Many cowpeas are grown in this area, but they are often infested by aphids (commonly known as youhan). Only the cowpea in Sanyanquan Township is free of aphids. There is the following legend:
According to legend, when Kangxi was reigning, he was often in private visits. He went to Sanyanquan one day, thirsty and hungry. He went to a farmhouse, and the farmhouse served cowpea porridge as a treat. Kangxi ate very fragrantly, so he asked which beans were cooked in the rice. The answer was cowpeas. Kangxi said that the beans are delicious and should be planted more. The farmer replied: "This bean is hard to grow, which is easy to get aphids." Kangxi said: "You can ensure the planting in the future, and there will be no aphids." After that, the cowpea in Sanyanquan really did not suffer from aphids. The cowpea in Sanyanquan is free from aphids. The reason has not yet been investigated. However, it is obviously unscientific based on the words of Emperor Kangxi.
