Walmart has 10x as many stores in the US relative to China. It's 5,358 in the US¹ vs 426 in China².
Does Walmart have leverage in China to force this on growers? They do in the US.
1. https://corporate.walmart.com/our-story/locations/united-sta...
2. https://corporate.walmart.com/our-story/locations/china#/chi...