potato blight vs potato murrain

potato blight and potato murrain both are nouns.

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

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

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

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