Nitrogen Metabolism and Yellowberry of Two Bread Wheat Cultivars1

Lath house experiments were conducted to study the relationship between the timing of N deprivation, subsequent N metabolism and yellowberry expression of two spring bread wheat (Triticum aestivumL. ‘Chinese Spring’ and ‘Anza’) cultivars. Wheat plants were grown in pots containing sand and were supplied with 350 ml Hoagland's solution containing 15.0 mM nitrate every 4 days. Plants were initially deprived of N (nitrate) at the jointing, boot, and flowering growth stages. Nitrogen deprivation at each growth stage increased percent yellowberry and decreased percent grain N. Percent yellowberry was inversely and curvillnearly related to percent grain N. The N metabolism traits which controlled percent yellowberry and percent grain N were percent above‐ground plant N, percentage of N in reduced form, and harvest index for dry weight and for N.