A political dispute between China and Canada over the arrest of a Huawei executive is slowing canola shipments through Chinese ports. Shipments are taking longer to clear Chinese customs and obtain GMO permits needed to import genetically modified crops, including canola. China buys some $2.5 billion of Canadian canola per year, and the delays have caused some importers to hesitate to buy from their biggest supplier. Canola futures prices have stayed firm since the arrest, but brokers say worries about China have caused prices for canola to miss out on a boost in sales of other oils.