obtained fertile seed under controlled circumstances.10 This should greatly expand the potential for breeding and hybridizing; ulluco's genetic improvement should be speeded up as a result. In particular, true seed can be used to remove viruses and locate daylength-neutral types.
Because viable seed would help with breeding and genetics, clones should be checked throughout the Andes and efforts made to develop fertile plants. In addition, the seed-producing capacity of wild relatives should be further assessed. Overcoming the sterility barrier would increase the variety of ulluco's colors and other variability to genetic manipulation.11
Shortening the Cropping Cycle There is a need to find types for use in temperate latitudes that mature in a growing season of five months or less, yet are insensitive to daylength.
Increasing Adaptability Clones should be screened for their relative characteristics by rotating them among different growing sites.
Mechanization and Postharvest Handling Methods of mechanized cultivation and harvesting could prove useful. Selection for growth forms adaptable to mechanization is also desirable (sprawling types might not be acceptable, for instance).
Methods of minimizing the scarring of tubers, loss of color, and for minimizing sprouting are also important. Ways to decrease harvesting, storage, and transportation problems could greatly increase the range of markets.
Tuber Quality Consumer acceptability could be enhanced through selection of tubers that, when fresh, have reduced gumminess.
Fertilizer Experiments The plant's fertilizer requirements are little studied, and it seems likely that substantial yield increases can be obtained in the Andes merely through the modest application of manure or fertilizer.
Botanical Name Ullucus tuberosus Caldas
11 Because there is much variation in spite of no known seed formation, there seems a good likelihood of frequent mutation in the vegetative tissues of ulluco. Researchers should keep a watchful eye for unusual tubers.
Somaclonal variation selection is being carried out via tissue culture by R. Estrada in Peru.