Differences in Wheat Cultivar Response to Nitrogen Supply. II: Differences in N‐Metabolism‐Related Traits

Abstract

Two-year field trials with winter wheat cultivars Batis and Toronto were conducted in Southern Bavaria, Germany, to investigate the possible causes of cultivar differences in response to N supply varying in total amount and time of application. The results revealed cultivar-related differences in response to N fertilization in all parameters included in this study. Amount and timing of N fertilization was a strong indicator of N uptake into canopies and three phases of cultivar differentiation became apparent. Cultivar differences in N content were most clearly expressed during early growth stages, but distinctive differences in canopy N uptake were observed during later growth stages. Nitrate reductase activity, watersoluble carbohydrates (WSC), and plant nitrate content varied in response to N supply within cultivar-specific patterns that included reversals in cultivar ranking during canopy development, and provided additional indications for elevated intensity of N metabolism in cv. Toronto when compared with cv. Batis. Apart from such differences Batis partially compensated for delayed N uptake in earlier phases during the latter part of grain filling, presumably due to differences in root system development. Cultivar differences in regression of tillering, stand density, grains per ear and grain density (grains m )2 ) on a number of N metabolism-related parameters have been determined. They contribute considerably to the understanding of cultivar differences in grain yield components, as presented in an earlier communication. For 1000 grain weight, least affected from N supply within each year, large differences between years seemed to relate to differences in WSC content observed between heading and flowering, whereas cultivar differences in the level of grain N content and reaction to N supply were more directly determined by differences in N uptake and remobilization, and possibly enhanced by sink limitations of Toronto in grain size development.

Differences in Wheat Cultivar Response to N Supply. I: Differences in Grain Yield Formation

“…Attention was also paid to the effects of varied timing in N fertilizer application. While this publication addresses cultivar differences in yield formation in response to N supply, a second communication is devoted to differences in N uptake and N‐metabolism‐related parameters (Diekmann and Fischbeck 2005).…”

The Evaluation of the Compatibility of Cereal and Green Manure on the Basis of Nutrients

“…For cereals, N is necessary throughout the whole period of their vegetation. However, at different development stages the effect of N on the formation of grain yield varies (Diekmann and Fishbeck, 2005). Until now, little attention has been paid to the compatibility of cereal needs and fertilisation with green manure.…”

Varietal peculiarities of nitrogen remobilization from the vegetative parts of wheat shoot under different levels of mineral nutrition

“…Листок і стебло -найефективніші щодо реутилізації азоту в зерно [27]. Будь-яке підвищення врожайності пшениці має супроводжуватись збільшенням поглинання азоту та ефективності його використання [14,17,24].…”