Here's why:
* Balsa fruit is not a common term. Balsa wood is well-known, but the fruit from the balsa tree is less familiar.
* Rose is a flower, not a fruit.
Possible options:
* You could create a descriptive phrase like "rose-scented balsa fruit" if you were trying to combine the scent of a rose with the flavor of balsa fruit.
* If you're looking for a name for a hybrid plant, you might use something like "Rose Balsam" or "Balsa Rose."
Without more context about what you're trying to accomplish, it's difficult to suggest a single, perfect compound word.