When and were did native americans first teach european settler to grow corn?

During the 1400s in the West Indes - It was the Native Americans who actually taught the Europeans how to grow corn. When Columbus arrived in the West Indies during the late 1400s, the Natives there gave him corn, which he took back and introduced to Europe. 

  the domino theory states that  if one country in a region came under the influence of communism, then the surrounding countries would follow in a  domino  effect.