In the hills of Yunnan province in south-west China, the growers at Lynch Group’s flower farm were startled last year to receive a barrage of insistent letters from local government officials. The message was clear: the roses and tulips had to go. It was time to grow rice.

The Australian, ASX-listed agribusiness had spent years cultivating the lush mountain valley into a high-tech export hub for ornamental flowers. But under Beijing’s increasingly rigid food security doctrine, even picturesque petals were no match for a national obsession with self-sufficiency in grains and other staples.