Potential for nitrate reduction in wheat (triticum aestivum L.)

Following the prevalent agronomic practice of applying N fertilizer in two splits at optimum levels recommended for maximum yield viz. 120 kg N ha, to two wheat (Triticum aestlvum L.) cultivars, which differ in in vivo nitrate reductase (NR) activity, it was observed that the activity is high in the first formed leaf blades and declines in the successively formed ones. Enhancement in the activity subsequent to incubation of excised leaf blades in NO₃ ^‐ suggests that the substrate (NO^‐ ₃) is limiting and that the leaf blades, particularly the upper ones, have the potential to reduce additional amounts of NO₃ ^‐. High NR cultivar has greater potential than the low NR cultivar. The studies suggest that it may be possible to increase the NO₃ ^‐ moles reduced and thus enhance the reduced N content in case the nitrogen is available at later stages of growth.