Some Chinese buyers have canceled corn purchases from the United States and started to buy corn from rival supplier Ukraine, as Beijing announced rather high requirements for the processing of genetically modified crops. Traders this year have been more inclined to buy corn from Ukraine as it is non-GMO and doesn’t require the (processing) permit. Any prolonged shift by one of the world’s top corn importers would unnerve U.S. farmers as they prepare to harvest a bumper crop this year and could potentially mark a new front in trade tensions festering between China and the United States.