potato disease vs potato mildew

potato disease and potato mildew both are nouns.

Word	Noun	Adjective	Verb	Adverb
potato disease	Yes	No	No	No
potato mildew	Yes	No	No	No

As nouns, potato disease and potato mildew are synonyms defined as:

Other synonyms of potato disease include potato blight, potato mold, potato murrain.

potato disease (noun)	potato mildew (noun)
a blight of potatoes	a blight of potatoes