This prophecy details a blight that will strike all grain crops either in the USA or worldwide, the latter being more likely given rumors that this has already started happening in Africa. It will strike and ultimately destroy ALL GMO crops, and a wide swath of the hybrid seeds. Basically any seeds created using genetic modification via laboratory or non-natural practices will die. Seed varieties, including hybrids created using natural breeding, and all heirloom and organic seeds will be preserved.
If there was any artificial human intervention involved in the process however, all of those varieties will die. This will cause a massive spike in the demand for heirloom and organic seeds, likely making them worth tens of thousands of dollars per pound of seeds. For example, a simple 1oz package of carrot seed could begin selling for as much as $4000 each.
Edit (2020-02-05): I'm seeing a bit of a pause in the fulfillment of this prophecy, so its status is being set to "partial fulfillment" until more significant forward motion on its fulfillment resumes.
(*Do you have a better description, or did you find an error? Please let me know.