Infographics: Why are apples from Yan'an so popular?

In early winter, the fragrance of apples fills the air of the Loess Plateau in the northern part of Shaanxi Province in northwest China. The apples grown in the mountains in Yan'an city, Shaanxi, are sold around the country and the world. Yan'an apples have found their way to the dining tables of Chinese households, reached more countries and regions involved in the Belt and Road Initiative (BRI) through freight trains, and even travelled to China's space station.

How did Yan'an apples get so popular? What are the secrets behind the growth of the apple industry in Yan'an?