Potato brown fleck
Potato brown fleck is a disorder, not a disease.
Cause
Flecking caused by high soil temperatures during bulking. Calcium and/or boron deficiency is also believed to be involved.
How it spreads
Being a disorder, brown fleck does not spread.
Crops affected
Potato
Control
In the future, ensure calcium and boron levels are adequate, and do not plant susceptible varieties, such as Winlock, to mature in hot weather.