The contribution of farmer varieties and wild relatives to the modern varieties being grown in many countries today is clearly evident. All crops have been domesticated by farmers from wild varieties and even today a number of crops, such as sugar cane, tomatoes and tobacco could not be grown on any substantial commercial scale were it not for the crucial contribution, in terms of disease resistance, made by farmers' landraces and wild relatives of those crops. However, no comprehensive agreed estimates exist of the value of genetic material so utilised. Similarly no estimate of the incremental economic value of improved varieties exists.
Economic analysis, however, supports the view that many of those engaged in conserving and developing plant genetic resources for food and agriculture, such as many farmers and their communities, do not receive benefits proportionate to the value of the germplasm originating from their fields. This has been recognized by countries through the FAO resolution on Farmers' Rights which calls for farmers and their communities to participate fully in the benefits derived from the use of plant genetic resources.
The resolution defines those rights as "arising from the past, present and future contribution of farmers in conserving, improving and making available plant genetic resources, particularly those in the centres of origin or diversity" (FAO Resolutions 5/89 and 3/91).