I am a firm believer in a distinction between the solutions that
permaculture offers the world -- which are, in my opinion, as yet an incomplete set -- and the permies.com publishing standards.
What I mean by this is that we have ironclad publishing standards ruling out the advocacy of using toxic gick, for example. Probably -- I can't speak for Paul Wheaton, so I'm speaking about my own sure-to-be-imperfect mental model of Paul Wheaton -- this reflects what I imagine to be Paul's view that herbicides and insecticides have no place in
permaculture.
My own view is that we here in North America tend to be fairly rich. If we don't deploy toxic gick to solve a particular problem, we usually can draw upon a wide array of other resources with which to attack it, or we can afford to "take the hit" from not being able to attack it in the most efficient way. And it's Paul's editorial preference to encourage (demand) that the conversation be steered in those other directions in all cases in his forum. The publishing standards are enforced accordingly by staff.
But I am not certain that, as permaculturalists, we've invented a complete suite of permacultural solutions for all problems, applicable in all situations, even for people of the most minimal resources, under the most tight monetary and labor constraints. There might be times where, as sensible and empathetic humans, our advice in a situation would be "Screw the
permaculture. I've searched my brain of everything I know about
permaculture and I came up with nothing that would work as well for you as this
bucket of toxic gick."
Do I think this is likely? Honestly, no. But is it
possible? Maybe. I say this because I am not certain that permaculture
always has an answer for every problem.
Here's the thing: Just because a situation could theoretically happen out in the world, doesn't mean it's appropriate for discussion here on Permies.com. Here in the Cider Press with enough apples, perhaps, although the publishing standards still apply, and the publishing standards do not allow advocating for the use of toxic gick. (Outside the Cider Press we basically don't discuss it at all.)
It is perfectly OK to believe things and do things that don't match Paul Wheaton's vision of permaculture. We don't have to agree with him in every particular. I certainly don't! But in the few areas he's delineated where he doesn't want his forum used to spread notions that he considers nasty, harmful, and bad for fuzzy cute kittens, I just don't feel the need to make Permies.com my discussion forum for discussing those things. It's a big internet! Lots of places to discuss things!
Which is a long way around the barn to your specific very hard problems down there in the tropics. I don't know any good permaculture solutions to fire ants or tropical grasses under conditions of extreme labor shortage and nil mechanization. I honestly don't know enough about the conditions to even have a strong opinion about whether permaculture is likely to offer such solutions. Hopefully some folks will offer some in this thread. But what I'm trying to say is that if you do decide to do things the way your neighbors urge you to do instead of the way the people on Permies think you
should do things, the easiest way to avoid having folks on Permies tell you you're less than perfect is to keep the decision to yourself -- which would in any case be encouraged by the Permies publishing standards.
Just tell yourself "Them people on Permies don't have a complete understanding of the constraints I'm operating under, and they don't have a complete toolbox of solutions applicable to my situation." It may or may not be true; I dunno. But I always just assumed that most of us here on Permies have stuff we don't feel the need to discuss here for reasons like this.