R. Michael Bourke
Sweet potato production and research work in Papua New Guinea is reviewed. The estimated annual production is worth over K200 million. It is the staple food in most of the highlands and parts of the lowlands. In the central highlands, it provides between 65% and 90% of people's energy intake. Aspects reviewed are the significance and distribution of the crop, the timing and effect of its introduction, the crop's ecological place and role in various cropping systems, cultivars grown, cultural techniques used, systems of harvest, crop yield, major pest and disease problems, and future prospects. Some 180 agronomic field trials have been carried out. Research work reviewed includes cultivar, inorganic fertilizer, method of cultivation, plant density, effect of weeds and weedicide, time to maturity, method of harvesting, tuber protein content analyses, storage and other agronomic studies. Also reviewed are the possible manufacture of a dried sweet potato product, little-leaf disease studies and work on sweet potato as a stock-feed. The status of current research is mentioned. Available data on the importance of sweet potato in people's diets and agriculture, number of cultivars used by different groups and yields under subsistence conditions are presented.