Nitrate Assimilation and Nitrogen Harvest in Uniculm 'Gigas' Wheat (Triticum aestivum L.)

Contribution of the upper laminae designated as 7, 8 and 9 (flag), to the total reduced nitrogen was determined by two different methods; integration of nitrate reductase activity over the entire growing season of individual laminae, and laminae removal at ear emergence. The values obtained by these methods were: 20, 14, and 12 %, and 23, 15, 12 %, respectively. The in vivo nitrate reductase activity was relatively higher in the lamina 9, which contributed an extra 8 % towards total reduced nitrogen when the other laminae were removed from the shoot. No such compensatory response was observed when either lamina 7 or 8 was retained.