Nitrogen Relations During Spring Growth in Varieties of Triticum aestivum L. Differing in Grain Protein Content1

Abstract
Field‐grown hard red winter wheat varieties harvested at weekly intervals differed in plant nitrogen content, but the differences were not associated with the protein content of their grain. Plants of ‘Warrior,’ a low grain protein variety, were consistently higher in nitrogen thanhigher grain protein varieties. High protein derivatives of ‘Atlas 66’ ✕ ‘Comanche’ were intermediate or comparatively low in plant nitrogen. Their grain was significantly higher in nitrogen content than the low protein varieties throughout the grain development period. Nitrogen content of the grain first decreased from an initially high level, then increased during the last 3 weeks of grain maturation. In the high protein varieties the decrease was less pronounced and the subsequent increase more rapid than in the low protein varieties.