if you do not feel better after giving up gluten, you might try avoiding all corn and corn products, and all soy and soy products. Corn and soy are most likely GMO. Corn and soy, along with grains, are big triggers for autoimmune disorders.
Here in Kansas, we see television ads for seed that is "roundup ready". Wheat is not GMO, and just like Peterson said in his comments, wheatfields do just fine without needing roundup. They also have no need to genetically modify wheat. Corn, on the other hand, has insect problems, and cornfields can be ruined due to weed infestation.
Personally, I am one of those who sacrifices on other goods so that I can afford to buy organic foods. I grow food and flowers and I raise bees, all organically, and yes it is very labor intensive.
Farmers are very frugal on use of chemicals mainly because more doesn't mean better, it just means more expenses. Homeowners are the worst at over applying chemicals, using them incorrectly, and not keeping accurate records or measuring properly.
I hope this helps.