Seed systems are a vehicle for dissemination of propagules, based on reproductive organs like true seeds or vegetative organs like cuttings or seed tubers. However, seed systems are also vehicles for transgenerational transmission of pests and diseases. Finally seed systems are a response channel for deployment of interventions, for example through the introduction of new cultivars or extension information.
In the Western World seed systems are highly developed with well organised (often multinational) businesses and strong governance systems based on national or international laws. In contrast, in many low-income countries almost all seed is recycled by farmers, without formal quality control. Seed quality encompasses physical, physiological, genetic, and phytosanitary aspects. Producing, storing and distributing high-quality seed requires insight in agronomy and physiology of crops and propagules, but also in pests, diseases and their vectors and in the social structures that govern the seed system. Interdisciplinary and transdisciplinary research in synergy with social sciences is crucial.