Typically, some farmers adopt it quickly, while others wait for extension or the results of their neighbours to convince them to do so. They are crucial to facilitating the dissemination of new technologies and their learning and adoption by farmers. They provide a link between the generation of innovations by national and international research institutions and their mastery and adoption by producers at the farm level. They have been introduced on less than one third of the area planted with cereal grains in the developing world (Zepeda, 2001).