There are a few issues here
Higher wages = higher fruit costs = another reason to import and Australian's have by and large proven over and over again we have very little loyalty to Australian made when price is a factor. Don't be too disheartened, at least Australian and NZ made logo's are proudly displayed in Dubai Supermarkets and usually sell well as considered clean and safe.
If it's economical to bring it in here without it perishing then they're already doing it. We already have oranges from California, garlic from Spain/China/where-ever - you name it, its here.
Stuff like bananas and grapes that have an extremely limited shelf life would have to be air-freighted in though and the cost of doing that versus the cost of paying people properly would be the sole consideration. I'd say it would still be cheaper to pay better wages than to try and air-freight and distribute those highly perishable things.
Aldi have been running adverts on the TV recently proudly proclaiming that they buy their fresh fruit from Australian producers (using bananas as an example). As soon as I thought that I thought - "Well DER, what are they going to do otherwise, air-freight them in when nobody else can do that economically?". Our farmers are generally completely unprotected from foreign competition in this country - if its more economical and practical to bring it in from overseas then that's what happens.
Australia's Mexicans are backpackersNo, more recently they've been Indian workers on student visas who are the Mexicans. They'll work for almost any piece-work rates on offer such as food delivery and Uber-style driving. But they're not prepared to go and pick fruit for some reason, probably because its uneconomical even for them.
Shows you just how bad those conditions really are then doesn't it.
No times change. 20 - 30 years ago we were crucifying the kiwis for working for "sub standard" conditions, wide comb and all that bull $hit that went with it. Even state wise we have workers from one state working in others for lower conditions. My brother when he first worked in WA coming from the East Coast saw all that. NSW workers will acept conditions that WA will not....
Moral of the story, every country has their "Mexians".
As for the Indian's, well the Kerala's used to head to the Gulf states, now the Kerala's expect more, so hitting the western countries.
Global economies is about "harmonisation" of wages for similar work. Why pay $10/h if you can pay $5, why pay $5 if you can pay $1. While the obvious answer is protectionism, I'm not sure how practical that is anymore.
As for Banana's they are the last bastion's of the Australian economy that are protected. So in a heart beat open that flood gate and you will have Thailand and Pilipino banana's for 1/3 the price on your door step. Oranges currently do not earn the same protection.
Airfreight is not an issue and they wouldn't be airfreighted anyway.