Isaiah 5:24 (King James Bible) so their root shall be as rottenness and their blossom shall go up as dust
The 1830 typesetter accidentally changed the singular blossom to the plural blossoms. He did not make this change by reference to his King James Bible, since the King James Bible has the singular blossom. But the singular is expected since the parallel clause also has a singular subject (“their root”) in the King James translation as well as in the original Hebrew.
The Book of Mormon text, however, removes one aspect of the parallelism between these two clauses—namely, the as in the first clause (“their root shall be rottenness”). The King James translation here reflects the parallelism of the Hebrew original (both words for rottenness and dust take the prefix k-, which means ‘as’). In 2 Nephi 15:24, the as in the second clause is kept, probably because it seems necessary; the reading “and their blossom shall go up dust” is awkward, if not impossible. Of course, an as in the first clause could have been accidentally dropped in the early transmission of the Book of Mormon text. (See 2 Nephi 9:16 for a list of instances where Oliver Cowdery accidentally dropped as as he copied from 𝓞 into 𝓟.) On the other hand, since here in 2 Nephi 15:24 the reading without the first as is possible, it is perhaps best to follow the earliest textual sources and retain the Book of Mormon reading without the as. It is also worth noting here that the original 1611 King James Bible did not have the as either.
Summary: Restore in 2 Nephi 15:24 the singular blossom, the reading of the printer’s manuscript as well as the King James text (and the original Hebrew); maintain the first clause without the as (“their root shall be rottenness”), in accord with the earliest textual sources for this passage in the Book of Mormon.