Potato leaf roll

A brief description about the viral disease potato leaf roll......

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

2. POTATO LEAF ROLL ©ahdb.org.uk

3. Scientific Name Potato leaf roll virus Other Scientific Names Potato leaf roll luteo virus Potato phloem necrosis virus

4. SYSTEMIC POSITION Domain: Virus (RNA)             Family: Luteoviridae                Genus: Polerovirus                   Species: Potato leafroll virus

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.

8. Upward Curling of the leaf ©agric.wa.gov.au

9. Stunted Growth ©agric.wa.gov.au

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 .

15. REFERENCES https://www.agric.wa.gov.au/potato-leafroll-virus-potato-crops R. S. Singh, Plant Diseases, Oxford& IBH Publishing. Co. pvt . Ltd- 9th edition, New Delhi , Pg No: 528-530 Thinda . T. S, Diseases of Fruits and vegetables and their management, Kalyani publishers, 2001.