I've seen some serious articles that suggest that wikis, in appropriate circumstances, can be highly accurate and self-correcting. Important variables involve the responsibility of the editors (ongoing demonstration of responsible actions), and the "activeness" of the community of editors, as well as the level of expertise among the editors. Those articles still point out that at any one point in time, there may be wild inaccuracies. But given the right community of editors, over time they tend to self-correct. (I don't know if I can find those articles any longer... I recall that one of them was published by an information scientist at IBM's Watson Research laboratory, and another was by an author at one of the universities in England, I think Cambridge but may have been Oxford. I suspect the US Library of Congress may have also studied this).
As others have pointed out, I think that Jon's "Varieties" pages are probably the most comprehensive listing of synonyms for Ficus carica varieties. But I'd go further to suggest that if it's too much for just one person to maintain (and I think it is), then another step would be if Jon invites others to become co-editors. He may well be thinking along those lines with the F4F foundation. The set of people he invites as co-editors would become the "community of editors" for such a wiki (if he chooses to put those pages into a wiki site form, which imo is not a bad idea).
Of course, successful growth and ongoing accuracy depends quite a lot on who makes up the community of editors. It also needs to be a large enough set, an active enough set, a responsible enough set (especially this bit about responsible action, despite the subjectivity of such initial decisions), as well as people with "enough" expertise. Interestingly, the characteristic of responsible actors is more important than having every editor have significant level of expertise. The set can be quite large.
My point is just this: Having a person/committee select the editors (members of a community of editors) is likely more workable for this sort of effort, rather than selecting the edits.
I offer this thought for the F4F foundation folks, in choosing what they plan for the ongoing maintenance of Jon's excellent Varieties pages. It is clearly "too big" for just one person. If they choose a wiki format for the future, I suggest choosing to invite editors to the community of editors based on judgments of responsibility as well as a modicum of expertise. A large and vibrant community of responsible editors who remain active, is preferable to a small community of people with very high expertise. Even if many editors have only moderate amounts of expertise... if they are chosen because they act responsibly, they are a help rather than a hindrance. Obviously, it's helpful to have some with much expertise and knowledge too. The community, if appropriately chosen, will tend to identify those who make erroneous updates over time. (As well as tending to correct the errors made by the editor-in-error). The irresponsible actors become banished from the community. With a properly active and responsible community, it can work out.
Mike central NY state, zone 5a