Diseases of Vegetable, Ornamental and Spice Crops

QUESTIONS

Q. No. 1. Fill in the blanks:

i. The powdery mildew of rose is caused by ----------------------------------------.
ii. A temperature of ---------and relative humidity ranging between ------------- is quite effective for the spread of the powdery mildew of rose .
iii. Black spot of rose is also known as--------, ---------,-------------- , -------------------and --------------- and-------------------.
iv. The apothecia Diplocarpon rosae are ---------------- to ---------------- shaped, subcuticular, radiate and are ---------- µm in dia.
v. The Rapid spread of black spot of rose at optimum temperature ------------and more than ----------relative humidity is favourable.
vi. The grey mold of rose is caused by ---------------.
vii. The post harvest development of grey mould in cut flowers can be suppressed when flower buds are sprayed with 1 mM solution of -----------------.
viii. Rose rust is caused by ----------------- and fungus overwinters either in the form of -------------or as---------- in the infected stems.
ix. Hyperparasites such as ----------------, ----------------and -------------can be used as biocontrol agents to control rust.

Answer key

i. Sphaerotheca pannosa var. rosae ii. 21oC, 97-99% iii. leaf blotch, leaf spot, blotch, rose actinonema, rose leaf asteroma, star sooty mould iv. globose, disc, 100-300 v. 24oC, 85% vi. Botrytis cinerea, vii. giberellic acid viii. Phragmedium , teliospores, mycelium ix. Darluca filvum, Tuberculina vinosa, Verticillium lecani

Q2. Choose correct answers from the following questions:
1. Aecial fruiting bodies are raised, orange-coloured and produced in disease like

1. Leaf blight 2. Rust 3. Leaf spot

2. Cladosporium and Tellitiopsis spp. are well known hyperparasites of which disease

1. Powdery mildew 2. Rust 3. Shooty mould

3. The causal organism of downy mildew of rose is

1.Sphaceloma rosarum 2. Chlaropsis thielavioli 3. Peronospora sparsa

4. Diplodia sp. causes die –back in which crop

1. Geranium 2. Crossandra 3. Rose

5. Photosynthetic activity of leaves is reduced in which disease

1. Powdery mildew 2. Mosaic 3. Grey mould

6. Mature twigs of the rose is more attacked than the young twigs in which disease

1. Rust 2. Crown gall 3. Die-back

7. Yellowing and heavy defoliation is the part of which disease

1. Black spot 2.Rust 3. Downy mildew

Answers 1. 2, 2.1, 3. 3, 4. 3, 5. 1, 6. 3, 7. 1

Q3. Write true or false against the following statements

1. Cephalosproium sp. and Tilletiopsis sp. are well known hyperparasites of grey mould disease of rose.
2. Triforine and Fenarimol are EBI fungicides targeted to control Downy mildew diseases.
3. Jawahar and Pusa Sonia varieties of rose are resistant to black spot disease.
4. Rust of rose can be checked by use of Darluca filvum and Verticillium lecani as hyperparasites.
5. Acecial and urediospores are produced in smut diseases.
6. Black spot fungus of rose produces apothecia and acervuli as their fruiting structure in perfect and imperfect states.
7. Karathane is effective chemical to powdery mildew infection.
8. Rose rust is checked by hyperparasites like Verticillium lecani and Darluca filvum.
9. Rovaral and Benomyl are effective against Downy mildew of rose.

Answers: 1. F, 2. F 3. T, 4. T 5. F 6. T 7. T 8. T 9. F

Q. 3. Enlist important fungal diseases of rose alongwith their causal agents

Q.4. Describe rust disease in detail by giving symptomatology, epidemiology and management.

Q.5. Discuss black spot of rose in detail including its control.

Q.6. Write short note on the following diseases

1. Crown gall of rose
2. Powdery mildew of rose

 
Q.7. Write down the characteristic symptoms of the following diseases

1. Black spot of rose

 
Q. 8. Mention control measures of the following diseases

1. Powdery mildew of rose
2. Grey mould of rose