On which continent did the earliest farming begin?

The earliest evidence of systemic agriculture is in Asia, in the modern-day Middle East, in the so-called "Fertile Crescent" that begins in modern Iraq and arcs westward into modern-day Syria. While some isolated evidence has been found that strongly suggests people in the region were beginning to engage in plant cultivation more than 20,000 years ago, the accepted time period for the development of organized agriculture is around 11,000 B.C.E.. Within a thousand years or so of this date, agriculture developed independently in the Yellow River Valley, Central America, and the Indus River Valley, among other places. It is important to note that due to this fact, as well as the fact that the dates are so imprecise, that it is hard to say, and is really not all that meaningful to say, definitively who first developed agriculture. Indeed, there is significant disagreement over when, and where, agriculture developed. However, the development of agriculture was an event of profound importance. It paved the way for enormous changes that included the emergence of stratification, literacy, diseases, and significant technologies.
https://www.theguardian.com/science/2015/jul/24/archaeologists-find-possible-evidence-of-earliest-human-agriculture