> But tight margins for a single family owned farm could vary dramatically to that of a corporate farm, I would estimate.

You're right, large businesses have economic advantages, but I think you may have misunderstood me. The large farms have tight margins. The small farms have no margins. I'm not sure why a large operation would throw their profits away to applying glyphosate for, in this context, absolutely no reason.

> don't they still have to start in the south and work their way north as the harvest seasons shift?

Are you sure you're not still thinking of the harvest crews that provide custom harvesting services to other farmers? They absolutely start in the south and work north. These businesses generally do not manage the farms themselves, however. They serve other farmers, typically smaller ones who do not have the acreage to justify the capital expenditure for harvest equipment (the cost of new combine alone is rapidly approaching the $1,000,000 mark).

Assuming we're still talking about the US (like you said, pasta does not cause the same symptoms in other countries) I have found no single grain farm that is large enough to span that large of a distance. Do you have a particular business in mind that I may have missed?

> it looks like glyphosates applied at the end of the harvest increase yield.

Increase yield at the end of harvest? I mean, I guess. Glyphosate has mass and adding it to the storage bin will increase the stored weight by some amount. You'd make a lot more money selling the glyphosate in its pure form though. It's value by a given mass far exceeds that of wheat. I don't think this is what you really meant.

If you meant soon after planting, I found one study that suggested that a low dose in the 3rd leaf stage could stimulate growth to increase yield. The study was also dated 2016. This is the first I heard of it, and I expect most farmers are in the same boat. The study said that previously this was thought to not be possible. Of those who have tried it, we're talking, what, realistically one crop? Did your friend's problem just start recently when it was previously not an issue?

I'll add that I'd need to see a ~5% yield bump just to cover the cost of application, never mind making additional money. Higher yields alone does not necessarily make it worthwhile, and I'm not convinced that even with the findings of this study that it would be worth it. There are plenty of things you can do to increase yield, but it's still a cost/benefit thing. The goal of farm business is maximizing profit, not maximizing yield.

Also, you didn't answer if your friend's problem was limited to durham wheat or not. You originally suggested that might be the case, but haven't elaborated since. It's fine to look at roundup as a potential reason, but why not discuss all of the potential variables?

> One last link, even Bob's Red Mill says he can't be sure if there glyphosates in the wheat he sells. (non-organic)

Which is quite telling. When you deliver a load of wheat, the destination will take a small sample for further analysis. If that small sample contains glyphosate, they will know about it. The problem is that when you have grain mixed from many sources, that small sample may not be the area of the load that does contain traces of glyphosate. As such, it is quite possible for some to slip through.

The fact that we're only talking small amounts slipping through and not entire loads "doused" in it, goes to show that the practice is not common, which is what I said from the start.