Relationship among planted and harvested kernel weights and grain yield and protein percentage in winter wheat

Summary Wheat (Triticum aestivum L.) kernel weight is an important yield component and seed quality factor that appears to be declining with recent cultivar releases in the major U.S. wheat region. The objectives of experiments were to detmrmine the relationship between planted and harvested 1000-kernel weights and their effect on grain yield and grain protein percentage. Twelve popular hard red winter wheat cultivars were grown with recommended practices at 10 Kansas locations for three years. Rank correlation coefficients between kernel weights and grain yields and protein percentages were calculated.Correlations of planted and harvested kernel weights over all cultivars with grain yield were inconsistent, being positive for some locations and years and negative for other locations and years. Planted kernel weights and grain yields of individual cultivars were not related, but harvested kernel weights and grain yields were correlated positively for eight of the 12 cultivars. Harvested kernel weights and grain protein percentages frequently were correlated positively at individual locations, but always were correlated negatively for individual cumtivars. It was concluded that high stable harvested wheat kernel weight is important as a component of grain yield under a range of environments and that improving this trait would benefit all segments of the wheat industry.Contribution No. 84-395-J, Department of Agronomy, Kansas State University, Manhattan, Kansas 66506 USA.