> However, those varieties are just extremely unlikely to be as consistently high-yielding as the latest commercial varieties.

Are GMO crops really consistently high yielding? I've heard of some statistics that showed this wasn't actually the case. I don't have any source at hand, but I recall reading that in Europe, where GMO crops are far more restricted than in the US, crop yields actually grew faster over the past decades than in the US, where GMO crops are common.

Also, monoculture makes your crop awfully vulnerable to new diseases. Genetic diversity is much more robust.