Cultivar variation in nitrogen uptake and distribution in wheat

Abstract

Cultivar differences in nitrogen yield per unit area were identified at both heading and maturity, the ranking at both periods being similar. These differences were associated, initially, with the time at which leaf growth and expansion on a plant basis ceased. This period was later where the cultivar had a high tiller number, a large spread in phenological development between tillers, and a late appearance of the flag leaf relative to anthesis. The nett soil nitrogen uptake thereafter was associated with the leaf area duration and in the Mexican cultivars with grain yield. This association between total nitrogen uptake and grain yield and the possibility of influencing them independently is discussed.