Presumably, canned fruit could involve less organic waste as the canner can use ugly fruit that consumers may reject for long enough that it spoils.

I don't know enough to guess whether this is more energy 'efficient', given that we need glass or metal containers, in this case.

Yes, but there's probably less loss & spoilage in the supply chain for canned/frozen/dried/etc.

Same pest/weed control, though, and that's what we were talking about.