------------- to--------------- and moderately ----------------- soils.
14. --------------- to------------------ years rotation with cereals, Brassicas and legumes help in the management of black scurf.
15. In north India, more common phase of stem canker and black scurf is --------------------- where the sclerotia formation is favoured at-------^o C.
16. Planting of -------------- and ------------tubers is helpful in reducing black scurf incidence.
17. In India, Potato wart was first reported from------------------ in the year -----------.
18. CPRI potato varieties like ---------------------,--------------------------- and------------------- are resistant to wart .
19. --------------------- tubers play major role in perpetuation of common scab.
20. Common scab pathogen is more active in --------------- and is suppressed by -------------------.
21. Potato leaf roll is more serious in------------------- climate.
22. ------------------------- manuring and cultivation of certain --------------- before planting potato are important.
23. Streptomyces scabies is ---------------- and ----------------.

Answers:

1 Nilgiri Hills, 1870, 1880 2 Rain washed 3 Lemon, distinctly 4 Two 5 Amphigynous, spherical 6 Dormant mycelium 7 <30o C 8 Low 9 Temperature, rainfall, relative humidity 10 Injury, poor nutrition, stress 11 Kufri Sindhuri 12 Quality, market value 13 Sandy, sandy loam, wet 14 Two to four 15. Black scurf, 28o C, 16 Healthy, disease free, 17 Darjeeling, 1953, 18 Kufri Jyoti, Kufri Sherpa, Kufri Muthu 19. Infected 20 Dry soils, watering 21 Warm 22 Green, Legumes 23 Gram + tive, aerobic.