Big Apple
"The Big Apple" was popularized as a name for New York City by John J. Fitz Gerald in a number of horse-racing articles for the "New York Morning Telegraph" in the 1920s. The earliest of these was a casual reference on 3rd May, 1921:
Economic botany
Apples are not native to North America, but today the North American continent boasts the greatest diversity of apples in the world. Part of this is due to "Johnny Appleseed," real name John Chapman. Chapman spent 48 years travelling all along the American northwest spreading apple seeds and planting trees. While apples come in literally thousands of varieties, the majority of the apple market is based on three: Red Delicious, Golden Delicious, and Granny Smith.