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

QUESTIONS

Q.No. I Tick the correct answer
1.Fusarium wilt is more serious during

a) Winter b) Autumn c) Summer d) None

2. Vascular bundles of Fusarium wilt affected plants appear as:

a) Brown b) Yellow c) Brown streaks d) Dark streaks

3. Macro conidia of Fusarium oxysporum f. sp. vasinfectum are mostly:

a)1 Septate b) 2 Septate c) 3 Septate d) 5 Septate

4. Fusarium oxysporum f. sp. vasinfectum overwinters in soil as:

a) Oospore b) Conidia c) Chlamydospores d) None

5. Optimum temperature for the growth of Fusarium oxysporum f. sp. vasinfectum:

a) 20o C b) 25o C c) 30o C d) 15o C

6. Cultivar Pusa Makhmali is resistant to :

a) Yellow vein mosaic b) Powdery mildew c) Cercospora leaf spot d) Fusarium wilt

7. Leaf spot of okra is generally caused by:

a) Alternaria spp. b) Cercospora spp. c) Phyllosticta spp. d) Phoma spp.

8. Dark olivaceous patches of mould on the lower surface of okra is due to infection of:

a) Cercospora hibiscina b) Cercospora malayensis c) Cercospora abelmoschi d) None

9. For the development of Cercospora leaf spot, Cercospora requires:

a) Moderate temperature and high humidity b) High temperature and high humidity
c) Low temperature and high humidity d) High temperature and low humidity

10. Each cleistothecium of Erysiphe cichoracearum contains:

a) 2-3 asci b) 10-15 asci c) 8 to 18 asci d) 20-25 asci

11. For growth and sporulation, Erysiphe cichoracearum requires:

a) Wet conditions b) Dry conditions c) Extremely wet conditions d) None

12. Yellow vein mosaic of okra is transmitted by:

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

13.Powdery mildew of okra can be effectively managed by sprays of :

a) Bordeaux mixture b) Captan c) Mancozeb d) Hexaconazole

14. In yellow vein mosaic infected leaves, chlorophyll is :

a) Increased b) Decreased c) Normal d) None

15. Occurrence of yellow vein mosaic is delayed in:

a) Black mulch b) White mulch c) Yellow mulch d) Red mulch

Answers

1. c 2. d 3. c 4. c 5 b 6 d 7. b 8 a 9 a 10. c 11. b 12 a 13 d 14 b 15 c

Q. No. 2. Fill in the blanks

1. Fusarium wilt is more serious in the crop planted during -------------------- months.
2. Vascular bundles in case of Fusarium wilt appear as----------------------.
3. Macroconidia of Fusarium oxysporum f.sp. vasinfectum are formed on ---------------------- and ------------------------.
4. Chlamydospores of Fusarium oxysporum f.sp. vasinfectum are both ---------------- and --------
5. Fusarium oxysporum f.sp. vasinfectum overwinters in the form of ----------------- and -----------
6. Cercospora species overwinter in the infected------------------- and also on the -------------------- species of Abelmoschus.
7. The genome of yellow vein mosaic virus is---------------------- DNA.
8. In nature, yellow vein mosaic is transmitted by ----------------------------.
9. -------------------- weather with --------------- or ---------- rainfall is conducive for yellow vein mosaic development.
10. Cultivars like ---------------------, --------------------------- and ------------------------- are resistant to yellow vein mosaic.
11. Fusarium wilt of okra is caused by --------------------.
12. Powdery mildew of okra is caused by ---------------------.
13. Yellow Vein Mosaic Virus (YVMV) of okra belongs to the --------- group.
14. In powdery mildew of okra, the number of ascospores per ascus is usually ------------- and rarely ----------------------.
15. Okra powdery mildew pathogen requires ----------------- % RH for the development of the disease and ------------ conditions for the growth and sporulation of the fungus.

Answers
1. Summer 2. Dark streak 3. Sporodochia and pionnotes 4. Intercalary and terminal, 5. Chlamydospores, infected seeds 6. Plant debris, wild 7. Single stranded 8. White fly 9. Dry hot, little, no 10. Punjab Padmini, Punjab-8 and Prabhani Kranti.11) Fusarium oxysporum f.sp. vasinfectum 12) Erysiphe cichoracearum 13) bigeminivirus group 14)2, 3 15) 60-80 per cent, dry.

Subjective type questions:

1. Write down the management strategies of following diseases:

a. Fusarium wilt of okra
b. Downy mildew of okra
c. Cercospora leaf spot of okra

2. Write a short note on the symptoms and epidemiology of following:

a. Yellow vein mosaic
b. Powdery mildew of okra

3. Write down the symptoms and management practices for Fusarium wilt of okra.