Mon Nedarim 57

If one makes an oath on these fruit, he's forbidden to partake in what grows (if you plant them) and what it's exchanged for.

Ran explains since you specify the fruit by saying "these fruit." Therefore, your stating that they're like hekdish, thus we treat them so to forbid the growth and the exchange. However, if you just make an oath on the type of fruit in general, this won't apply.

However, Ran asks on this, since in an earlier Perek Rumi b. Chama inquired if this only applies to the one who makes the Neder, since he can Assur other people's property on him, so too they can Assur himself on what grows and is exchanged, despite that it's not his yet. Or any Issur Hannah has a Halacha of Hekdish and therefore this would apply to all. The second side obviously applies even if you don't specify the fruit, since it applies to all Issur hanah. Since Rami b. Chama doesn't explicitly ask if the Mishna specifying "these" is not exact and refers even when there is no specification, thus we must assume that he wasn't in doubt. So we must say that even his first side refers even when he doesn't specify. Thus we see that this applies even without specifications.

The Ran answers: really our Mishna needs specification for the one who made the Neder. Therefore he can Assur him not only what he exchanged the object for, but even what others exchanged it. Rami b. Chama only asks if we say that for others that didn't make the Neder, do we say that we permit all exchanges, since the Neder can't go on them. Or do we say the Halacha of Issur hanah that he's forbidden with what he exchanges the item for. However, we never had a Hava Amina that it should be forbidden to them what others exchanged it for.