The history of maize breeding methods in the USA is reviewed to examine the
question of types of maize cultivars in sustainable agriculture. The yield potential of OP
cultivars was much higher than national average yields prior to 1930, but hybrid cultivars
today often out-yield OP cultivars by 50–100% or more. However, rates of gain for yield
using recurrent selection on populations appear equal to that recorded for commercial hybrid
breeding. The inbred-hybrid method, while successful, was not “the only sound basis” for
maize improvement, as evidenced by later experiences in the United States and worldwide.
It appears that maize breeders have practiced objective science and achieved concrete goals,
although personal interests and goals clearly direct the work at times. As society looks for
tools for sustainability based on achieving multiple goals, a special dedication to scientific
validation and broad objectivity may be required. The potential for OP cultivars today is
evaluated and research questions are identified.