White Nodules on Potatoes After Wet Weather: Physiological, Not Fungal

After extremely wet weather, your early and second-early potatoes are covered in tiny (1 mm) white nodules that rub off easily. The skin underneath appears unaffected.

Diagnosis

This is likely a physiological response to excessive moisture and possibly excess fertilizer—not a fungal disease. True fungal lesions would develop sunken spots after storage.

What to Do

• Store the potatoes normally and monitor.
• If sunken lesions appear where nodules were, it may indicate a secondary issue; contact for a preventive program next season.
• Otherwise, the tubers are safe to eat.

Improve drainage and avoid over-fertilizing in future plantings to reduce recurrence.