Q.1. Tick the correct answer?

1) Damping –off of seedlings is caused by

(a) Pythium spp. (b) Phytophthora spp. (c) Rhizoctonia solani (d) All of these

2) Damping-off of seedlings is favoured by

(a) High soil moisture and low soil temperature
(b) Moderate soil moisture and moderate soil temperature
(c) Low soil moisture and high soil temperature
(d) High soil moisture and high soil temperature

3) Bacterial spot in nursery is caused by

a) Xanthomonas campestris pv. vesicatoria b) Xanthomonas campestris
c) Xanthomonas campestris pv. campestris d) None

4.) Root knot in nursery is caused by:

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

Answers: 1.d. 2. d 3. a 4. d

Q. 2. Fill in the blanks

1.Species of Pythium attacks the seedlings in ___________________________ stage.
2. Symptoms of damping off appear in ___________________________ and __________________ phases.
3. Patchy appearance of seedlings in nursery beds is the characteristic feature of ________________ phase.
4. Invariably nurseries of tomato, raised in untreated soils are infested with nematodes like ___________________________
5. Virus diseases are transmitted through their insect vectors like _________________ and ________________.

Answers: 1. Juvenile 2. Pre- and post-emergence 3. Pre-emergence 4. Meloidogyne spp.5. Aphids, white fly

Subjective type Questions

Q. No. 3. Describe in detail the symptoms, causal agent disease cycle and management of
damping-off of seedlings.

Q.No.4. Write a note on the management of viral and bacterial diseases of nursery.

Last modified: Thursday, 1 March 2012, 9:31 AM