Grain‐yield evaluation of ‘Kopara 73’ and ‘Takahe’ wheat cultivars

Abstract Grain yield performance of two recently released wheat cultivars, ‘Takahe’ and ‘Kopara 73’, was evaluated under field trial conditions during the 1972–1973 and 1973–1974 wheat‐growing seasons. Where powdery mildew ( Erysiphe graminis ) occurred, greater (by 9%) yield increases were obtained with ‘Takahe’ than with ‘Aotea’. The corresponding grain‐yield increase under mildew‐free conditions was 3.4%. Consistent yield increases (mean 6.7%) were measured for the reselection ‘Kopara 73’ compared with the initial bulk ‘Kopara’ release. Relative to ‘Aotea’ and ‘Takahe’, ‘Kopara 73’ mean yield increased by 13.4% and 7.0% respectively. Grain‐yield responses to applied nitrogen were similar for ‘Aotea’ and ‘Takahe’, but both were inferior to that for ‘Kopara 73’. No cultivar x superphosphate interactions were recorded.