Epidemiological approaches to control aphid-borne Potato virus diseases in Meghalaya, India

A weekly aphid survey was conducted in Meghalaya under autumn potato crop in order to know the build-up trends and early arrival of Green Peach Aphid (Myzus persicae) which was the most important vector for virus spread through simple aphid-leaf count and catches of yellow water pan and yellow sticky traps. Alate (winged) morphs were first appeared in sticky traps as well as in the standing crop (first week of September) immediately after the crop emergence at higher altitudes while at lower altitudes it was recorded in the last week of September during all the four consecutive years at almost all the surveyed sites. The result revealed that the aphid population build-up was due to combined effect of abiotic factors like temperature (maximum & minimum), relative humidity, rain fall and total sun shine hours. The abiotic factors were quite different due to the fact that the climatic condition in surveyed period varied distinctly. The aphid population remained above the critical level throughout the crop season at almost all the locations except CPRS because integrated approach to controlling these viruses by minimising the inocula sources and using the systemic insecticides at regular intervals were practiced. Virus incidence was recorded based on visual symptoms in the farmers’ fields and principal potato viruses viz. PVX, PVS, PVA, PVY, PVM and PLRV were tested with the samples collected randomly by using ELISA revealed the presence of viruses either transmitted through contact or by aphid vectors.