U.S. wheat exports face a significant downturn after the Wheat Quality Council flagged that spring harvest yields in North Dakota could be the lowest since 2008. The past year has seen a bumper export season with shipments in May 80% above a year earlier and the highest since January 2015 in volume terms. There is also a long-term risk to weaker deliveries this year, with the Mexican government mulling allowing imports from Argentina as part of its food diversification strategy.