D3415: Do cover crops and reduced tillage suppress aphids and potato virus Y in potato?

Reliance on conventional tillage and insecticide-based pest management practices in Pacific Northwest potato production threatens economic and environmental sustainability. In Idaho seed potato systems, aphid vectors of Potato virus Y (PVY)—one of the most economically damaging pathogens—are the primary targets of insecticide applications. Although cover crops and reduced tillage are known to improve soil health and insect pest management in other systems, their influence on aphid populations, natural enemies, and virus risk in potato remains poorly understood. This study evaluated how fall-sown cover crop mixtures and reduced tillage affected aphid settling activity, aphid densities, and PVY incidence in potato plots in Idaho. Treatments included (1) fall-sown cover crops, (2) reduced tillage, and (3) a check featuring conventional tillage and no cover crop. Potato-colonizing and non-colonizing aphid species were monitored using yellow bucket traps, green tile pan traps, and beat sampling. Natural enemies and other pestiferous arthropods were sampled via vacuum sampling. PVY infection was evaluated in-season and post-harvest using ELISA. We hypothesize that cover crops and reduced tillage will reduce aphid settling and PVY transmission by altering soil properties and enhancing early-season natural enemy presence. These practices may be most effective early in the season when potatoes are more susceptible to damage. By linking conservation tillage and cover crop practices to insect ecology and virus suppression, this study will provide insights into how agroecosystem management may contribute to sustainable potato production and enhanced IPM strategies in the Pacific Northwest.