Diseases of Vegetable, Ornamental and Spice Crops

QUESTIONS

Q.No. 1. Tick the correct answer
1. Powdery mildew of pea is more serious in:

a) Dry weather b) Wet weather c) Cold weather d) Rainy weather

2. Symptom of pea powdery mildew appear on which surface of leaf

a) Lower b) Upper c) Both upper and lower d) None

3. Erysiphe pisi is:

a) Endoparasitic b) Ectoparasitic c) Intercellular d) Intracellular

4. Each ascus of Erysiphe pisi contains:

a) 1-2 ascospores b) 2-4 ascospores c) 3-5 ascospores d) 2-8 ascospores

5. Pea powdery mildew can be effectively managed by sprays of:

a) Wettable sulphur b) Copper oxychloride c) Bordeaux mixture d) Captan

6. Fusarium oxysporum f.sp. pisi Race 1 causes:

a) Near wilt b) True wilt c) False wilt d) Pseudo wilt

7. Near wilt of pea is more serious in:

a) Dry soil b) Wet soil c) Neutral soil d) Moist soil

8. In nature pea rust is:

a) Heteroecious b) Intermediate c) Autoecious d) Soil borne

9. White rot fungus overwinters in the form of:

a) Oospore b) Cleistothecia c) Sclerotia d) Chlamydospore

10. For infection of Ascochyta spp., atmospheric RH should be :

a) > 70% b) >80% c) >90% d) <80%

11. Pseudomonas syringae pv. pisi is:

a) Gram –tive b) Gram +tive c) Gram –tive motile rods

d) Gram-tive motile rods with one or more polar flagella

12. Bacterial blight pathogen overwinters in:

a) Soil b) Seed c) Plant debris d) Straw

13. Infection of Pseudomonas syringae pv. pisi takes place through:

a) Hydathodes b) Stomata c) Lenticels d) Petioles

14. Bacterial blight is favoured by weather:

a) Cool and moist b) Warm and moist c) Warm and dry d) Cool and dry

15. Pea seed borne mosaic virus belongs to:

a) Geminivirus b) Caulivirus c) Potyvirus d) Begamovirus

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

Q.No.2. Fill in the blanks

1. Symptoms of powdery mildew appear on -------------------, ----------------------- ----------------------, and -----------------------.
2. Each cleistothecium of Erysiphe pisi contains --------------------- asci.
3. Conidial of Erysiphe pisi are dispersed ------------------- and cause ---------------- secondary spread of the disease.
4. A fairly ------------------- soil and heavy application of ------------------- fertilizers increase the powdery mildew severity.
5. Early sown crops ------------------------ the powdery mildew infection.
6. Fusarium wilt is of two types i.e. ------------------ and -------------------.
7. In true wilt, -------------------- to ---------------------- discolouration of vascular system is
8. In nature, Pea rust is an --------------------- rust.
9. The causal organism of powdery mildew of pea is -------------.
10. ------------------ is the resting structure of pea powdery mildew pathogen.
11. Rust of pea is caused by ---------------------.
12. Overwintering structure for the white rot of pea is -----------------.
13. ------------- and -------------- weather favours the bacterial blight.
14. Pea Seed Borne Mosaic Virus belongs to ----------------- group and is transmitted by -------------, ------------------ or ---------------- vectors.

Answers

1. Leaves, tendrils, stems, pods 2. 2-8 3. Passively, secondary 4. Dry, nitrogenous 5. Escape 6. True, Near 7. Yellow, orange brown 8. Autoecious 9. Erysiphe pisi 10. Cleistothecia 11. Uromyces viciae fabae 12. Sclerotia 13. Cool, moist 14. poty virus (PSbMV), Acyrthosiphon pisum, Aphis craccivora or A. fabae.

Q.No. 3 Subjective type questions:

1. Write down the causal organism and characteristic symptoms of following diseases:

a. Fusarium wilt of pea
b. Ascochyta Blight
c. Pea rust
d. Bacterial blight of pea

2. Write down the management practices for the following diseases:

a. Powdery mildew of pea
b. Pea rust
c. Bacterial blight of pea

3. Write down the disease cycle and epidemiology of following diseases:

a. Powdery mildew of pea
b. Ascochyta Blight