手法を比較

	Participatory Varietal Selection	Agroecosystem Analysis
分野	Food Agriculture Studies	Food Agriculture Studies
系統	Process / pipeline	Process / pipeline
提唱年	1996	1987
提唱者	John R. Witcombe and colleagues	Gordon R. Conway
種類	Participatory experimental pipeline for cultivar identification	Systems-diagnosis pipeline for agroecosystem performance
原典	Witcombe, J. R., Joshi, A., Joshi, K. D., & Sthapit, B. R. (1996). Farmer Participatory Crop Improvement. I. Varietal Selection and Breeding Methods and Their Impact on Biodiversity. Experimental Agriculture, 32(4), 445-460.	Conway, G. R. (1987). The properties of agroecosystems. Agricultural Systems, 24(2), 95-117.
別名	PVS, Farmer Participatory Variety Selection, Participatory Variety Selection, Client-Oriented Varietal Selection	AEA, Agroecosystem Properties Analysis, Conway Agroecosystem Analysis, Agroecosystem Diagnosis
関連	4	4
概要	Participatory varietal selection (PVS) is a participatory crop-improvement method in which farmers choose, grow, and evaluate finished or near-finished cultivars on their own fields under their own management, so that the varieties identified are the ones farmers actually prefer and will adopt. Formalized by John Witcombe and colleagues in 1996 as the faster, cheaper sibling of participatory plant breeding, PVS responds to the problem that conventional varietal release — selection on research stations against breeder criteria — often produces varieties that fail in farmers' fields or ignore traits farmers value, leaving the formal seed system with low adoption in marginal, heterogeneous environments. By moving the final stage of selection onto farms and into farmers' hands, PVS rapidly screens existing genetic material for fitness to real growing conditions and real preferences.	Agroecosystem analysis (AEA) is a systems-diagnosis framework, formalized by Gordon Conway in 1987, that characterizes any agricultural system through four properties: productivity, stability, sustainability, and equitability. Rather than judging a farming system by yield alone, AEA treats the agroecosystem as an ecological system shaped by human management and asks how much it produces, how reliably it produces it across seasons and shocks, whether it can maintain output over the long run, and how its benefits are distributed among the people who depend on it. The analyst bounds a system at an appropriate hierarchical level — plot, field, farm, watershed, or region — and uses interdisciplinary teams, ranked questions, and simple structured diagrams to surface the key relationships and the trade-offs among the four properties that drive design and policy choices.