History of agriculture
Wild grains were collected and eaten from at least 20,000 BC. From around 9500 BC, the eight Neolithic founder crops – emmer wheat, einkorn wheat, hulled barley, peas, lentils, bitter vetch, chick peas, and flax – were cultivated in the Levant. Rye may have been cultivated earlier but this remains controversial. Rice was domesticated in China by 6200 BC with earliest known cultivation from 5700 BC, followed by mung, soy and azuki beans. Pigs were domesticated in Mesopotamia around 11,000 BC, followed by sheep between 11,000 BC and 9000 BC. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and Pakistan around 8500 BC. Sugarcane and some root vegetables were domesticated in New Guinea around 7000 BC. Sorghum was domesticated in the Sahel region of Africa by 5000 BC. In the Andes of South America, the potato was domesticated between 8000 BC and 5000 BC, along with beans, coca, llamas, alpacas, and guinea pigs. Bananas were cultivated and hybridized in the same period in Papua New Guinea. In Mesoamerica, wild teosinte was domesticated to maize by 4000 BC. Cotton was domesticated in Peru by 3600 BC. Camels were domesticated late, perhaps around 3000 BC.
Agriculture in the prehistoric Southwest
Southwestern farmers probably began experimenting with agriculture by facilitating the growth of wild grains such as Amaranth and chenopods and gourds for edible seeds and containers. The earliest maize known to have been grown in the Southwest was a popcorn variety with a cob only about one or two inches long. It was not a very productive crop. More productive varieties were developed by Southwestern farmers or introduced from Mesoamerica. Beans and squash were also introduced from Mesoamerica, although the drought-resistant Tepary bean was native. Cotton, presumably cultivated, is found at archaeological sites dating about 1200 BC in the Tucson basin and evidence of tobacco use, and possibly cultivation, occurs at about the same time. Agave, especially Agave murpheyi, was a major food source of the Hohokam and was grown on dry hillsides where other crops would not grow. The early farmers also consumed and possibly facilitated the growth of cactus fruit, mesquite bean, and species of wild grasses for their edible seeds.