View article

Traditional agricultural systems in less developed countries (LDCs) maintain not only the germplasm of local varieties of ancestral crop populations (landraces) but also the human knowledge and behavioral practices that reflect a long coevolution between crops and human populations. The germplasm of crop landraces provides the material from which high-yielding seed varieties (HYVs) have been developed by international and national agricultural research centers. Farmers' knowledge and behavioral practices, in turn, shape the manner and extent to which these new varieties are adopted and integrated back into the traditional farming system. Although farmers in traditional agricultural systems frequently adopt new seed varieties and other modern inputs, many adopters also continue to cultivate local varieties. High-yielding varieties are introduced into agricultural systems where high levels of crop diversity …