Indian agriculture began by 9000 BCE on north-west India with the early cultivation of plants, and domestication of crops and animals. Indian subcontinent agriculture was the largest producer of wheat and grain. They settled life soon followed with implements and techniques being developed for agriculture. Double monsoons led to two harvests being reaped in one year. Indian products soon reached the world via existing trading networks and foreign crops were introduced to India. Plants and animals—considered essential to their survival by the Indians—came to be worshiped and venerated.