Canola is piling up in Canada, with supplies only set to grow after China kicked off an anti-dumping investigation.

Stockpiles of the commodity used to make cooking oil and animal feed surged to a four-year high of 3.1 million metric tons by the end of July, according to Statistics Canada data Monday. The 67% jump from a year earlier came ahead of this year’s harvest, with farmers already gathering the new crop.

China, the world’s top canola importer, announced a probe on Canadian shipments last week in response to the Trudeau administration’s tariffs on China’s electric cars and aluminum. Canola exports now are at risk as traders await details on any restrictive measures imposed by Beijing.

Canola futures rose as much as 2.9% in New York, after posting the biggest weekly decline since 2022 last week.