The Grower's Toolbox Protecting Potatoes From Nematodes By Inga Zasada, Nematologist and PAPAS Project Co-Director
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ou can’t see them, but they’re there: tiny, persistent pests that threaten one of America’s most valuable crops. Potato nematodes don’t just damage roots. They can devastate yields, restrict market access and persist in the soil for years. Unchecked, nematode infestations can lead to significant crop loss – sometimes reducing yields by up to 60% – and economic impacts through trade and planting restrictions and affected tubers not meeting market or export standards. Managing plant-parasitic nematodes is essential for maintaining healthy potato crops, minimizing yield losses and ensuring high-quality tubers. However, the ongoing difficulty and expense of managing nematodes in potato production is a challenge for the industry. For decades, growers have fought these invisible enemies with fumigation, crop rotation and strict sanitation
Oregon State University graduate student Gabby Studebaker conducts field research on the impact of root-knot nematode levels on potato quality and yield.
28 Potato Country • December 2025
measures. While these practices remain essential, other management options need to be considered.
Nematode-Resistant Varieties
Planting nematode-resistant potato varieties can significantly reduce damage from nematodes. Resistant varieties are
bred to withstand nematode attacks, limiting their spread and reproduction. Although resistant varieties represent one of the most sustainable and effective measures for plant pest control, commercially acceptable potato varieties resistant to plant-parasitic nematodes are extremely limited in the U.S.
Potatoes show damage from Columbia root-knot nematode.