Diseases of Vegetable, Ornamental and Spice Crops

QUESTIONS

Q. No.1. Tick the correct answer
1. Phomopsis blight is severe in:

a) High RH and high temperature b) Low RH and low temperature
c) Low RH and high temperature d) None

2. Seed borne inoculums of Phomopsis blight can be reduced by:

a) Seed treatment with carbendazim b) Seed treatment with captan
c) Seed treatment with mancozeb d) Seed treatment with copper oxychloride

3. Perfect stage of Phomopsis vexans is:

a) Diplocarpon rosae b) Diaporthe vexans

c) Phoma spp. d) Phyllosticta spp.

4. Phomopsis vexans overwinters in:

a) Seed b) Plant debris c) Seed and plant debris d) None

5. Sclerotinia sclerotiorum overwinters in the form of:

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

6. Sclerotia of Sclerotinia sclerotiorum germinate by forming:

a) Apothecia b) Conidia c) Macroconidia d) None

7. Optimum temperature for Sclerotinia sclerotiorum infection is:

a) 0-10o C b) 10-15o C c) 15-20o C d) 25-30o C

8. Cercospora leaf spots are severe during:

a) Warm days and cool nights b) Cool days and cool nights
c) Warm days and warm nights d) None

9. Local transmission of Cercospora spp. is helped by:

a) Moist wind and irrigation water b) Dry wind and irrigation water
c) Moist wind and rainfed conditions d) None

10. Incidence of bacterial wilt increase with:

a) Decrease in altitude b) Increase in altitude
c) On intermediate elevations d) None

11. Little leaf disease is more serious in:

a) Southeast Asian countries b) South African countries
c) Southwest Asian countries d) None

12. Little leaf disease is caused by:

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

13. Little leaf symptoms are characterized by:

a) Reduction in leaf size having shortened petioles b) Reduction in branches
c) Reduction in size of stems d) None

14. Little leaf is transmitted by:

a) Leaf hopper b) Aphids c) Whitefly d) Thrips

15. Little leaf Phytoplasma perennates in

a) Soil b) Weed hosts c) Seed d) None

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

Q.No. 2. Fill in the blanks

1. Symptoms of Phomopsis blight in nursery appear as -----------------------------.
2. Phomopsis blight on fruits manifests as -----------------------------------.
3. The perfect stage of Phomopsis vexans is -------------------------------.
4. Phomopsis vexans produces --------------------- and ----------------------- spores.
5. Beta form of conidia, the stylospores is -----------------------, ---------------------, --------------------------- and -----------------------.
6. Asci of Diaporthe vexans contains---------------------------- number of ascospores.
7. Phomopsis vexans is --------------------------- borne and also survives in---------------------------.
8. Little leaf of brinjal is caused by ----------------------.
9. Little leaf of brinjal is transmitted by -----------------.
10. Alpha spores of Phomposis vexans are converted into beta spores at --------- oC.
11. Leaf spots of brinjal are caused by ---------------- and --------------------.
12. Bacterial wilt of brinjal is caused by ----------------------.
ANSWERS : 1) damping off 2) pale sunken spots 3) Diaporthe vexans 4) alpha and beta spores 5) filiform, curved, hyaline and septate 6) eight 7) seed borne, plant debris 8) phytoplasma 9) leafhopper 10) 10- 16 11) Cercospora melongenae, Cercospora egenulae 12) Ralstonia solanacearum

Subjective type

1. Write down the causal organisms of following diseases:

a. Little leaf of brinjal
b. Phomopsis blight of brinjal

2. Write down the symptoms and epidemiology of following:

a. Phomopsis blight of brinjal
b. Bacterial wilt of brinjal

3. Write down the management strategies of following diseases:

a. Cercospora leaf spots of brinjal
b. Phomopsis blight of brinjal