Primitive cultivars that are selected and cultivated by famers for many years are

Primitive cultivars that are selected and cultivated by famers for many years are Landraces.
Landraces are defined as dynamic populations of a cultivated plant with a historical origin, and distinct identity, often genetically diverse and locally adapted and associated with a set of farmers' practices of seed selection and field management as well as with a farmers knowledge base.
A landrace is a dynamic population of a cultivated plant that has historical origin, distinct identity and lacks formal crop improvement, as well as often being genetically diverse, locally adapted and associated with traditional farming systems.