1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
POTATO LEAF ROLL
Course teacher: Student:
Dr. Parthasarathy. S Miss. Sharmitha.S
Asst. Professor (Plant Pathology) 2015021116
5. HISTORY
• Potato leaf roll virus (PLRV) causes a disease
of potatoes worldwide and occurs in Western
Australia.
• PLRV was first described by Quanjer et al. in
1916.
• It can be responsible for individual plant yield
losses of over 50%.
6. SYMPTOMS
• A slight rolling and red/orange tinge can occur
in the upper leaves.
• The bottom leaves may roll and the leaves are
dry and brittle and have a papery feel.
7. • The plant show a slight yellowing and
upturning of the upper leaves.
• Plant growth can be marginally reduced or
extremely stunted.
10. Mode of spread
• PLRV is transmitted by aphids in a persistent manner-
once an aphid acquires the virus it is infective for life.
• The virus is picked up by colonising aphids during
prolonged feeding on an infected plant. The peach
potato aphid (Myzus persicae) is regarded as the most
efficient vector.
11. Favourable Condition
• Aphids might be playing a key role in
transmission and spread of PLRV during the
months of October and February because of
warm climatic conditions (18-24ºC).
12. Management
Preventive measures
• Use seed tubers from healthy plants or use certified
seeds.
• Use resistant varieties.
Monitor the field, pick and destroy diseased plants.
Destroy weeds and volunteer plants that can host the
virus and feed the aphids.
13. Biological control
Direct treatment of the virus is not possible,
but reducing aphid population by means of
predators or parasitoids.
Parasitic wasps could also be used.
14. Chemical control
• Chemical treatment of viral diseases is not
possible.
• Apply insecticides in the early phases of crop
growth .
