Sorry, but it's not our problem.
Wipe out the crops and let them figure out what else to grow. Either the world is serious about the drug problem, or it isn't.
Yes, a very good idea is to increase the cost of cultivation the crop, and force them to use alternative crops. Perhaps https://en.wikipedia.org/wiki/Saffron ?
If you read this http://link.springer.com/article/10.1007%2Fs11046-006-0014-0#page-1 and do the opposite (the article describes how to protect the crop) and spray the fungus on the fields it might work.
“Wipe out the crops and let them figure out what else to grow. Either the world is serious about the drug problem, or it isn’t.”
That’s about as simple as “regime change”. You can’t just wipe them out once and they are gone. The residents will just grow another round of the same stuff,since this has been a cash crop for a long time over there. It’s capitalism 101: they produce a good or service that people will pay money for.
As long as there is a Hugh demand the price to eradicate it will be huge, i.e., you have to kill all the growers. And that’s too high a price to pay.