The warning comes as choking air is blanketing a quarter of the mainland and scientists say they are already seeing the detrimental effects. In He’s tests, chilli and tomato seeds, which normally take about 20 days to grow into seedlings under artificial light in a laboratory, took more than two months to sprout at a greenhouse farm in Beijing’s Changping district.
Membranes and pollutants sticking to the greenhouse’s surface cut the amount of light available to the plants by half, He said.
Depriving plants of light means photosynthesis – the process by which plants convert light to chemical energy – can barely be sustained.
Most seedlings at the farm were weak or sick. “They will be lucky to live at all. Now almost every farm is caught in a smog panic,” He said, adding that the poor seedling quality would cut agricultural output this year.
And if the smog persisted or intensified, the country’s food supply would face devastating consequences, He warned.
“A large number of representatives of agricultural companies have suddenly showed up at academic meetings on photosynthesis in recent months and sought desperately for solutions,” He said.
“Our overseas colleagues were shocked by the phenomenon because in their countries nothing like this had ever happened.”
Greenhouse farms, which occupy more than four million hectares and supply most of the mainland’s vegetables, would be the first to be hit.