A farmer prunes pitaya plants at a greenhouse in Jiangwang Town, Yangzhou City, east China's Jiangsu Province, Jan. 4, 2019. (Xinhua/Meng Delong)

Farmers attend strawberry plants at a greenhouse in Huailai County, north China's Hebei Province, Jan. 4, 2019. (Xinhua/Wu Diansen)

Farmers harvest tomatoes at a greenhouse in Handan, north China's Hebei Province, Jan. 4, 2019. (Xinhua/Hao Qunying)

A farmer harvests tomatoes at a greenhouse in Handan, north China's Hebei Province, Jan. 4, 2019. (Xinhua/Hao Qunying)

A farmer plants kale at a greenhouse in Xingtai, north China's Hebei Province, Jan. 4, 2019. (Xinhua/Tian Xiaoli)

A farmer prunes branches for peach trees in Qingzhou, east China's Shandong Province, Jan. 4, 2019. (Xinhua/Wang Jilin)

Staff members take care of cucumber seedlings at a greenhouse in Hai'an City, east China's Jiangsu Province, Jan. 4, 2019. (Xinhua/Gu Huaxia)

A farmer attends strawberry plants at a greenhouse in Renxian County, north China's Hebei Province, Jan. 4, 2019. (Xinhua/Song Jie)

A farmer attends strawberry plants at a greenhouse in Jiangwang Town, Yangzhou City, east China's Jiangsu Province, Jan. 4, 2019. (Xinhua/Meng Delong)