potato blight vs potato disease

potato blight and potato disease both are nouns.

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

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

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

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