I have seen this addressed in the archives, but was unsure of what the final consensus was. From perusing what is available at helpmefind, it would seem that many diploid species roses are self-sterile. However, I was unable to find that information for the weedy (and disease prone) multiflora that grows everywhere here in the midwest. Is emasculation of the bloom necessary with multiflora, or just a cover after pollination, until it is no longer receptive to pollen. The flowering parts are so small, it would certainly be much easier, if that were the case.
Background reading, full paper.
Great paper, thanks Dr. Kuska!
Thank you, that was exactly the kind of information that I was looking for!