Watermelon?

One thing that really shocked me while in China was how much watermelon Chinese people eat and grow. Even on the first day, just driving around the city you could see wagons and wagons of watermelon. And with every meal we had watermelon too. This made me wonder, why is eating a lot of watermelon a Black person stereotype? Clearly, Chinese people also love watermelon. This is just one thing that puzzled me on this trip.