The Columbian Exchange
In 1492, Christopher Columbus and his crew of ragtag, starving, near-mutinous sailors washed ashore in the Bahamas, "discovering" the New World and claiming ownership of it for the Spanish monarchy. The Taino indians Columbus encountered—whose homeland he claimed for Spain—must have thought he was mad, suffering delusions of grandeur.
Tomatoes were the new world product when ever columbian came back tomatoes made its way to the old world u could do a lot with tomatoes like put ketchup on your hot dogs,burgers or anything u want to
Grapes are an old world product now they are new world they really don't affect us they just give us new products to eat and u could make grape juice with grapes
Small pox are from the old world it can really affect the new world because u could die from this and u wouldnt wont this in your world cause when one person has it everyone will get it
Malaria is also a old world disease it kinda like small pox just not as worst i would rather have malaria cause small pox can kill u faster than this will
Suger cane is also from the old world it wouldn't affect the new world because all it does is just make food sweet and make them taste better