Description:
During 1969-1978 several cycles fo recurrent selection were performed on a germplasm base (U.S., Andean, and European) and named Cold Tolerant Composite, CTC-1. Phenotypic recurrent selection for field cold-tolerance in early spring plantings and early silking for 4 cycles was followed by 3 cycles of progeny test selection using seedlings in growth chambers at 4.5 deg-15.5 deg daily range. Some tests were for general combining ability for cold-tolerance in diallele, and topcrosses to the Swiss variety Rheintaler. Some of these were added to the breeding pool, and this recombination became this selection in 1978.