Want to know my record for coming back to my crops and they're gone? 10 minutes. I logged off to head to a lecture, logged back in 10 minutes later and all my watermelons were gone. It's ridiculous. Occasionally I've been able to scare people off or convince them to leave my crops alone, but if you're an outlaw in a foreign nation and get aggroed by every tom dick and harry, you start losing patience real fast. (especially when Amakna is the only nation you can grow these crops)
The thing is, it wouldn't be as irritating if the high level crops didn't take over an hour to grow in the terrible weather (something you can't really control) just to find that it was all for nothing. I spend a day harvesting enough seeds in my bag to be able to plant them in Amakna, and then less than half actually plant and then they're taken by someone else.
Anyway, what I'm trying to say is if you want to grow something, grow it yourself. But most people will probably look at this and go, "Oh that's just how the game is, deal with it." I do deal with it, and I'm suggesting that we have some way of protecting the crops that we grow instead of sitting around for several hours in one spot and not leaving because you know as soon as you leave someone will come along and take them.