Significantly or notably, I mean?
Is it worth using as a rootstock for others?
Or is its resistance largely a myth or of minor significance?
Are nematodes a significant problem with growing figs?
I have not seen the problem in my area but appreciate that there may be areas that are plagued by this.
A follow-up question;
Vinifera grapes are grafted on various disease resistant and various vigour controlling rootstocks. (s04, 3309 ...)
Are there proven rootstocks that are used for figs?
Root-knot nematodes are probably the main limit to edible fig growing in the ground in warm, moist, sand soils, being most of the SEUS coastal plain.
Most of the non-"carica" Ficuses that seem to tolerate nematodes are tropical and thus not of much use, even experimentally, north of southern Florida. They are also much larger trees. (One native fig trees has small but decent-to-eat fruit, if you can beat the squawking flocks of feral? parrots to them.)
LSU Purple is a very vigorous grower. It is the strongest grower of the fig trees that I have. Because it is such a strong grower it should be able to handle RKN better than most ficus carica varieties. The nematodes will go after the roots, but if the tree is able to keep growing new roots it should be able to withstand the nematodes as long as the infestation is not too severe.
The LSU.Purple fig has long been 'touted' as RKN 'resistant' (but not immune).
So far I have not seen any scientific study/report on the subject.