Design (short description):
The progenitors are grouped in three crossing blocks according to their protein electrophoretic patterns and parentage to increase heterosis, some 700 crosses are done each year with a production of about 500,000 seeds. Systematic transplanting of 100,000 seedlings and field multiplication and selection is done for early generations. Flexible progression of clonal multiplication is performed except for first year clones, where one tuber is always selected in the field and 4-5 cuts are planted the next generation. Growers' trials are performed at the fourth year in the field with 25 plants in one row plots with four replicates in two locations. Advanced clones are evaluated accordingly in a national network with 15 locations; seventy to eighty clones are included in these trials every year.