potato disease vs potato blight

potato disease and potato blight both are nouns.

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

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

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

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