Villagers pick walnuts with a long pole during a walnut picking festival held in Yi Autonomous County of Yangbi, southwest China's Yunnan Province, Sept. 1, 2018. (Xinhua/Xie Ziyi)

Villagers collect walnuts during a walnut picking festival held in Yi Autonomous County of Yangbi, southwest China's Yunnan Province, Sept. 1, 2018. (Xinhua/Xie Ziyi)

Walnuts are put in baskets during a walnut picking festival held in Yi Autonomous County of Yangbi, southwest China's Yunnan Province, Sept. 1, 2018. (Xinhua/Xie Ziyi)

People pick walnuts with long poles on the opening ceremony of a walnut picking festival held in Yi Autonomous County of Yangbi, southwest China's Yunnan Province, Sept. 1, 2018. (Xinhua/Xie Ziyi)