Crop border and mineral oil sprays used in combination as physical control methods of the aphid-transmitted potato virus Y in potato

BACKGROUND: The objectives of this work were to determine if the control of potato virus Y (PVY, genus Potyvirus, family Potyviridae) in seed potato could be improved by combining border crops and mineral oil sprays, and if the border crop acts as a barrier or a virus sink. RESULTS: Field tests over 3 years confirmed that mineral oils alone are an effective barrier to PVY, and showed that borders alone act as a PVY sink. Combining the familiar mineral oil and the more recent crop border methods was almost twice as effective in reducing PVY incidence as either one used alone. The combination provided consistently high PVY control compared with the variable and often lower level of control by either method alone. The contribution of the oil to PVY reduction was similar whether it was applied to the border, the center seed plot, or both. Oil application to the border alone should not affect efficacy and would help keep control costs down. CONCLUSION: Combining border and oil provided the best reduction in PVY incidence 3 years out of 3, providing producers with a tool to reduce year-to-year variation in the effectiveness of crop borders or oil sprays used separately. (C) Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada. Published by John Wiley and Sons, Ltd.