Adaptation to low fertility hill country in New Zealand of white clover lines selected for differences in response to phosphorus

White clover breeding lines developed as high and low P-responsive, in glas shouse selection trials, were compared, over three years, with 17 other bre eding lines and cultivars for growth in four soil-fertility treatments unde r two defoliation treatments on a hill-country farm. Differences between P- response groups were transitory and biologically insignificant. Selection f or differences in response to P in a controlled environment was not success ful in identifying white clover germplasm adapted to low P hill-country soi ls. White clover breeding lines and cultivars that achieved high growth ove r the 3-year duration of the trial had New Zealand parentage and were all m edium to small leaf types.