Behold the Tearless Onion: Will Monsanto's sweet "EverMild" whet a discriminating palate?

St. Louis-based Monsanto has a plan to make sweet-onion farmers weep.

The seed company last week unveiled a tearless onion that it's dubbed the "EverMild," modeled after the famous Vidalia sweet onion from Georgia.

It's far from the biotech firm's first foray into produce, but com...