As I see it, for whatever help it is in controlling citrus disease (or not), the new requirements for nurseries growing citrus trees has been a big boost to the large growers. The competition from small growers has been eliminated. All out of state competition has been eliminated. The added cost of doing business can be passed on to the consumers, and fruit growers, because their choices have been severely limited. The growers have put up the screen houses and or greenhouses, which I am sure can also provide freeze protection when needed, so in the end, I suspect that requirement will become an advantage too. I suspect the complaints from the big nurseries are crocodile tears.
Ned