“Terms sometimes used interchangeably to describe the main ways farmers acquire and disseminate seed: their own harvests; exchanges with relatives, friends, and neighbors; and local markets. These seed systems, which can diffuse local or modern varieties (which are recycled), tend to be governed by local norms of practice rather than official or government standards. Seed is not backed by formal certification. Worldwide, small-scale farmers source about 80% of their seed from these systems [in the case of roots, tubers and bananas this can be up to 100%].”
References
Sperling, Louise. 2008. When Disaster Strikes: A Guide to Assessing Seed System Security. CIAT Publication. Cali, Colombia: CIAT. http://ciat-library.ciat.cgiar.org/Articulos_CIAT/sssa_manual_ciat.pdf