Washington

THE world's top grower of canola crops used to make cooking oil and animal feed is about to lose its biggest export market, just as farmers prepare one of their biggest harvests ever.

Canada - where canola was invented four decades ago by scientists who bred out undesirable traits in rapeseed plants - has become increasingly reliant upon sales to China. The Asian country boosted purchases tenfold in the past decade and now accounts for 40 per cent of shipments. But as at Sept 1, China will impose tighter certification standards on imports of the commodity that may all but halt exports valued last year at C$2 billion (S$2.1 billion).