Relationship between test weight and several quality parameters in wheat

Test weight has been used as a quality parameter of cereals in a large number of countries and is still employed to determine the price level. Literature studies showed controversial results concerning the relationship between test weight and flour yield as well as with other quality parameters. In this study, the data of a wide range of cultivars were analysed over several years to calculate the relationship between test weight and other quality parameters such as protein content, Zeleny index, thousand kernel weight and rheological characteristics. Analysis of variance for test weight of wheat showed important environmental and genotypical effects. No correlation was observed between test weight and flour yield in spring wheat. For winter wheat this correlation was negative, low but significant over two years, but not significant over the individual years. The correlation coefficients for wheat between test weight and grain yield, thousand kernel weight, grain score, falling number, grain hardness, protein content and Zeleny index were very low but generally highly significant, due to the large number of observations. The results in winter and spring wheat are not always similar. This is also the case for the correlations between test weight and a number of rheological parameters, where most of the correlations for winter wheat were very low but highly significant, whereas for spring wheat only the correlation with dough softening and viscosity were significant.The rapid method of measuring test weight remains widely used for the determination of price in cereals. It is demonstrated that this parameter gives no indication about quality or flour yield.