Horticultural Varieties. Selections have been based mainly on the color of the root. In the Andes three main types are distinguished: blanca (white), amarilla (yellow) and morada (purple). Certain strains also differ in flavor, texture, and length of time to maturity. Types with golden roots and orange roots have been obtained by sexual propagation in Brazil. A type resistant to the bacterial disease Xanthomonas arracaceae is also being tested.9
Andean germplasm collections are held in Merida, Venezuela, and Cajamarca, Peru.
Daylength. It is believed that arracacha needs short days for good production of roots, but the range of variation among specimens is unknown.
Rainfall. An even distribution of rainfall seems to be important; ideally, it should amount to 1,000 mm annually and never be less than 600 mm annually.
Altitude. Arracacha is cultivated at elevations from 3,200 m down to 600 m, or perhaps lower. In Colombia, it is said to grow best at altitudes between 1,800 and 2,500 m; in southern Brazil, between 1,000 and 2,000 m.
Low Temperature. A temperature range of 14–21°C appears to be required for best growth; lower temperatures delay maturity so much that the crop cannot be harvested before winter. As noted, the plant tolerates no frost.
High Temperature. Arracacha seems unable to tolerate extended periods above 25°C.
Soil Type. Sandy soils with pH of 5 or 6 are thought to be most suitable; these should be deep and well-drained. Yields are said to be enhanced by fertilizer high in phosphorus and low in nitrogen.