China is once again imposing restrictions on Canadian canola over concerns of blackleg, a fungal disease that destroys the crop. The Chinese did the same thing six years ago and Canadian researchers, including the University of Guelph’s plant agriculture professors Dave Hume and Mary Ruth McDonald, are wondering if the recent decision is based on science or politics. The two U of G profs weighed in on the issue in an article appearing in The Globe and Mail. Hume, a crop consultant and retired crop physiology professor, called China’s move “déjà vu,” while McDonald said she was baffled and that nothing has happened in recent years to suggest blackleg is a bigger problem than it was previously.