Cereal Chem 62:463-467   |  VIEW ARTICLE
Hardness of Winter Wheats Grown Under Widely Different Climatic Conditions.

Y. Pomeranz, C. J. Peterson, and P. J. Mattern. Copyright 1985 by the American Association of Cereal Chemists, Inc. 

Fifteen winter wheat cultivars or selections from the 15th International Winter Wheat Performance Nursery grown at 11 locations in the USA, Europe, and Asia, were analyzed for protein content, kernel weight, and hardness. A total of 161 samples were evaluated. Hardness was determined by four methods: time to grind, resistance to grinding, particle size index (PSI), and near-infrared reflectance (NIR) of ground wheat. The effects of location were larger than those for variety on protein content and 1,000-kernel weight. Variety had a much larger effect than location on wheat hardness as determined by all four methods. All hardness parameters were significantly correlated (r = 0.67 to 0.85). Low, significant correlations were found between 1,000-kernel weight and PSI (r = 0.27**) and resistance to ginding (r = -0.35**) and between NIR at 1,680 nm and protein content (r = 0.19*). Variance component ratios (sigma(g)(2)/sigma(e)(2) and sigma(g)(2)/sigma (ge)(2)) were much higher for hardness parameters than for 1,000-kernel weight or protein content. This indicates the relatively large and stable genetic, as contrasted to environmental, influence on hardness characteristics and variability. It is concluded that hardness of winter wheat is governed mainly by genotype and that some methods of measuring hardness may be influenced by kernel size. Grain protein content was not correlated with hardness when it was calculated for all varieties across all locations. Some varieties, however, showed significant (negative or positive) relationships between protein content and hardness. Those effects were expressed primarily in the two hardness methods based on particle size determination (PSI and NIR).