Sweet Potato Research

Asian Vegetable Research and Development Center

AVRDC has focused on the areas of breeding, entomology, pathology and physiology in their research on the sweet potato. The breeding program has focused on hybridization of varieties to select for good performance under hot and wet conditions, resistance to sweet potato scab, improved dry matter yield and good eating quality.

The seet potato weevil is the focus of much of AVRDC's entomological research. After discovering a significant positive correlation between root yield and weevil damage AVRDC researchers have discarded the possibility of breeding agronomic cultivars with weevil resistance. Thus they have invested in other strategies to control the weevil, one of which is to use alternative host plants. Five species of Ipomoea have been found that harbor sweetpotato weevil.

Researchers successfully controlled sweetpotato weevil in farmers fields on Penghu Island using a variety of integrated pest management techniques including: crop rotation, control of alternate Ipomoea hosts, stirring of soil to cover cracks, and continuous trapping of weevil males in pheromone traps. AVRDC's work with sweet potato pathology has focused on methods of controlling viral diseases. They performed an experiment to verify the comonly held notion that seeds do not transmit viruses in indicator hosts, and found the supposition to be true. Other work included efforts to examine the effect of environmental conditions on growth factors which contribute to yield. They discovered that high temperatures and flooding tend to cause the diversion of dry matter to the storage root.

for more information contact:

Office of Information Services
the Asian Vegetable Research and Development Center
P.O. Box 42
Shanhua, Tainan 74199

The International Potato Center (CIP)

One of CIP endeavors is to preserve sweet potato germplasm. Since 1985 when CIP was given the mandate for this crop within the CGIAR system of international agricultural research centers, over five thousand accesions have been collected and stored at their gene bank in Peru. Most have come from the Americas. CIP has also taken responsibility of the collection of African materials at International Institute of Tropical Agriculture in Nigeria.

CIP is working with scientist in developing countries, with the International Board for Plant Genetic Resources, and with other international organizations to collect and preserve the wide diversity of varieties grown and preserved by farmers. Over 400 accessions have been collected by national programs in Kenya and Uganda alone, and nearly 300 have come from Rwanda. Orthodox seeds are also being collected and cultivated to obtain polycrossings. Seed is taken from these crosses and stored at low temperatures.

CIP is assisting national programs to characterize and evaluate the varieties in their collections, and to survey farmers about their uses and preferences. Accessions must first be given proper taxonomic identification, and then the characterization of the cultivar must include descriptions of its floral, plant and storage root characters as well as other traits needed in current breeding programs. These criteria will be eveloped to direct the introduction and testing of breeding lines from other countries.

Training courses on sweet potato have focused on commercialization, seed produciton, and tuber production.

for more information contact:

International Potato Center
Apartado 5969
Lima Per
Telex: 25672