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; in tegration of nitrate reductase activity over the entire growing season of individual laminae, and laminae removal at ear emergence. The valu es obtained by these methods were: 20, 14, and 12%, and 23, 15, 12%, r espectively. The in vivo nitrate reductase activity was relatively hig her in the lamina 9, which contributed an extra 8% towards total reduc ed nitrogen when the other laminae were removed from the shoot. No suc h compensatory response was observed when either lamina 7 or 8 was ret ained.