I will not buy produce from Mexico. May not be worse than California, but I dont care.
I also try to avoid Mexican produce. Unfortunately, almost all tomatoes available in supermarkets in my area (Southern California) are from Mexico--even those at high-end supermarkets like Whole Foods, Trader Joe's and Sprout's. Virtually all Roma tomatoes are from Mexico.
Sprout's and Trader Joe's sometimes carry beefsteak and heirloom tomatoes grown locally or imported from Canada. Otherwise, I look for them at farmer's markets.
I dont buy even organic from Mexico because everything in that country can be bought. Im sure organic labels as well.