INCIDENCE OF APHID BORNE VIRUSES AND THEIR VECTOR DYNAMICS INFECTING POTATO CROP IN DIFFERENT DISTRICTS OF AZAD JAMMU AND KASHMIR, PAKISTAN

Abstract

Potato crop production is hampered by several fungal, viral, and bacterial diseases. Among the viral Potato leaf roll virus (PLRV), Potato virus Y (PVY), Potato-mop-top-virus (PMTV), Potato virus S (PVS) and Potato virus X (PVX) are the most important. Potato growing fields were surveyed during 2016 and 2017 to determine the incidence of two aphid-borne viruses, PVY and PLRV and to explore the dynamics of potato aphids in four potato-producing district of Azad Jammu & Kashmir (AJK), Pakistan. During survey 930 leaf samples were collected from various locations of Bagh, Sudhnoti, Poonch and Neelum. Parameters determined included aphid population, symptomology, DAC-ELISA based virus incidence, rate of co-infection and disease severity. Overall relative disease incidence of PLRV and PVY was 48.71% and 53.23% respectively. The highest average aphid’s population per field was 390.27 in Sudhnoti due to the low altitude of the surveyed locations. Three aphid species Myzuspersicae Myzusornatusand, Macrosiphum euphorbiaewere identified in AJK potato fields. Themaximum co-infection was recorded from Poonch. It was found that aphid populations decreased with the increase of altitude. The incidence of PLRV and PVY were high where aphid population was high. Therefore, it is necessary to promote awareness among the farmers on virus and aphid symptoms identification and to recommend use of healthy, uncontaminated certified potato seed.