@hightor,
Again...you'll notice it is the trade organizations, not actual wheat producers who are complaining.
He didn't send a signal that our wheat is not a valued commodity, he said Japan doesn't truly value it as other customers do, but they are nevertheless buying it.
How could that comment possibly impact the value of American wheat?
I don't know who buys our wheat other than Japan, but let's say Iceland does. The buyers their (if they even heard the comment) aren't going to think "Geeze we've always thought American wheat was great but if the Japanese don't really need all that they buy, we better look to other markets!" Only someone with an animus for Trump or a job that depends upon him rising to every real or perceived critique of his client, who interpret Trump's comment to mean he was saying Japan is buying
inferior wheat because of his prowess at deal-making.
I would not have made the comment because it could reflect poorly on the Japanese, not American wheat. Despite what you might think, he's not a fool. He knows the Japanese aren't "stupid" enough to disrupt trade relations with the US because of a comment they might not appreciate. He made it for domestic political purposes. Every president we have ever had has kept politics in mind in making decisions and statements. Foreign leaders are more than happy to work with us and then make disparaging comments about us to their people...for political reasons.
I can assure you that the rest of the world doesn't tune in to Trump's rallies. and my bet is that the vast majority of Japanese citizens wouldn't have a clue about what we are discussing.