Nitrate Reductase Activity in Flag Leaf Blade and its Relationship to Protein Content and Grain Yield in Wheat (Triticum Aestivum L.)

The flag leaf blade of four wheat cultivars viz, Shera, Kalyansona, Heera and Moti grown at four applied N levels, which differed fir size, were examined for dry matter accumulation, nitrogenous constituents and in vivo nitrate reductase (NR) activity at various stages of development. At harvest, data for grain yield, grain protein percentage and grain protein yield was obtained. Dry weight bf the leaf blades increased till N₂ level while enhancement in NR activity was upto N₃ level. There was highly significant positive correlation of NR activity with; grain yield, grain protein percentage and grain protein yield viz., +0.75**, +0.72*, and +0.76**, respectively.