In situ nitrate reductase activity in winter wheat (Triticum aestivum) as an indicator of nitrogen availability

Early detection of N deficiency in a wheat crop using physiological and radiometric methods

“…Nitrogen stresses cause qualitative depreciation of crops [1] and affect plant growth by altering both leaf area and photosynthetic capacity [31]. Economic [12], chlorophyll content [9], plant N content [11,19] and nitrate reductase activity [7,36]. The nitrogen nutrition index (NNI) [18] can be used to detect N deficiency in a crop, but often only after the event.…”