International institutions such as the International Potato Center (CIP) strive to provide "global public goods" in the form of improved technologies applicable to large regions of the developing world. To identify priorities for potato improvement, CIP conducted a survey of knowledgeable potato scientists in developing countries to elicit their perspectives on the most important constraints facing poor and small-scale potato growers in their countries. Respondents scored productivity or other constraints according to their importance in the region or country where they worked. Mean and weighted mean scores were estimated to provide a group judgment of the most important constraints facing potato farmers in developing countries. The five highest-ranking needs described by the survey respondents are: (1) control of late blight fungal disease (through varietal resistance and crop management); (2) improved genetic material for high and stable yield potential, suitable for consumption (new cultivars and prebreeding); (3) improved supply of quality potato seed (seed systems management and seed production); (4) control of viruses and their vectors (through varietal resistance, seed production and crop management); and (5) control of bacterial wilt (through varietal resistance and crop management). These five needs were ranked high in all or most of the potato-growing regions of Asia, Africa and Latin America. Exceptions were bacterial wilt control, which was a top-ranked need primarily in sub-Saharan Africa and east and southeast Asia, and virus control, which scored relatively low in Latin America. Priority rankings did not change when survey responses were weighted by potato area and poverty incidence of the country for which respondents reported.
