Field library

Late Blight

Dark water-soaked patches spread inward from the leaf edges, and on a humid morning you can see a white fuzzy ring on the underside. In foggy December and January weather it can take a healthy potato field to a black, collapsed crop within a week. Tubers rot in storage afterwards.

How to scout

Check the lowest leaves in the dampest, shadiest corner of the field first — that is where it always starts. Look early in the morning while the white growth is still visible.