Are you talking about allowing fusion energy that is good for life, but shielding from fusion energy that is dangerous for life? Or are you talking about converting fusion to electricity so we can power white light "bulbs" for plant needs?
What do you mean?
I mean that with unlimited energy one can synthesize almost anything a human needs to stay alive including nutrients. No old-fashioned sun required.
You know this? Or you are hopeful?
If we do get commercially-viable fusion, then yes, it is essentially limitless free clean energy. Assuming everyone gets access to it and it's not just held back by the powers that be.
Fusion is essentially the opposite of the nuclear power that we have now, fission.
Fission creates hugely dangerous waste, is non-sustainable because it uses unstable heavy elements as source material, and can have runaway chain reactions, as we have seen.
Fusion sticks small atoms together to create energy. Its srouce is deuterium, which can be extracted from water. Its waste product is mostly helium, non-radioactive and safe. Chain reactions are impossible because you need a constant input of new fuel.