Why is there another name in Gannan called the hometown of navel oranges?

There are Hongda, Leng Bo, Huarui, Yun, Ling, Zhang, Nantian, Heng, Exhibition, Victory, Yao, Dexin, Chineydy, Bo Yun, A Zhihua, Yan, Hong Jie, Hao Tu, Zhi Guo, Jiang Chao, Zhe Wei and Bo Shun.