Effect of wheat and barley varietal differences in nitrate concentration on plant analysis interpretation

Wheat and barley varieties from breeding plots in advanced yield trials were tested for NO₃ concentration in their stems at the tillering stage. The study was carried out for three years, at three different locations with a high number of varieties, aiming to determine whether there are varietal differences which could affect the interpretation of prognostic standards set up in a previous study.From nine comparisons between 12 different varieties it was shown that differences in NO₃ concentration occurred on only three occasions and these were due to factors which affect NO₃ in plants, other than genotypic.The study concluded that varietal differences in NO₃ concentration are not a critical consideration for the interpretation of prognostic standards for genotypes which have been developed for certain environmental conditions.